EV3 and NXT: Difference and Compatibility

Since the launch of LEGO MINDSTORMS in 1998, three generations of MINDSTORMS products have been on the market:

  • 1998: LEGO MINDSTORMS (RCX)
  • 2006: LEGO MINDSTORMS NXT
  • 2013: LEGO MINDSTORMS EV3
Three generations of Programmable Bricks: RCX (left), NXT (middle), EV3 (right)
Figure 1: Three generations of Programmable Bricks: RCX (left), NXT (middle), EV3 (right)

Several LEGO sets have been released for each generation, but the Programmable Brick (Figure 1) is what makes each generation unique. Here’s an incomplete list of LEGO MINDSTORMS sets released since 1998.

  • LEGO MINDSTORMS (RCX)
    • 1998 – LEGO MINDSTORMS Robotics Invention System
    • 1998 – LEGO MINDSTORMS Education Set
    • 1999 – LEGO MINDSTORMS Robotics Invention System 1.5
    • 2001 – LEGO MINDSTORMS Robotics Invention System 2.0
  • LEGO MINDSTORMS NXT (See full article on NXT versions)
    • 2006 – LEGO MINDSTORMS NXT Education Set (9797)
    • 2006 – LEGO MINDSTORMS NXT (8527)
    • 2009 – LEGO MINDSTORMS NXT 2.0 (8547)
  • LEGO MINDSTORMS EV3 (See full article on EV3 versions)
    • 2013 – LEGO MINDSTORMS EV3 (31313)
    • 2013 – LEGO MINDSTORMS Education EV3 Core Set (45544)

All versions of LEGO MINDSTORMS NXT sets contain NXT bricks with the same functionality. NXT bricks found “NXT 2.0” sets have exactly the same specs as NXT bricks from other sets. Likewise, all versions of LEGO MINDSTORMS EV3 contain the same EV3 brick. So despite the large number of LEGO MINDSTORMS sets that have been made, only three versions of LEGO MINDSTORMS exist: RCX, NXT, and EV3. This article does not aim to introduce MINDSTORMS NXT and EV3 from the start, but it discusses some of the differences between NXT and EV3, as well as compatibility between the two systems.

EV3 brick and NXT brick compared

LEGO MINDSTORMS EV3 is the latest generation of LEGO MINDSTORMS, released in 2013. LEGO has stopped selling the NXT system in retail stores, but NXT products and support may continue to be available through educational channels for a while.

In general, LEGO MINDSTORMS EV3 is more powerful than LEGO MINDSTORMS NXT. If you do not have any LEGO MINDSTORMS sets yet, I recommend to go for EV3, so you’ll have the latest, most powerful LEGO robotics system to date.

EV3 Brick features

The main difference between the NXT system (the Programmable brick, motors and sensors) and the EV3 system is the brick itself. The EV3 brick features a more powerful processor, 4 motor ports (instead of 3), a micro SD card slot, a USB host port and a Linux operating system. In addition, it has a slightly larger screen, more buttons, and it is possible to control the EV3 brick using both iOS and Android devices, as opposed to Android only for the NXT. See this article for a list of technical specifications of both bricks.

Why a micro SD card slot, a USB host port and Linux?

On first thought, you may wonder why you would need these features. First, the micro SD card slot can be used to add extra storage to the brick by means of a micro SD card. Additionally, the USB port can be used to link up to four EV3 bricks so that you can control up to 16 motors and 16 sensors on one robot.

EV3 Brick with Netgear WNA 1100 WiFi dongle. This configuration provides an alternative to USB or Bluetooth when programming the EV3.
Figure 2: EV3 Brick with Netgear WNA 1100 WiFi dongle. This configuration provides an alternative to USB or Bluetooth when programming the EV3.

Although the general user will not notice on the outside, the brick runs a Linux based operating system. Basically, this means that your robot almost resembles a full computer, a bit like the Raspberry Pi! This means that you can add other devices to the USB port on the brick, such as a WiFi dongle for wireless connectivity (Figure 2), a USB keyboard for extra input, or a USB webcam for object detection.

Note that while the possibilities are endless in theory, we’ll have to wait for people in the LEGO MINDSTORMS community to develop specialised software for such devices, so that the rest of us can use them on our robots. For example, before you can use your USB keyboard as a ‘sensor’ inside the LEGO MINDSTORMS EV3 software, someone will have to create a custom sensor block that tells your robot which buttons on the keyboard are being pressed.

EV3 Motors and EV3 Sensors

Both versions of the EV3 set come with a variety of sensors (see details; coming soon). If you have an NXT set, you’ll recognize some of the new sensors. The EV3 Touch sensor, EV3 Color Sensor, EV3 Ultrasonic Sensor (Education set only), closely resemble their NXT counterparts. New sensors for the EV3 system include a gyroscope (Education set only) and an Infrared Proximity Sensor with Remote Control (Home edition only). Figure 3 shows the complete family of EV3 electronic components.

Complete family of EV3 electronic components (not every component is included in each set).
Figure 3: Complete family of EV3 electronic components (not every component is included in each set).

Both versions of the EV3 set contain two Large motors. They are comparable to NXT motors in terms of speed and torque, although their shape is slightly different to make building easier. In addition, both sets have one Medium motor, comparable to the Power Functions Medium motor. As is the case for NXT, all three motors have rotation sensors for position and speed control.

Hardware Compatibility

The cable connectors in the NXT sets and EV3 sets are the same, so that many of the EV3 and NXT devices can be used together. Some combinations are compatible, others are not, as discussed in the next. You can see a demonstration of two possible configurations in the following video.

Most NXT accessories can be used with the EV3 brick

You can connect all official LEGO NXT motors and official LEGO NXT sensors to the EV3 brick. For example, you can have a configuration with an NXT Touch Sensor, an EV3 Touch Sensor, an NXT motor and a Medium EV3 motor, all connected to the EV3 brick, as shown in Figure 4. You use the NXT devices in the EV3 software as if they are EV3 components, as demonstrated in the video.

Possible configuration with one EV3 Brick with both EV3 and NXT accessories.
Figure 4: Possible configuration with one EV3 Brick with both EV3 and NXT accessories.

You can also connect some unofficial NXT Sensors to the EV3 brick, such as some sensors from HiTechnic, Mindsensors and Dexter Industries. However, these companies will have to create programming blocks to facilitate the use of these sensors in the LEGO MINDSTORMS EV3 software, which has not yet been done for all sensors. If in doubt, contact the manufacturer of the sensor. If you have a very old version of the NXT Touch sensor, it may not be compatible with the EV3 without some modifications (see the comments by Philo below).

EV3 sensors CANNOT be used with the NXT brick, but EV3 motors CAN be used with the NXT

It is not possible to connect the new EV3 sensors to the NXT brick. However, you can use both Large and Medium EV3 motors with the NXT brick as if they are normal NXT motors. Figure 5 illustrates this (see video above for a sample program).

Possible configuration with one NXT Brick with various motors and NXT sensors.
Figure 5: Possible configuration with one NXT Brick with various motors and NXT sensors.

The NXT and EV3 rechargeable batteries are not compatible

Both the NXT and EV3 can be powered with 6 standard AA batteries. Alternatively, they can be powered with a LEGO rechargeable battery. The LEGO EV3 battery and LEGO NXT battery have a different shape, as shown in Figure 6, so you cannot use them interchangeably.

Due to different plastic connectors, you cannot use the NXT rechargeable battery on the EV3 brick, or vice versa. LEGO sells two types of chargers as shown, so be sure to order the right one.
Figure 6: Due to different plastic connectors, you cannot use the NXT rechargeable battery on the EV3 brick, or vice versa. LEGO sells two types of chargers: AC and DC, so be sure to order the right one. This image shows central European wall chargers.

Software Compatibility

The EV3 brick is programmed with new programming software. Although the software is different than the NXT programming software, existing NXT users will recognize many of the features of the EV3 software. You can still program the robot’s actions using drag and drop programming blocks, as shown in Figure 7.

Two equivalent programs in the EV3 software (top) and NXT software (bottom).
Figure 7: Two equivalent programs in the EV3 software (top) and NXT software (bottom).

It is also possible to use the EV3 software to program your NXT bricks. If you have both NXT and EV3 bricks, this allows you to program both using just one application. Note that this does not give your NXT brick additional features. For example, you still cannot use EV3 sensors on the NXT brick. It just helps keeping all your programs in one place. The EV3 software (home edition) will be a free download from the LEGO MINDSTORMS website [click here], so you can use it even if you do not have an EV3 set.

Questions & Updates

Feel free to post questions in the comments below. I’ll try to answer your questions and add them to the article if necessary. If you find any errors, please let me know.

All text and illustrations in this article (c) Laurens Valk 2013

321 Responses
      1. Moltas

        can you connect the ultrasonic sensor from the NXT brick to the ev3 and program it. And can you connect a Nxt and an ev3 together???

        Thank you for this article, i found it really helpful.

        1. Laurens

          Sure, an NXT Ultrasonic Sensor works fine on the EV3.

          Technically, EV3s and NXTs can cooperate, but not using the standard EV3/NXT software, so the short answer is no unfortunately.

          1. Peggy

            We currently have lego mindstorms nxt (from 8 yrs ago) and missing some pieces. I have found an original lego mindstorms 2.0 complete on craigslist. Do you think they would be compatible?

    1. The EV3 Home edition software will be a free download for home use, which should be available on the LEGO MINDSTORMS website as soon as the product is launched.

      1. robantwerp

        hya Laurens

        Firstly great comparison, this already helped me alot.

        But I am all new to this and thinking of buying EV3 for my boys (10 + 12) and am rather confused and overwhelmed with information (or lack of)

        1. is the educational pack 45544 better than the 31313. Namely is the brick from 45544 different as I am wondering if I won’t need the extra software 200045 needed to test and fine tune components. Or can I use this educational software also with the 31313 ?

        The reason I ask is because I am also thinking of getting a second EV3 brick + extra building parts so that together they can build one larger robot (3-4 motors seems a bit limited to me if you are considering moving two legs, two arms, torso and maybe the head + having hands to pick up things ?

        2.
        which type of motors will i need for arms and torso since I don’t know the difference between the large and medium nxt motors (which i read you can use on the EV3).

        3.
        also am confused about the bluetooth commander app : it says you can control your robot with the app but does a camera exist (and programming in the brick) that you easily build on the robot to see on tablet where the robot is looking at and going (ie streaming). My son now has a parrot jumping sumo and would be nice for the lego robot to have similar capabilities

        I myself used to be a lego fan so I am excited to sit with my boys and build a nice robot with them. However as a lawyer and not an engeneer I hope I won’t have to write programming myself but can use the programming tools in the EV3 brick

  1. Bert Lindeman

    Thanks Laurens, nice post as ever!
    Do you know of a reason why LEGO made the battery packs for the EV3 different from the NXT one? Except marketing reason of course….
    The chargers will cause confusion no doubt.

    1. I don’t have an official source for this, but I believe the design was in part influenced by new EU regulations that require two seperate locking points.

      1. George

        Where could I purchase the rechargeable battery kit for EV3? I have already spent $50 in batteries and I can’t find any rechargeable ones. I have checked E-bay and was unable to find any offers . Could someone please tell me where to get them or could someone post a link to an E-bay page or other online website that sells them (I live in NZ and many large department retailors have no stores there).

        Many Thanks, George

        1. Rand0mUser

          I’ve found that some Amazon basic batteries work brilliantly. They retain their charge for ages and don’t seem to affect motor speed. Alternately, and this is something I’m working on, you might be able to connect some huge D type batteries using a few crocodile clips, wires and elastic bands — but I don’t know if that would work, or if it would burn the brick. Anyone know if that’ll work?
          Here they are — http://goo.gl/Y0rQcT

          1. someone

            D batteries will not hurt anything, as long as you do not exceed the maximum input voltage specified for the controller. The D batteries will give you more current, or the same current for a longer time. The capacity of a battery is measured in Amps/hour, or milliamps/hour for small batteries. When you place batteries in series positive to negative to positive etc. +_+_+_+_ the voltages add up. When you place them is parallel, with all of the negatives connected together, and all of the positives connected together, you get the same voltage but more current is available.

  2. John Hansen

    My understanding is that the EV3 rechargeable battery had to differ from the NXT rechargeable battery because the battery compartment now has to have 2 mechanical latches (or a screw) due to toy safety regulations. But both batteries use the same DC charger.

    1. Leigh

      The charger on the EV3 is different to the NXT. It has a much smaller connection to the battery, so they are not interchangeable even if battery voltage is the same.

      1. Have a look at the diagram in this post discussing the two types of chargers. I believe the DC charger for EV3 is the same as the charger for the white NXT battery.

        The dark grey NXT battery requires an older AC charger.

    1. This isn’t a history of LEGO MINDSTORMS as to not confuse the reader 🙂

      I included the RCX mainly to show that one generation stays around for more than 5-7 years, which could help people decide whether or not to upgrade their LEGO MINDSTORMS collection.

    2. Michele Davis

      The RCX (1998) was released before the Scout and Micro Scout (1999). There are also a number of other programmable bricks that you failed to mention – Dacta Control Lab (1995; stationary robots only), Code Pilot (1997) Cybermaster (1998), and Spybotics (2002).

  3. Ray McNamara

    Thanx for the info Laurens.

    My under standing from initial reports was that the I2C EV3 Sensors were backward compatible with the NXT.

    Is it purely down to LEGO’s NXT-G software, meaning I would have access via RobotC, LeJOS or NXC with firmware fixes?

    1. Hi Ray,

      I understood that most of the new sensors communicate wih the EV3 brick using UART (serial), while most digital NXT sensors use I2C. EV3 has UART, I2C and Analog – hence the backwards compatibility. The NXT does not support UART.

      Maybe someone experts this subject can find ways around this, but the article/video here describes the out of the box experience. The schematics have not been released yet at this point, so we’ll have to wait and see.

      On the other hand, there isn’t much reason to buy EV3 sensors for NXT, since comparable sensors are already available for the NXT.

      1. Chambo

        I find it extremely hard to believe they willbe using uarts to communicate with the sensors. It is a much older and slower and less flexible technology than i2c.

        1. Ray McNamara

          Yes, for some unbeknown reason, UARTS have made a resurgence?

          I even notice that a lot of “Raspberry Pi” Add-ons now feature UART Interfaces.

          UARTS are used for asycronous serial communication. No clock is required and the timing of the bits is determined from the leading edge of each character. A minimal full-duplex interface requires three wires, TxD(Transmit Data), RxD(Receive Data) and Ground. The full duplex means there can be data going in both direction at the same time.

          I2C is sycnronous data transfer with a data line and a clock line. It is half duplex, meaning data can only go one way at any given time.

          UART is a point-to-point communication i.e. only two devices talk to each other, you can not connect extra device on the same UART (unless your using using RS485 drivers/lines)!!

          I2C gives freedom over that, you can connect as many as 128 devices on the same 2 wire line (with 7-bit address range), saving a lots of wiring for you!!

          It’s also important to mention that the I2C interface supports clock stretching, where devices that need more time to receive and process data can pull the clock line low (due to being designed to be open-drain) to tell the master device that it’s not ready. Though I2C can theoretically support 127 devices, your average I2C slave device can’t have it’s address fully configured..

          1. Rand0mUser

            It seems that UART is being used for the much higher data polling rates the EV3 supports (1000Hz compared to 333Hz or something), and perhaps they needed to move to UART because of I2C speed problems? I’m no expert, but I know a little.
            And I don’t know anyone who needs to be able to use 128 sensors on one port (!).

        2. someone

          plain serial is a lot simpler, easy to implement, and built in to all sorts of embedded devices with very simple resources. It is extremely easy to use with Linux. If you have no need to network a large number of sensors with few conductors, plain serial is easy and used very often, older or not.

  4. Luke Taylor

    So not even the Ev3’s touch sensor is compatible??? Does the EV3’s software still freeze up in moving large programs around, or is that fixed?? And what new features of the software were introduced, or is it the same??? Any new blocks other than motor/sensor blocks???

    1. Hold on. LEGO has done an excellent job at backwards compatibility this time. Why would you need the EV3 Touch sensor on your NXT anyway? In order to step forwards, they’re using technology that’s simply newer than the NXT.

      For the moment, I’m using Beta versions of the new software, so I can’t be sure about performance. You will be able to try for yourself with the free download that will be available when the set is released.

      The software contains various new blocks, such as array blocks.

    1. Unfortunately, no. It will only run natively on Windows and Mac.

      However, there will be other community based programming environments available for Linux.

    2. Ray McNamara

      Unfortunately the growing number of Linux users are ignored yet again. Mac O/S is Unix based, and is almost identical to Linux in may ways.

      The easiest fix would to run a WindowsXP Virtual Machine and install the EV3 Software on it.

      This option works great for NXT-G, RobotC, & BricXCC. I have also run the RIS Environment in the same manner.

      This link will get you started: http://www.rjmcnamara.com/lego-minstorms/bricxcc-running-linux-2/

  5. MauroPerez

    Great article! Thanks!.
    The new software compatibility for both NXT and EV3 means that it will be posible to configure robots with both EV3 and NXT (Master / Slave). Is that correct?.

    1. I don’t think this is currently supported, but I haven’t tried. The hardware should allow this, so perhaps community supported software will once have this feature. Not sure they’ll add it to the standard software as well.

    1. Yes, but not yet! I expect members of the MINDSTORMS community to start working on those API’s as soon as they get their hands on the EV3 set 🙂

      I’m expecting to see EV3 versions of LEJOS, NXC, ROBOTC and possibly much more.

  6. john osborne

    I’m in a quandary about using the EV3 in my Robofest Robotics club for a Middle School. You say to get the EV3 but our school has NXTs. Should I allow parents to bring in an EV3 even though it will create issues having the two different models?

    1. It shouldn’t create technical issues, perhaps only confusion on the part of people who do not know the difference.

      Remember, I said to get EV3 if you did not have any NXT yet. If you already have NXT, you’ll have to make your own choices to stay with NXT or not.

      1. Ronna

        My team used an EV3 this past fall, and the team is growing and I am able to get my hands on some NXT robots.

        If I have a group of kids learning and playing around with 3 NXT’s and 1 EV3, using the EV3 software, do you see any challenges with the mixed boxes with a group of kids? I am thinking that maybe I can put colored stickers on each box, and any of the motors and sensors that came with those to help keep them straight. I don’t think the EV3 motors and sensors are backward compatible.

        I have played around with the EV3 software on the NXT and the NXT medium motor did not work. I was able to get the large motor to work. The color sensor, touch sensor, and the untrasonic seemed to be recognized and it appeared that the sensors will work, though I have not tried to create a program combining the motors and the sensors yet, and think that is something that the kids can play around with and explore.

        What do you think?

  7. Jasmine

    Does the Linux system mean we’ll be able to add other languages, like RobotC which I use on the NXT? Does it mean we won’t have to wipe the whole thing and start over, and might be able to switch between the two without any flashing? Cuz, that would be cool 🙂

  8. Janez

    Hello!

    Nice post Laurens!

    My question is about compatibility of P-bricks… Is it possible to connect EV3 and NXT 2.0 P-bricks like master/slave configuration via bluetooth or even USB?

    Many 10x for the answer,

    Janez

    1. Hi Janez,

      That’s a good question. I just tried connecting via bluetooth. The connection seems to work, but I’m unable to make a program for communication with the standard EV3 and standard NXT software. So the hardware allows this, but the software does not (yet) support it. I do not know if LEGO will implement this feature in the future.

      However, developers of alternative programming environments may be able to implement this.

      Laurens

  9. Elliot

    So, I’ll ask.

    When will the EV3 be out? I know August 1 is one possible date, but when I called Lego they just said “Fall 2013”. My son’s birthday is August 2nd, and its killing me.

    Thanks for article!

  10. Tim

    Do you know if the EV3 will support RCX sensors like the NXT did? I have a lot of older mindstorms parts I would like to continue using. Even if not on a software level, does the hardware support it?

    Thanks in advance.

    1. I think so, since the NXT supported it, and the EV3 has at least the same capabilities. The question is whether it is implemented in the firmware, which I do not know.

      1. Andish

        Out of the Box the x1676 Electric Mindstorms NXT Conversion Cable does not work for the analog input, as the EV3 checks for presence of NXT-Sensors by using Pin2 as an Input that shall be grounded to Pin3 by the NXT Sensor.

        The cable was designed not only to attach Sensors, but to be a motor / Lamp / Led driving cable as well, thus only connecting Pin 1 and 2 to the two poles of the RCX / PowerFunctions 2×2 stud connector.

        Now Lego has two options it could give us in the future:
        * write a Raw Sensor Block that could use Pin2 as OUTPUT and put out LOW, hoping for a stable low Voltage as “temporary GND”.
        OR:
        * produce a cable that has e.g. some 1kOhm resistor from Pin 2 to 3 and attaches Pin 1 and 3 to the two RCX poles.
        By the protective resistor (in contrast to just shorting it) you will not be able to damage the motor port if someone accidentally plugs a reworked RCX adaptor in.

        Hopefulle it will be before FLL, we needed it.

        Thanks for asking LEGO about RCX sensors. There are many uses to them.

        Andi

    1. From the Read_Me_EV3_home.txt in the installation directory:

      Operating systems:
      • Windows: Windows XP, Vista, Windows 7, and Windows 8 (excluding Win RT) (32/64 bit) with the latest service packs
      • Macintosh: Mac 10.6, 10.7, and 10.8 with the latest service packs
      System requirements:
      • 2 GB of RAM or more
      • 2.5 GHz processor or faster
      • Minimal supported screen resolution—1024*768
      LEGO® MINDSTORMS® EV3 does not support tablets or certain netbooks with hardware that does not meet the above requirements.

  11. PeterLPS

    Will programs developed using NXT Mindstorms import into the EV3 software? That is do we have to recode existing programs and ‘My Blocks’?

  12. Henry Cate

    I downloaded the Education EV3 and have been trying to get started. There is a lesson on Multitasking that implies you can drop a path similar to what we do with NXT. I cannot catch the flow path and split it. I can get a spread, so there is a place to grab, but if I try, I wind up moving a block.
    Do you have a piece of magic to share?

    Thanks

    1. John F. Davis

      After the first output is attached as an input to the next block, I bring out the block that will be run in parallel and drop it unattached on the screen. Then I left-click and drag another data line from the first output to the input of the unattached block. Finally I arrange everything to look nice.

    2. Andish

      Hello Henry,
      could you share the link, please please 😉 ?

      I’m a coach for some FLL kids, and would like to play around with EV3 soft before term starts, leaving me a week now to get a little bit ahead of them and try to anticipate their questions…

      Thanks!

      Andi

    1. John F. Davis

      I have installed and briefly used the Education version on Snow Leopard, Windows Vista, and Windows XP. No problems yet.

    1. Julie Smith

      I am looking for the 4 extra builds that are shown with the education version, particularly gyro boy. I purchased the education and home edition. The home edition software is all I need, but I would like instructions for the other education builds that seem to be only available with the education software. I am hoping that someone knows somewhere else that the instructions can be found.

      1. tabbycatrobots

        I too would like to build the education version robots, but
        do not need the data-logging or classroom management software,
        and the $100 cost. Does anyone know if LEGO.com or LEGO
        education might offer the education version robots build
        and program instructions for something like $20 – $25? Thanks
        for any ideas.

  13. Kara

    Thanks for this great article! Do you have any thoughts on the education versus home set, and which I should purchase? Is the programming language identical between the two and it’s simply a matter of which parts each set comes with, or are there more subtle differences I don’t know enough yet to be aware of? 🙂 Thanks for your input!

  14. Ian Chow-Miller

    Hi Laurens,

    Great article. Two points:
    1. You are right about the reason for the new battery; the EU requirements have been confirmed to me by LEGO Ed. reps.

    2. I can not get a USB drive to work for storing information like an on brick program or the results of datalogging experiments, I can only store those on an SD card. Is it possible that the USB slot is only for wifi dongles and the like and not storage?

    Thanks,
    Ian

    1. Hi Ian,

      Thank you for your comment.

      USB sticks are supported in hardware but apparently the current firmware does not support it. I’ll correct this in my article. Thanks.

        1. No, the EV3 programming software will not be available as mobile apps.

          However, there will be some iOS and Android apps that will let you control your robot remotely.

  15. Clint Johns

    I’m having trouble getting my EV3 brick to turn on with the rechargeable battery. It worked once when I first plugged in the rechargeable battery (and after the first full charge). But the following day, I tried to turn it on again, and only get a quick flash of the red LED. I took out the battery, recharged it to 100%, and even tried a different EV3 brick, all with the same result. I then put in 6AA batteries, and the brick turned on fine.

    I am thinking that the issue might be similar to the NXT one, that being the spring connection to the rechargeable battery is bent just enough to no longer make contact. But since the battery doesn’t appear to be working on 2 brand new EV3 bricks makes me wonder if the battery is somehow defective…?

    Any help would be greatly appreciated – the school year starts next Monday (8/26) so I would really like to get a fix identified before then!

    Thank you all in advance!

    1. Leigh

      I just got an email from the supplier that there is a fault with some of the batteries which perfectly fit your description. there has been a recall.

      1. I can confirm what Leigh says. If you experience issues with your battery, contact your supplier, or contact LEGO directly.

        Contacting LEGO directly is usually the fastest way to get a (free) replacement.

  16. Leon Chen

    You said: “It is also possible to use the EV3 software to program your NXT bricks.”…

    But, when I try Tools/Firmware Update, I got the message:
    “This tool is not supported for the NXT Brick.”

    Do you have solution?

          1. carlos

            Indeed this works. We updated several NXT’s to firmware 1.31 using the old NXT software and now it works with the EV3 software perfectly.

  17. Leigh

    Great article. I am disappointed that I didn’t get the IR sensor in the kit. Had I known I would have bought the home edition and used the NXT sensors with it. This article helped me figure out why I couldn’t get infrared to work as I assumed the ultrasonic sensor did both functions.

    1. That is correct. You cannot connect EV3 sensors to the NXT brick.

      However, you can purchase the IR Link from HiTechnic, which has (some) similar features if you have a Power Functions remote.

      1. Andish

        Hi Thomas!
        NXT brick to EV3 soft with BT:
        BT for me is always a bit picky, instable.
        No automatic reconnect with EV3. Perhaps no one has this…
        No connect at all with NXT brick from EV3 soft.
        Perhaps I should invest some $ in a bt stick with widcomm stack besides the microsoft one…
        Andi

  18. Bart

    If I create an EV3 project on a Mac, can I copy that project file to a Windows machine and edit it in Windows? I’d read that NXT project files couldn’t move between OS’s, but I was wondering if this was fixed for EV3.

  19. David Salak

    NXT motor blocks allowed you to designate the motor using a variable and wires. My initial look at the EV3 software seems to preclude motor selection using variables and wires. Do you think this is correct?

    1. It’s still possible. In the port setting (top right of motor/sensor blocks), click the plug icon, instead of A, B, etc. Another input plug on the block now appears.

  20. Alex

    Great article, useful comparison. Does the NXT light sensor (9844) work for the EV3. My initial test show not supported. Any other tried?

    1. Tim

      I just tried it on mine: worked fine. In the software, use a color sensor block. Select either reflected or ambient light. The brick will automatically configure itself for the connected sensor. So the same program will work with the EV3 color sensor, NXT color sensor, or NXT light sensor.

        1. Tim

          It will still work if you are using the NXT color sensor, but I could not get the light sensor to function with a color block. There is a way you can cheat though: if you use a NXT sound sensor block, that will use the light sensor. Use dB for reflected. And dBa for ambient.

  21. Andish

    Hello!
    Perhaps some of you think of complementary completing their sets from edu to play store version or vice versa.
    In ideal someone would buy sets and split them to “complementary halves” and sell the bricks/Sensors seperately, so I could get what I want with some clicks.

    The educational EV3 Part List is part of the available pdf instruction.
    http://cache.lego.com/r/education/-/media/lego%20education/home/downloads/element%20overviews/mindstorms/45544_element_survey.pdf?l.r=-477601429

    Choose a language there:
    http://www.lego.com/en-us/mindstorms/downloads/user-guides/enus/
    Or enus:
    http://www.lego.com/en-us/mindstorms/downloads/user-guides/enus/

    Perhaps I’m late and someone has made a difference-list of the kits?

    Have fun!

    Andi

  22. cotiso

    Crappy forward compatibility !

    If you want to reuse a NXT program (most likely a complex one) with EV3 IDE program, it seems you cannot open it !

    The only option we’ve found is to open in the old NXT IDE your old .rbt program and recreate it manually within the new interface, generating the new .ev3 project.

    Is there any other option anybody knows?

    1. They’ve done a great job on compatibility in my opinion. They’ve made sure that all of your investments in NXT hardware maintain their value.

      Consider rewriting some of your programs as a good way to get to know the new software. Maybe you can even make them more efficient now.

      1. carlos

        Yes, the EV3 software is great but there should be a conversion tool to change the NXT code into EV3 code, because there is such a HUGE library of programs out there in NXT that should not be just trashed 🙂

        1. Andish

          I’ve heard of FLL teams doing their programming in a high langueage like Java and letting a tool convert i.e. compile it to NXT-G.
          This could be a solution, because if this tool (call it compiler?) gets updated to write EV3 files it could perhaps be tought to read NXT-G as well as input.

          Does anyone know the kname of the NXT-g compiler?

          Thanks!
          Andi

  23. Steve Ives

    Hi,

    The Mac software requirements posted above state a ‘2.5Ghz’ processor. elsewhere it states a 2.0ghz processor. However there is a big difference in power between a 2.0ghz Core duo and a 1.7ghz i5 (which my Macbook Air has).

    So does anyone know if it will run on an Air? (with Turbo Boost up to 2.6GHz).

    Steve

    1. My PC/Win7-64 has a 1.7Ghz i7, on which it runs fine. I don’t have an air to try it out.

      But since it’s a free download – feel free to try it out and post your findings here for other Macbook Air owners to see 🙂

  24. Steve Ives

    Thanks – I’m sure it’ll work fine, but I didn’t want to go home (I work abroad) only to find that the software would refuse to install due to a CPU speed check. I have a MacBook Pro 2.6 i7, but wasn’t going to take it home.

    But from the sound of it, it doesn’t check the machine’s specs.

  25. Chris

    Thanks for this writeup – it’s very clear. I’m researching robot kids for myself and my kids. Can you tell me how much programming you can do directly on the brick itself? Does complex programming require a PC or Mac? My kids don’t have a computer, and aren’t likely to anytime soon, so I’m interested in how much programming you can do without a computer. Thanks!

  26. Science Teacher

    We have 2 new EV3 robots and we cannot get them to charge nor turn on. It seems like they are charging but then we cannot get them to come on. All we get is a quick red flash then nothing on the screens. Ideas? Please help!

      1. Try to rule out some possible problems to see what may be going on.

        To begin, try your EV3’s with fresh, standard AA batteries to see if the EV3 brick’s themselves work fine. If not, the Firmware may need to be updated to resolve this.

        There is a known issue with the batteries, but you seem to be describing something different.

    1. Snowy Owl

      I had this same problem, it turned out to be the rechargeable battery. Try Laurens’ suggestion below about AA batteries. If they work, the rechargeable battery is the likely culprit.

  27. Peter

    I have the EV3 Education and Expansion Kits and am running the education software. Three questions:
    What pieces are required extra to build the Home(retail) Kit models?
    Where can one get building instructions and programs for the Home Kit models without having to download the complete programming program (over 600MB)?
    The iPad App doesn’t have building instruction for the Education Kit models?

  28. Branch

    I am a teacher and am new to lego robotics. We have an NXT brick that we are trying to run on the EV3 software. Our EV3 brick runs fine, but the NXT will not work. We did a firmware update and it connects to the software now but it says file error on the NXT brick whenever we try to download and run a program. Any ideas? I am very new to all of this so any help would be much appreciated.

      1. NeXT-Generation

        The EV3 software does currently work with the NXT, albeit in a limited capacity. It’s possible that your program has blocks in it that the NXT is incapable of writing. Try just a basic sensor reading or motor moving program. I didn’t have to do anything special to get my NXT to work with it.

  29. iwjev

    How would rate the backwards compatibility of the EV3?

    I cannot get it to recognize option 2 (button push and release) of an NXT touch sensor. I also cannot get it to recognize a RCX (using the converter cable) sensor/motor at all. I am guessing it is because they changed the touch sensor from digital to analog (so they can measure the degree that the sensor was pushed). So while the NXT sensors can technically work on the EV3 I hope the make blocks specifically for the NXT and legacy(RCX) sensors/motors.

    1. The EV3 is able to detect both a press and a release of an NXT sensor. If you want the brick to detect ‘bumped’ (option 2), just wait for a press, and then a release.

      The RCX, NXT and EV3 Touch sensors are all on-off switches. None of them detect to what degree a button is pushed.

      RCX compatibility doesn’t seem to be supported out of the box.

      1. iwjev

        So uf I am reading this correctlyIif I want to test bumped I use 2 blocks. 1 for pressed and then 1 for released. I will have to play with that tonight.

        I also hate to say it but you are wrong about the ev3 sensor. If you go to the lego education youtube channel and watch the vudeo on the touch sensor he says it is an analog senson that advanced users can program for the degree of press. To see this in the code look at the two optuons for the touch sensor. You demonstrated the bottom option that has 3options 0 push, 1 release, 2bumped. Check out the other touch option in it it has a defree setting.

        1. The statement in that video is not correct to my knowledge, but we’ll have to wait for the hardware schematics to be sure.

          Bumped (2) is just a combination of pressed and released, and the software provides this option for your convenience.

          1. iwjev

            I just looked up the help on the touch sensor and it looks like you two are correct. the odd thing is that the “measure” state name doesn’t really make a lot of sense if it is only pushed or not. Additionally the icon is a ruler implying that you are measuring the distance that the sensor was pushed. I wonder why they changed it. could it be that it was to hard to make the analog sensor or maybe they realized that it is not feasible or worth while to measure the degree a push on such an small button.

            When I said I could not get the bumped to work, I meant with a NXT sensor. the bumped works great with the ev3 sensor.

            also, and I am sue it is just me, but I am personally ecstatic that I am having a conversation with you and philo about the workings of the different sensors. 🙂

          2. Hi Iwjev,

            I agree, the whole thing about Compare, Measure and Change has not been a good design choice in my opinion. Configuring sensors is more confusing now than it needed be.

            It may well be that you have discovered a bug in the EV3 software when it comes to the NXT Touch Sensor. They’re supposed to work in the same way, after all.

            Oh, I remember being new to the community as well – but it turns out we’re all just normal people 🙂

            Laurens

          3. Philo

            Actually it’s more complex than it appears…
            Here is the summary…
            – NXT touch sensor connects pin 1 to ground (pin 2) through a 2.2k resistor
            – EV3 touch sensor connects pin 6 to +5V (pin 4) through a 2.2k resistor.

            On the software side, I found no behaviour difference between NXT and EV3 touch sensors, be it on pressed, unpressed or bumped events, all work fine.

            BUT!!! early NXT sensors had no connection between pins 2 and 3, while later ones have these two pins shorted. The early touch sensors are not detected by the EV3, as can be seen in Port View screen. These early sensors do not work at all with EV3, whichever mode is used.

          4. iwjev

            There must be a middle nxt sensor because I have an early one from the nxt 1.0 line (but I don’t think it is one of the very first).

            With my EV3 my NXT touch sensor work on pushed, released but not on bumped. I wonder if I would contact lego if they would do anything about it… might have to give it a try.

          5. Philo

            I am not aware of this 3rd version, but maybe? I tested 4 NXT sensors here, 2 were early version and not working, two were working fine.

          6. iwjev,

            If you say that your EV3 detects both pressed and released, then your NXT sensor works fine.

            As I’ve pointed out before, bumped is not a special sensor value – it’s just a combination of pressed and released.

            If the following does not work:

            WaitForBumped

            Then try the following:

            WaitForPressed
            WaitForReleased

            Which does the same. The bumped not working for the NXT sensor is perhaps a bug in the EV3 software.

            Laurens

      2. Philo

        For sure, EV3 software works fine here with my recent NXT touch sensors. Maybe iwjev has a defective sensor? For example excessive contact bounce that does trigger a bug?

    1. Philo

      You mean, using Bluetooth? I tried, (using LEGO programming software), but failed. As far as I understand it is not possible – but I’d be very happy to be proven wrong!!!

    2. anton

      Yes! I want this too! I actually bought an EV3 thinking I was going to be able to make bigger robots, with the NXT and EV3 connected. I hope my NXT brain doesn’t become obsolete…

  30. anton

    How can I make the NXT color sensor shine with the ev3 software? There is no button to set the light to a certain color. (Or I can’t find it)

    1. There is no ‘Lamp’ function for the Color Sensor in the EV3 software.

      You can now control the EV3 Brick Status Light instead, but for the NXT, you’re ‘in the dark’ 🙂

      1. Bert

        Right Anton. We deerly miss a color lamp block. On the rac3truck bonus model I added one EV3 color sensor and one NXT color sensor. The model is the EV3 brick. It is a bit of misuse, but if you ONLY want to shine a light, it can be done:
        1) put the color sensor into measure-color mode and both EV3 and NXT color sensor shine bluish-white.
        2) Put the color sensor into measure-reflectedlight mode and both EV3 and NXT color sensor shine RED.
        3) Put the color sensor into measure-ambientlight makes the EV3 sensor turn dark-blue and the NXT sensor goes OFF.

        It’s not much, but you can shine a light like this.

  31. Julian Mankuto

    Hey- I need a quick within the hour answer- I need to make a sensor that tells me what speed an object is going, know anything? Please answer ASAP. 🙂

  32. Sergio

    Hi! Excelent post!

    I have a question. I am working with my NXT brick but i have a problema. This weekend we have the WRO College category challenge in Peru, me and some friends work at one robot for it. The problema is that our programm is too big for NXT brick and we have not the resources to buy an EV3 brick. Is there any form to extend the memory of nxt brick?

    Thanks a lot

    Grettings from Peru

    1. iwjev

      Have you tried to shrink your code. You can save a lot of space by turning some code sections into mycode blocks. Since mycode blocks are smaller and reusable you can in a sense shrink your program.

  33. Abishek Dharshan

    Excellent Summary, Sir.

    Doubt – Does the EV3 have the same diversity in creative programming ( creating ur own stuff) as the NXT

    THanks

    1. iwjev

      HT has said that all sensors are supported but they have not yet released an ev3 block for them all. Atthis time I do not thonk that the gyro block Iis out yet. Of course you could do what I did and by the lego gyro sensor from lego esducation.

  34. James Smithson

    How about software compatibility between NXT and EV3? can one send the other a bluetooth message, and can I expect it to react if I use the included programming on the computer right? For example, if the NXT is is programmed to send a bluetooth message (“TEST”, for instance) to slave port 1 at the press of a touch sensor, and the EV3 is programmed to rotate motors B&C for example, when the touch sensor is pressed on the NXT, will the message (TEST) come in from master port one (The NXT), and will the EV3 react and rotate its motors? PLZ reply and enlighten me, as I’m planning to get an EV3 for a project that will only work if they are bluetooth compatible.

  35. Ray

    Hi Laurens,

    Do you or anyone else no if the Netgear ‘WNA1000M’ G54/ N150 Wireless USB Dongle will work with the EV3?

    The main difference that I can see between the Netgear WNA1100 & WNA1000M is size. The WNA1000M pertrudes only a few millimeters out of the USB Socket.

    cheers

    Ray

    1. Hi Ray,

      As far as I know, there’s really only one dongle that’s supported by the standard EV3 firmware (Netgear WNA1100).

      Other people have already managed to install other WiFi dongles (it’s a Linux box after all), but they use their own firmware.

      Laurens

  36. sher

    Hi Laurens,

    I have a brand new Lego Mindstorms NXT 1.0, which I purchased on eBay but I haven’t got around to building anything yet. In the meantime, someone has offered to sell me EV3 at a decent discount to market price. I’m wondering whether I should pay for a brand new EV3 and start learning the ropes on the latest version or should I first try to get to grips with the older NXT 1.0 set that I have. The EV3 offer seems bit good to pass, hence the dilemma. Who knows that by the time I have mastered NXT1.0, EV4 would already have been launched!

    Is it worth splashing on EV3, when I haven’t even learnt/mastered NXT?

    Thanks

    1. Hi Sher,

      You could consider taking the middle route and program your NXT with the (free) EV3 software. Whether or not you’ll get the new hardware in the future, you’ll have to learn just one programming language.

      Laurens

    2. Leigh

      In my opinion apart from a very few improvements, like the fourth motor output the EV3 is not much more than a facelift. Buying the Ev3 will guarantee a little more futureproofing, but it wouldn’t significantly improve your robotic experience.

  37. Paul

    If I buy the EV3 Education core set, can I use the free EV3 “Home” software? Or am I required to purchase the EV3 Education software?

    1. The Home EV3 software will work fine, since the EV3 brick in both sets is the same. You can install blocks to use the Ultrasonic Sensor and the Gyro separately from the LEGO website.

  38. Sara

    Hello Laurens:
    We are about to start a robotics program for K-6 and we have been advised to purchase the EV3 kits. Are these too complex for our littlest students? Also, since I will be the one learning to program them, (and I haven’t been able to find a training course for the EV3 – only the NXT) will learning NXT programming be a good start for me, or should I try to learn the EV3 programming from the instructions on the EV3 software? I learn pretty quickly, but I really like being in a class in which I can ask questions.
    Thanks so much!!

    1. Hi Sara,

      I think you’ll probably want to start with EV3 if you’re new to MINDSTORMS. That way you’ll have the latest version of everything, so you’re more likely to get support on your product on the long run.

      I expect EV3 learning material to come out as time passes. For example, I’m working on a new book to explain EV3 programming in detail.

      How old are the youngest students in your robotics program? I believe the set is rated 10+, but perhaps 8 or 9 will work too if they have someone who guides them through the material.

      Laurens

  39. wattminder

    For technologists, EV3 is revolutionary because three
    of its new features:
    1 Open source Linux computer, similar to the Raspberry Pi
    2. Web-connectivity through USB WiFi dongle, tablet interface
    3. Point-and-click programming (MIT’s Scratch ) core in its desktop Mindstorm software

    It is THE prime example of how MIT’s Scratch technology can be adapted into a complex programmable domain, to allow students and teachers to configure the hundreds of pieces, dozen of sensors and actuators to flex
    one’s creative muscles to create interesting robots without using a programming language like Python or C. I predict the EV3 will evolve and grow tremendously, given time.

    1. Andish

      Hi Laurens,
      have you seen how the One and Only WiFy Dongle is hard-coded in model and type in the firmware?
      Maybe Lego has stock lasting long enough, given its horrendous price tag; but for me it is old hardware (150Mbit) that is big and clumsy to attach.

      Please all of you wanting to attach a stick that is available in a few years from now and doesn’t slow down your future 1GBps WiFi network:
      ask Lego for a firmware where the driver module for wifi dongles can be easily replaced.
      And where ALL WiFi-USB-Sticks that are supported by some active driver will be allowed to work by lego (what a nuisance!).

      I predict there will be a market for USB cables that have super thin foil cable to allow for 0,3mm thickness and a non-protruding plug to get the dongle attached without sticking out 😉 I plan to look out for such a (solderable) foil cable and do an USB extension that will fulfill this demand..

      Has anyone seen a app for Android or iOs that does something useful? OK, the existing play apps are fun, but I hoped to gain access of the smartphone sensors for the EV3. I hoped I can edit stored programs there. Have live view of variables and Sensors, use the internet connection of the smart device and relay on via bluetooth.
      In my plans more often does the smart device travel along with EV3 than sitting in a childs hand to remotely steer it.
      I think RC is fine and ok, but the more interesting way of machines evolves when you have the tools to do a fine balanced shifting of emphasis between a more remotely controlled job and on the other end of the spectrum a totally autonomous acting robot doing his mission.
      I ponder how to make this clear to youngsters and what is missing out-of-the-box in EV3 (edu or home) to start in this direction.

      Yours
      Andi

  40. Chet

    I have a EV3 brick and the Ultrasonic sensor from the older mindstorm set 8527, and using the most recent Labview software on windows.

    I am trying to test the robot for distance and to stop a few cm from the wall. The WAIT block included does NOT have an option for Ultrasonic Sensor, but has one for Infrared Sensor, which does not seem to work. Have any of you seen this behavior?

    Thx!

    1. Hi Chet,

      You’ll need to download the Ultrasonic Sensor block separately from LEGO.com/MINDSTORMS.

      It is for both the EV3 ultrasonic sensor and NXT ultrasonic sensor.

      Best,

      Laurens

  41. Sara

    HI Laurens:

    I just pre-ordered your book. Looking forward to it! I wonder if you could answer a question I have about the ipad app and the EV3? I have just started using the app to control my robot, but I don’t immediately see how to actually program it. Is it possible to program it using the app as you can using the software? How do the app and the software connect? Thanks so much!!

    Sara

    1. Hi Sara,

      The apps allow you to control your robot remotely, but you cannot program it from the app. You can only program it from a computer (Windows or Mac).

      For tablet programming, perhaps you can try one of these new full Windows 8 tablets. (It does not work on Windows RT devices, though.)

      Thanks,

      Laurens

  42. Jesse

    Does the EV3 eduction kit have more than the home, and if I just want it to tinker with it and build robots (not the included ones), what other kits/parts should I buy?

  43. cindy

    I’m planning to give the EV3 version as a gift. Is the NXT 2.0 Discovery book helpful in this case, or would it just confuse the kids? They are 10 and 12, not very tech-savvy.

    1. Hi Cindy,

      Unfortunately the NXT 2.0 Discovery Book would not be helpful in this case. You’ll need the new edition: EV3 Discovery Book, but it’s not out yet.

      I’m working very hard to finish it 🙂

      Thanks,

      Laurens

  44. Paul

    ABOUT NXT AVAILABILITY. Your article is a HUGE help. I run Robotics And Beyond in CT and NXT is our mainstay for intro-level robotics. I plan to buy only EV3 from now on but also have a learning curve to go through. I have forwarded your article to a number of parents needing guidance for Christmas gifts. As of 12-12-13, LegoEducation.com still sells the NXT 2.1 system but cust. service told me that it will be available for another year or bit more but not after that. See link below for all NXT 2.1 products and prices. NXT 2.0 is discontinued. I have noticed that prices on auction sites for NXT 2.0 and 2.1 sets have gone up by about $100. I assume partly due to their replacement by EV3 and partly due to holiday demand. NXT bricks are still around $130-150 for new. I have poor results buying used bricks and recommend against it.
    http://www.legoeducation.us/eng/product/lego_mindstorms_education_nxt_software_2_1/2240

    1. I’m glad to hear you found the article helpful. Once you’ve decided to go for EV3, you might want to check out this article as well, which covers the difference between two versions of the EV3 set:
      The Difference Between LEGO MINDSTORMS EV3 Home Edition (#31313) and LEGO MINDSTORMS Education EV3 (#45544)

      Note that there is no NXT 2.1 “set”, only an updated version of the software: 2.1. LEGO isn’t making it very easy for their customers 🙂

      I tried responding to your comment but my message disappeared – sorry if you received it twice!

  45. Anonymous

    there should also be a temperature sensor for the EV3, but i don’t know any advantages of getting it. is there any differace between the new one, and the one from older versions?

    (by the the way, I didn’t want my name to be disclosed, and I don’t have an email that would be eligable for this)

    1. I suppose that’s what nicknames are for, right? Now we’re all just curious about your motives for using the temperature sensor 🙂

      It’s a good question, but I don’t own either temperature sensor, so I can’t help you.

  46. Philo

    It was indeed intended initially to create an EV3 specific temperature sensor, but it seems that this was cancelled. NXT temerature sensor is the only one presently supported in EV3 Education EV3-G.

    1. Rand0mUser

      No, the EV3 and NXT motors are (almost) identical — all are accurate +/- 1 degree — so their position is accurate to within a degree. You can use NXT, EV3 large and EV3 medium interchangeably on both the NXT and EV3 with no side-effects.

    1. Philo

      Thanks for using my joystick 😉 Unfortunately the messaging protocols used by NXT and EV3 in Bluetooth communication are different, and I couldn’t get them talk together…

  47. FrancoisImpey

    I have tried the NXT touch sensor on the EV3 and it is NOT compatible. Since I have a few of these and really want to use them on my EV3 I investigated it further. The NXT sensor switch connects a 2k2 resistor between pins 1 and 3, with all other pins unconnected. The EV3 sensor is much more complicated. I converted the NXT sensor to be EV3 compatible, by removing the existing 2k2 resistor, shorting pins 3 and 5, adding a 910 ohm resistor between pin 3 and 1, and changing the switch to switch the 2k2 resistor between pins 4 and 6. It is now detected and works fine. Why this sensor isn’t compatible I’m not sure. Waiting for the EV3 HDK to investigate further…

    1. Philo

      You effectively converted your NXT touch sensor into a true EV3 one. The problem you had with your NXT sensor is because you have an early version, as I said in a comment above:
      “BUT!!! early NXT sensors had no connection between pins 2 and 3, while later ones have these two pins shorted. The early touch sensors are not detected by the EV3, as can be seen in Port View screen. These early sensors do not work at all with EV3, whichever mode is used.”
      Somehow the best method to convert these sensors is to short pin 2 and 3 as they become compatible with EV3 and remain compatible with NXT

      1. FrancoisImpey – good to hear you found a solution, and thanks Philo for keeping an eye on this blog!

        I’ll update the post to reflect this.

        If you don’t want to open up a sensor, you can just modify a cable instead to short the black and the red wire (2 and 3).

  48. gairlochan

    How about the ultrasonic sensor in the NXT Home Edition kit? I have it, and I can’t see any support for it in the downloaded EV3 Home Edition software, and the NXT software which came on CD with the kit only runs on PPC Macs, not Intel Macs like mine, so I can’t use it.

    I really want to use the ultrasonic sensor; any ideas on how I could get it to work with the EV3 Home Edition software?

    BTW, I’m amazed that the NXT’s ultrasonic sensor has been replaced in the new EV3 kit by an infrared sensor and IR remote. Surely that’s a move in the wrong direction from the point of view of robotics proper (i.e. autonomous machines as opposed to remote control toys).

    1. You need to install the Ultrasonic Sensor block from the LEGO MINDSTORMS EV3 website: http://www.lego.com/en-us/mindstorms/downloads/ev3-blocks/ultrasonic/

      In the EV3 software, click Tools > Import Blocks, then select the downloaded file and follow the steps on the screen.

      The IR sensor is not a step backward in my opinion. The ultrasonic sensor can sense only distance. The IR sensor can do that, and much more:

      Proximity mode (approximate distance to any object)
      Beacon Heading mode (direction of the IR signal)
      Beacon Proximity mode (approximate distance to the remote)
      Remote mode (detects which button on the remote you press)

      The IR distance sensing is less accurate that the ultrasonic distance measurement, but you get a lot more functions instead. For example, you can create a robot that autonomously finds the infrared beacon.

      I cover all of these modes, with many example programs, in my new book. http://robotsquare.com/books/ev3discovery/

      1. gairlochan

        Thanks for the prompt and detailed reply; I do appreciate it.

        I’ve got those blocks installed now, and am just going to do some tinkering and see if I can set up the ultrasonic sensor on my current Legobot.

        I knew that IR sensors are used in robotics for distance measurement, but I didn’t know the Lego IR sensor did double duty (indeed, quadruple duty); I’ve only ever used ultrasonic sensors on my robots.

    2. Philo

      The EV3 US-sensor block available here http://www.lego.com/en-us/mindstorms/downloads/ev3-blocks/ultrasonic/ does support NXT US-sensor.
      As for the IR sensor, the inclusion of remote can be discussed (I personnally like it because it makes robot mechanical debug easier), but the IR sensor itself works great as an obstacle detection device, it’s much more reliable in many instances (wall at an angle, soft curtain…). Granted, it doesn’t deliver true distance and has a shorter working range.

  49. Peter

    Does anyone know if the EV3 software running on a Mac under Mountain Lion will communicate with the NXT brick through bluetooth? The NXT bluetooth software crashes newer MacBooks with a broadcom bluetooth chip. I’m considering upgrading to the EV3 software and if this bug is fixed I might make the jump.

    1. The EV3 software can control the NXT only over USB.

      The software is a free download and you can install it without removing the NXT software, so you can always give it a try to see if you like the new programming.

  50. Brad

    This is probably way out in left field but I have an old RCX kit but the brick no longer works. I’m looking at getting the new EV3 kit for my kids and I was wondering if you might know whether it is possible to get the RCX motors and/or any of the sensors to work with the EV3.

    Thanks

    1. I don’t think this will work, especially not right away. You may be able to use at least the Touch Sensors if you created a custom cable to make them work. The same holds for the motors.

  51. Norman Dunlop

    How robust is the new EV3 processing chip? What are LabVIEW programmers saying? If you made a pen plotter, would you program in LabVIEW, or would you program in another language?

    1. The graphical Labview software is quite good. I tend to use it for all of the projects that I share online or in books, to make it easier for beginning programmers to recreate my programs. A pen plotter would work fine with this software.

      Perhaps if you were to create software that would convert an actual photograph into a black and white image to ‘plot’, you would have to consider alternative languages.

  52. Alex Ferris

    Hi
    My friend has the 2006 NXT software and I have the 2013 EV3 software but I can still connect which is great. Some functionality is greyed out but otherwise it’s fine. My question is can I add Robot C to a block of my own? We are trying to add a switch statement to allow the sensor distance to be registered so that sound output can play like a theramin. We can’t work out how to use the visuals to do this but are itching to add code to do detect the sensor input.

    Any pointers (!) are welcome. Thanks. Robocoder.

    1. Rand0mUser

      You can use the sound block in the EV3 software and data wires to do this, hope you understand how I’m writing this:
      INFINITE LOOP
      Infrared sensor block <– Block type
      |Distance output <– Output
      | <–Data wire
      |Tone input of <– Input
      Sound block (play tone mode)
      (END INFINITE LOOP)

  53. Leigh

    I realise this is not quite the right forum, but you guys are the BEST source of brainpower on the interweb. I am having to reinstall my NXT software on my computers. Which version came with the bluetooth remote control option? It was on my old copy but not on any of the new versions. Is there a way to install this feature into the 2.1 version?

  54. marr

    is it possible to program an eve 3 lego robot to perform multitask?

    like looking for a green box inside a boundary of a red a tape with out going out of the red boundary? and after that program it to place the green box on a green area inside the red boundary

    1. Tim

      The main limitation of the home software is the lack of data logging. It comes with some blocks already enabled, such as the sonar and sound sensor blocks. But those are relatively easy to put into the home version.

      1. Richard

        Hello Tim,
        I’ve just tried the EVA3 home ver. software to control my NXT, but the ultra-sound sensor is unavailable. How can I put this sensor service into EVA3 soft?

  55. NEEL JAIN

    I have a nxt 2.0 kit, but the batteries have leaked inside the brain , hence, it doesn’t work, so should i look around for another nxt 2.0 brain or can i go and buy a single ev3 brick so i can use it with my old 2.0 accessories

  56. David Salak

    I have observed that the sign of the “degrees of rotation” parameter changes the direction of motor spin — not just the sign of the “power” parameter. Reasonable behavior. But I have also observed that the direction of rotation is actually the algebraic sign of the combination of the two signs — if both are negative the motor spins forward which I found to be unexpected. Is this documented someplace that you are aware of? If I make use of this “feature” I run the risk of it being deemed a bug and getting “fixed” in and my programs spontaneously failing at some point in the future.

    1. Yes, that observation is correct. I’ve documented this information in my upcoming book.

      I consider it a very useful feature. Especially if you use the output of a certain equation to control the ‘angle’ (Degrees, or Rotations) as well as ‘power’, negative signs can result naturally, and then this is the expected result.

      If you’d like to change this behavior, you could use a Math block in ABS mode to remove the sign from any negative number.

      Another subtle thing to note is that ‘power’ isn’t actually power, but it sets the speed. An internal program automatically increases power if the measured speed drops below the set speed.

      1. David Salak

        First — Thanks for the quick reply and comments. I would need more background to understand when negative power and negative degrees would be used in a computation where their signs would combine resulting in wanting to move forward when both were negative. But yes — I just absolute valued the degrees before passing it to the motor for my case. This puts the program in compliance with the EV3 documentation. Still, while I don’t quite understand how this might be useful, I would like to have the option of being able to use it, should the situation arise, unless Lego considers it a bug that they may change in a future firmware release. It would help if this behavior was noted in the EV3 Help section that talks about the motor parameters, their values, and actions caused.

        Second – While I knew that speed was a function of power I did not know that the brick managed it as speed and compensates for depleting battery. Good info, thanks again.

        1. Hi David,

          There is other information in the help section that is incorrect as well. I suspect some of it has been written before the final software was ready.

          I don’t know what LEGO would change in the near future, but I’m hoping they realize what harm this type of change would do to FLL teams. In any case, you can always save a copy of the V1.01 (current version) and back it up for later use. When new versions come out, they might pull the old one from their site.

          Negative degrees values could be useful, for instance, for a stationary robot arm that rotates around its base. To make the control easier, it’s nice to keep 0 degrees for the forward pointing position. Then you could use negative degrees values to go to the left or positive values to go to the right. There are other ways to do it, of course, but this method makes the program easier to understand.

          The reason I think that this isn’t a bug, is that they did prevent the user from entering negative time in On For Seconds mode of the Move blocks. (If I recall correctly – I can’t check right now.) If they wanted to prevent negative Degrees or Rotations values, they would have changed that as well while they were at it, I think.

          1. David Salak

            It’s the negative degrees AND negative power combining somewhere inside the brick to produce a positive motion that I think is odd and possibly a bug to be fixed. I cannot think of a situation where I would want these two negatives to produce a positive movement. If someone makes them both negative they probably want negative rotation.

            I actually prefer having negative degrees reverse the motor for the reasons you mention.

          2. David,

            I don’t think that’s odd. It’s a natural consequence that follows from the two inputs.

            The following situations can cause the direction of the motor to change:

            a) negative angle
            b) negative speed

            If both situations occur you change direction twice, and therefore you go forward.

            You can also think of it as multiplying two numerical values, giving positive when you take two negative inputs.
            1×1 = 1, -1×1 = -1, 1x-1 = -1, and -1x-1=1

  57. A A Gruntpuddock

    The ‘power sign’ is very handy, you can reverse a motor at any time by multiplying the power by -1, you don’t have to keep a record of which way it is going.

  58. Bill H

    Great forum! I am trying to control the two large motors and two NXT motors from the EV3 brick using two subroutines. Each sub works fine independently but, when run together, the NXT motors (ports A and D)run very slowly and “chatter,” while the EV3 motors (ports B and C) perform as expected. Any suggestions?

    1. Rand0mUser

      Could be to do with how it controls the motors — if possible, use unregulated motor blocks for the NXT motors and use a wait until rotations block to control distance. Use the current power mode to check it is going fast enough, and stop it with a motor: off block.
      ALSO
      Check batteries — the EV3 motors may be drawing more power than the NXTs and causing this.

  59. Jan S

    I teach at a norwegian high school, and we have 13 NXT bricks and hope to get 1-2 EVO sets as well. Based on what you have written here, it should not be a problem to have the whole class working off the EVO software, even though most students are using the NXT bricks. I have found the NXT-G software frustrating at times, especially the interface for connecting variables between the hubs. Is this experience any less frustrating with the EVO software?

  60. Kowalski

    Dear Laurens, nice article!
    I wondered if it is possible to use the EV3 gyroscope with the NXT Controller programmed with RobotC. Maybe the EV3 sensor could be set as a third-part sensor with a specific driver to obtain a retro-compatibility.
    I look forward an answer from you.
    Best regards,
    Kowalski (Italy)

  61. Vishnu

    Can a Samantha Module be used with EV3??
    If not, is there any way to remote control an EV3 robot with another EV3
    or a ROBOTC program?

    1. Rand0mUser

      Samantha modules are a little pointless — it’s only a way of accessing the internet, right? You can use a wireless USB network adapter for it — search around.
      You can send messages between EV3 bricks using Bluetooth — connect them and use send/receive message blocks in EV3-G.

      1. Vishnu

        I have a project coming up an would like to know if i can control an EV3 with a game controller like NXT through ROBOTC.

  62. Leigh

    Two questions, firstly does the EV3 workwith RobotC yet and if so which version?
    Second, Does anyone know if you can use RobotC to operate a joystick of some sort through bluetooth?

  63. April

    I have 10 NXT kits to use with my students and no computers. I have access to iPads can they be used to program the brick.? Do I need any adapters or apps ?

  64. Leigh

    Is anyone using RobotC? I am having some issues with the NXT on RobotC and would like some suggestions from anybody. Also is RobotC available for EV3 yet? If so what version?

  65. Aryan

    i have ev3 and nxt both, but was just wondering that can i program ev3 to control nxt or vice versa, via bluetooth?

  66. Shalini

    I am FLL coach and some of my team kids are looking to buy the Lego Set for 2014. SOme of us have both EV3 and NXT and some needs to buy new set. Our experience with EV3 was not that great last year tournament. We had lot of issue besides the brick froze in the middle of the tournament.
    What do you suggest to buy for new team members – EV3 or NXT?

    1. Leigh

      I have also got both Ev3 and nxt bricks. I have defintiely had issues with the ev3 in preparing for robocup competition events this year. This could be my liited programming, but they seem to react differently to the same programming.

  67. cads56

    I have been given vi files from the nxt system. Will I be able to use them on the EV3 system and if not, is there a way to copy them/replicate them for the EV3system? I am new to using the Lego robots and can use all the help I can get. Thank you.

    1. Rand0mUser

      You can remake a program in the EV3 software that was made for NXT. The EV3 and NXT software cannot open each other’s programs BUT the ‘language’ hasn’t changed really between them. You should be able to remake the program easily with a little experience in the new software. The only difference is that some options are removed in the new environment (e.g. motors ‘Wait for Completion’) but these are easily recreated (e.g. wait block ‘Wait until’>’Rotation sensor’/’Motor’>’Degrees’ = ).

  68. legonewbie

    It a good and subscriptiv page you made, Mr. Valk. Very Impressiv!
    My questions are:
    – Is the Mindstorm EV3 also in though for Adults or are there more the kids involved?
    – If there is such a big diffrence between the Edu-pack and Home, what does realy make more sence to buy of the EV3 edition?

    Let me know, also the Volks allready using it! Bye

    1. Rand0mUser

      The Mindstorms sets are aimed at children (building and basic programming) and adults (building, basic programming, advanced programming, even hacking are all recommended by LEGO), but work best with children who can or likely to be able use computers very confidently, program and think logically.
      Normally this means over about 13. If they end up leaving it alone for ages (like I did), don’t despair! They may, all of a sudden, go back to it — just get the set out yourself, do some advanced stuff with it, let them teach you, do whatever.

      The home set is easier to acquire and has more models available for it online and in books. The education set is better for teachers because it includes lesson ideas e.t.c, but is more difficult to buy and more expensive, as well as not looking quite as nice. I would recommend the home set for home, and the education for schools and clubs.

  69. Leigh

    Hi guys, I would appreciate some feedback from anyone who has used the EV3 fairly extensively. I have found them to be a bit glitchy. Recently I was at a Robotics Tourney and I heard someone describe them as “unstable” Is this your experience with EV3? I really want to consider this as I need to invest in at least 50 kits over the nextfew years and am wondering which path to take.

      1. leigh

        I have found that some of the demo programmes for the scorpion and dog thing don’t tend to work as they should, when I try using a hitechnic infrared sensor v2 it just crashes the robot, and I could NOT get it to do rescue for the Robocupjr competition. Is this me or the platform?

        1. Some of those may be problems with the demo programs, rather than the hardware. Further exploration will be required to find the real cause.

          I know that there are some issues with the LEGO firmware when using third party sensors such as sensors from HiTechnic. The most recent update (1.06) should fix most of these issues.

          1. Michael

            There is an issue with I2C poling on the earlier firmwares. I have noticed that I2C data will clash or even overwrite other I2C sensors with 1.06. Even if your sensors are on different ports with different addresses.

  70. Michael

    You can use EV3 sensors with the NXT brick if you have an EV3 sensor adapter from mindsensors.com. It also allows you to put EV3 sensors on a splitter to run them on the same port if you are running out of ports.

  71. Jabul

    Did they ever come up with a simple fix for the incompatibility between Mac operating systems and NXT Mindstorms 2.0? My Mindstorms software always crashed when I opened it. I found various fixes on the internet. I used a thoroughly kluge one for a while–uninstalling flash player (the source of the problem) then reinstalling it when needed. I mucked around with various attempts to use older versions of flash player. One of the questions that arises there–As time goes on, just how old a version will be worth using? There were other suggestions, links, etc., and differing reports from various people as to how well these suggestions worked. I eventually just started using other computers to which I have access.

    Now I’m running Yosemite on my MacBook Pro. I downloaded the home version of the EV3 software. It works fine. The NXT software still crashes as soon as I open it. I could just let things go as they are. However, some of my students, colleagues, associates, etc. have written good programs that I’d like to run on my Mac. If you know of a simple solution, I’d be happy to hear it.

  72. Leigh

    Have Lego pulled out of supporting NXT? I have misplaced my 2.1 software disc and want to install the temperature sensor block to 2.0 Every source ends up redirecting to EV3 instead. Very frustrating

  73. John Kauffman

    I’m new to Lego platform, so let me know if naïve. I will start working with students next month and have been told the school has a mix of NXT and EV3. My basic question is if I can handle both with one laptop.

    1 – Does anyone have experience with installing both programming software packages on one Windows machine?

    2 – Same USB driver?

    3 – Can I expect conflicts if I am going through student projects and alternately plugging in NXT and EV3 bricks?

    Thanks.

    1. Leigh

      Hi, I teach mostly with NXT but also do a little with ev3. Short answer is no, you shouldn’t have a problem using both platforms. However I have found that since switching from xp to seven, (which I delayed until the last possible second) that there are definite problems with NXT labview software. Ev3 is a bit glitchy too in certain areas, mostly around imported hitechnic blocks. Both of these issues are with the software itself rather than having them both on the same machines. At the end of the day I go through about 350 students a week and may only get an issue every other month. If you want things to go smoothly, computers are not for you.

    2. Michael

      Installing both software packages should not be a problem. With windows 8 I have seen that NXT firmware will not upgrade. Keep in mind the EV3 programming environment is compatible with the NXT brick and programming is much easier. The only thing to remember is the display is set up differently. The lines are reversed and the text has to be resized.

  74. Michael

    Is it possible to build all or most of the models from NXT 2.0 with a EV-3 set? Adding some more lego technic parts or EV-3 sensors is not a problem, but do EV-3 motors and sensors allow to build exactly the same designs just following the instructions of NXT 2.0? What are the obstacles, if any?

    1. The EV3 motors have a slightly different shape, so you’ll have to modify the designs accordingly. And one of them is replaced by a Medium motor. The NXT just had three large ones.

      1. Michael

        Thank you. I will buy an additional big EV3 motor if there is a need, but after I have 3 motors, is it a complicated task to adapt most of lego NXT2 standard robot designs to EV3?

        Did anyone try that?

        1. Well sure, I have done that for several NXT robots in my book. For example, there was the NXT Snatcher, and now there is the EV3 SNATCH3R.

          I basically redesigned it from scratch, although that was mostly because the EV3 set came with very different building elements.

          Anyway, just give it a go and use the NXT robots for inspiration in your own EV3 designs, but don’t worry too much if it turns out somewhat different than the original.

  75. Gildardo

    Hi Laurens;

    I have Matlab 2013 and only allows me to download the hardware support package Lego Mindstorms NXT but I purchase the EV3 brick system. Can I use the Lego Mindstorm NXT support package from Matlab/Simulink (2013) to run the EV3 ?

    Regards

    Gildardo

    1. Leigh

      Hi Robo, my experience is that every time I try to use the hitechnic Infrared 2 sensor the robot freezes. Like pull the battery out frozen. I got told through this forum that a new firmware and programme update would probably fix it. Haven’t tried yet. Other than that I had physical issues getting four motors to fit inside the size limit allowed under RoboCupJr regulations. To me having four wheel drive would have been a big advantage, but the physical restrictions limit this.

  76. Eria

    Hello,

    Can you run at the same time two different programs that are in the same ‘PROGRAM FILE’ but they are not connected? (the one in near the other one but not connected with a wire or something else- 2 different loops)

  77. Ivo van der Wolf

    I use EV3-home-edition. My hardware is NXT. The software do not recognize the infrared sensor (ultrasonic-cm). is says: This block or mode is not supported on the connected brick.
    Quenstion: how can i use my NXT-ultrasonic-cm with EV3 software?

  78. IvanHoe

    Hei Laurens, thank you for the great comparison between LEGO Mindstorms NXT 2.0 & EV3. This is my 1st encounter with them and your write up is FANTASTIC!

  79. Andish

    Hi there !
    The Touch Sensor again… EV3 vs. NXT:

    (Motivation: I wanted to attach a hall sensor from a geared DC motor to EV3.
    Not very useful, since I can only count up to 400+ Hz as the max. Loop frequency in EV3. Still…)

    Using the NXT touch sensor setup, bridging Pin 2 to 3, EV3 does NOT want to show the status in the Port View. Since this small box in EV3 Soft is very useful, I want it to show.
    So I have to emulate an EV3 touch sensor. Reading the following, you can even re-wire or build an adaptor doing the translation NXT->EV3 touch sensor, or whatever digital or even analogue source of signal you can imagine:

    Using multi meter, I found the internal wiring of the EV3 touch sensor likely to be:

    * 3 to 5 with a wire, 0 Ohm. (5 as digital input LOW, one bit of “Sensor ID”)

    * 1 to 3 with a 0,9kOhm resistor (reading out analog value? Could be it’s coded to several “Sensor ID bits”)

    * 4 to 6 with 2,2kOhm in serial.

    Since 4 is +5V (20mA?) ==>
    _______________________
    Pin 6 is the actual input.
    ===============

    Since it is LOW when the switch is released, it is drawn to ground (Pull-Down mode).
    When using digital outs you may have to include some pull-ups or pull-downs, until you have set the thing to the right threshold giving you stable operations.

    Just use a poti, Ends at gnd and V+ (Pin 3 and 4) and a digital volt meter at the variable resistance pin to pin 6 to verify at which voltage it switches.

    Don’t forget the 0,9kOhm on 1-3 and to bridge 3-5 even for this little test.

    I found a surprise here:
    The input is read out analogue, in port view on the display of EV3 there is a bar graph that is proportional to the voltage applied at pin 6.
    1,17V: bar is at left end, “0 bar”, and at 2,5V the bar reads “full”, “100% bar”.

    And at 1,82V it switches the digital reading above the bar graph, without any noticeable hysteresis.

    I can only interpret this readings as a implementation of a true ability to attach force sensors, but the final touch sensor hasn’t coped to be so cheap as to utilize some proportional sensor design to actually deliver analogue signals. So we got a dumb 0-1 switch. What a waste and pity…
    So go and build your own, there are millions of cheap ways, and every peace of consumer electronics, be it old printers or video tape recorders, offers sensors and electronic parts enough to go to creative mode 😉

    At least you can use the sensor port view with the bar mode to check for broken cables with unstable contacts 😉 If the bar is shaking unstable, something is wrong with the wiring or the switch inside the Touch Sensor needs some Switch Spray.

    So I place the output of my Hall sensor device (it is a IC actually and gives out digital signals) on Pin 6, plus wire and resistor as above.

    You can decide if you place some resistor in serial by watching the resulting voltages at pin6. A signal is digitally fine when both Voltages for logical 0 and 1 are well away from the 1,82V.

    If you need drawings circuits or photos comment here.

    Have fun!

    Andish

  80. beaken

    I use the new EV3-software but an old NXT (education pack 9695). Everything works fine but the lightsensor. Do I need a new firmware on my nxt or isn`t it compatible?
    The lightsensor works fine with the old nxt-software.
    Thnks a lot,
    beaken

  81. Jim

    I have found it is a good practice to keep an extra rechargeable battery available if you are involved in a competition that lasts more than 4 hours. This seems to be the threshold for LEGO when something really begins to go wrong on the brick. What I mean is when battery power begins to wane on the EV3 the brick begins doing funky things that its not programmed to do. When this happens pull out a fresh & fully charged back up battery and drop it in and the programming glitches will go away. If someone knows why this is happening or can fix it via firmware please step up an fix it. This one glitch alone can make or break your team in long competitions. This is also another difference between the NXT brick and the EV3 brick. Any ideas here?

  82. Jezzroy

    Hello. I’m a former NXT 1.0 user and prospective EV3 user; my NXT brick no longer works, it seems. Or at the very least, the rechargeable battery I used has gone bad. It was the older one. My EV3 set is going to be a birthday present.

    Anyway, I have a question. Having read various comments, I am beginning to wonder if my old Touch Sensor will function properly with EV3. I need to know how I can tell, as I don’t know if the newer NXT Touch Sensors were at any point packaged with the 1.0 kit. I’ve never had an opportunity to buy the 2.0 kit.

    I can live with it not functioning with the EV3; I can’t be bothered to do hardware modifications on my NXT stuff, and I may only need the one EV3 Touch sensor anyway for my builds, but I like knowing what my options are.

  83. Jerrell

    Does the EV3 Robot Commander also work with the NXT brick? If not, is there older software that I can load on my iPhone that will command the NXT brick, and where can I get it? Thanks.

  84. oliver

    Hi i have lost some parts ( 1 wire and remote) so i was trying to know what type of wire EV3 uses or what website to buy new parts from PLS HELP

  85. monty

    Great article! Do you know where I can find a chart comparing the functions of NXT vs EV3? I want to use the EV3 software, but I only have NXT bricks.

    thanks!

  86. James Bryan

    Will the Energy Meter that connects to the Solar panel in Education kit 9688 work as a sensor feed into the EV3? I know it was designed for the NXT. Thanks, James

  87. JsnLn

    Hey, Im a student using EV3 programming software, but with NXT set. I have the NXT brick, sensors, everything, except the software for programming.

    It’s been working out for me, until I reached a problem.

    I used to work with EV3, and I could set the Move Tank to be ON, and it will keep rotating. I can then add a Wait Block so that it moves on when it, for example, detects a wall. This is really useful and I decided to use this for a new project, which I’m using the NXT set for.

    However, when I set it to ON, it just rotates for 1 rotation, and then stops. This really annoys me, and I don’t know if this is just something I programmed wrong, or if this is something that’s not compatible between EV3 and NXT.

    Thanks,
    JsnLn

  88. Andish

    Hi JsnLn !
    Have you used the blue unregulated motor block? If it is “always on” – OK, then just don’t use the Tank move block.
    We were always disappointed with the (not-) precision it can go straight or keep track on a circle with some radius.
    So we programmed a “curve follower” instead of a line follower, just weigh the angles from the motors with a clever factor and subtract. The result is the error, some factor to it, and put it on top of some base power level for the one motor and subtract it from the same base power level for the other.
    The amplifying factor can be increased until the motors begin to stutter, then decrease a good bit to stable operation.
    Here you have the recipe for some easy PI-control on the relative angular velocity for steering. Because the angle is the integral of the angular velocity 😉
    Have fun and report if it worked out.
    We have used the function lego obviously uses as “steering” -100…100 by drawing a chart with sectionally defined linear functions and re-built this input to our circle follower to be a my own block imitating the steering characteristics of the lego motor block with the steering wheel (avoiding any divide-by-zero problems thereby 😉
    We now program this concept to adapt slowly to jumps in the set values for speed or steering. Steering is adjusted on a basis of the already traveled “length of the way” (route is goal 😉 (imagine some easy measure there. Our normal cartesian measure of Pythagoras is probably correct, but to calculus heavy. Squaring and rooting around. Does it have a floating point module, the poor thing??? 😉

    Please report back, for you AndiJsnLn.hofma at the domain 9ox.net, if you succeeded, because we have some dustiy NXT in school as well, just tell me where you are and got stuck.
    Since we use our own curve block anyways, it will be fine both with NXT and EV3, only bluetooth will not do with NXT, and no sensor feedback in EV3. Lego pushing us away from NXT, sigh. It boots so damn fast. Has no one at lego heard of linux and fast boot modes for EV3?

    NXT-Users: Do you have rechargeable batteries? After long frustrating sorting charging-discharging sessions with supermarket rechargeables of low quality I dare to recommend.
    If you’re fed up with old LiIons, just use eneloop NiMh batteries. 1,9EUR for 1 Mignon is OK. D: akku-onlinehandel.
    With BC-700 or successors (BC-900 etc. and similars) you can get the cheapest charger with discharge cycle to measure capacity and do refresh of cells. 18EUR up.

    I have 1,9Ah with all cells, bought some 100 (lower estimate), starting back at 2008, only 2 mistreated ones (<1V one time to often is not nice for NiMh) gave way to 1,6Ah.
    They can keep 75% Charge after 4years storage. At room temp.
    (I will develop a foil circuit for in-place-charging-and-discharging control of 6NiMh. Other time in the year. No more changing of cells. Reading of Ah remaining capacity of each cell 😉

    Yours

    Andish

  89. Andish

    Hi JsnLn !
    I just got hold of a NXT brick and tested.

    For me, edu EV3 and NXT with firmware 1.31, it works well.
    The steering wheel block even tries to go straight in the usual not-to-precice way, so blocking one wheel the NXT stops the other…

    The tank move block doesn’t. It keeps moving the free wheel if you block the other.

    So all fine, one might say.

    If you still like to try the circle follower, I would be interested to hear from you.

    I right now have no installation of the EV3 non-edu free version. Could it be it shows the error there while edu works fine???

    Which firmware does your NXT have?

    Andish

  90. Dana

    I have 3 questions for someone.
    1. I THINK that a NXT module will talk to another NXT. It looks like it in the manual. Will the EV3 and the NXT modules talk together? I have an NXT and am thinking of trying a EV3 and may want to daisy chain to get more inputs and outputs
    2. I just tried to download the latest software to talk to the NXT and my computer says it is not compatible with my software (Windows 8.2 I think). Is there a later version?
    3. Has anyone interfaced either of the Lego bricks to a PLC, say a A-B micrologix 1000?

    Thanks,

  91. Dan

    Can anyone give an opinion on whether it’s worth upgrading just my NXT to an EV3? I can get the brick on eBay for $130, and I already own the first two gen Mindstorms, so I have plenty of regular bricks and the motors and sensors, etc.

    I use Android so the NXT should be fine with BT and remote apps (though I haven’t tested). I’m wondering if there is a “killer app” that would make it worth the price to buy just an EV3 brick and maybe a 4th motor.

  92. bebox

    hi, thanks for this.

    then if i understand, my nxt brick is dead , i can buy an ev3 brick and use it with my motors and sensors ?

  93. JR

    Our church is doing space challenge competition and we were giving the NXT with the space challenge kit to practice on but everything I find on line they are using the EV3 and we are having a difficult time with hardware hook ups. So question is will the NXT even work with the space challenge?

    1. Laurens

      I don’t have the space challenge kit, but it appears that it includes a series of mechanical devices that must be moved or manipulated by the robot. This is similar, in a way, to First LEGO League competitions. NXT robots should work fine for most purposes.

  94. Chris

    I have 12 Robotics Invention System 2.0 kits. Will the parts/sensors work with a new EV3 kit? If not, how do I get them running? The software is out of date.

    1. Laurens

      RCX components don’t work with the EV3 brick.

      To use RCX components with more modern software, you can use RobotC or Brixcc. Both are free.

  95. Nishen Menerapitiya

    Hi,
    How do I connect a normal sensor (one used in arduino and stuff…..) with my Lego mindstorms ev 3 and get sensor outputs. (I have a temperature sensor with 3 pins)

  96. Tracey

    Hi. Someone has offered a nxt 2.0 for sale in my neighborhood for around $80. My son is about to turn 8. He is very good with building legos, and has done a tiny bit of drag and drop programming. Do you think it would be frustrating to him at this age? I could still get it and he could use it more as he ages, or is it better to buy an Ev3 later?

  97. Gilles

    Hi Lauren,

    I’m trying to use the EV3 software to program the NXT brick but it doesn’t accept the program that I’m trying to load. My program works on the EV3 but will not work on the NXT. Do I need to format the NXT or do something else to make the program compatible and run?

  98. tania

    I have imported hi technic color sensor to the EV3 software (from the hi- technic site ) and plugged the htcolor sensor to my ev3.

    I could see the numbers of detected colors on the brick’s port view, but not on the Ev3 (education )software port view .

    Moreover, even if a program with color detection could run successfully, there was a problem with the brick.
    The processor of the brick stayed idle since then and I had to put out the battery in order to end the process. I also tried other programs with htcolor sensor block and the same happened.

    What is the problem? And what can I do in order to use the htcolor sensor?

  99. Sandra

    So, my 18 year old was given Mindstorms NXT some years ago which has been wonderfully educational. After a break he has come back to it and has asked for a gyro sensor. Despite Lego website saying the EV3 is backwards compatible I’ve been told that the new sensors won’t work with the NXT set. So I want to know are old gyro sensors still available to buy and if so from where? Also thinking ahead what would be best way of upgrading his set or will he need to start from scratch again? Many thanks

  100. Ibrahim

    Thanks, Laurens, for this very helpful article. I have a large technic and NXT collection already – if I buy an ev3 brick on its own, will I have everything I need to get started? Ideally I would like to program in a text based language.

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