Questions about programming the various LEGO programmable bricks, including Mindstorms (EV3, NXT, and RCX), Wedo and Scout, in either the provided languages and editors, or more advanced languages.

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36
votes
6answers
36k views

Is there any other way to program the Lego Mindstorms NXT other than the provided software?

I'm curious to know if there is any way to program the NXT other than the provided software. I don't necessarily have any issue with the software. Does the program created by the software translate ...
19
votes
4answers
8k views

How to calibrate NXT motors to travel the same distance?

The motors included with the NXT are not all created equal - when given the same input power level, they do not always go the same distance or turn at the same rate. I measured this by creating a ...
17
votes
4answers
6k views

Can you program Lego Mindstorms with the Scratch programming language?

My child is learning programming using Scratch in school. Can she program her Mindstorms using Scratch?
15
votes
1answer
1k views

Can I write programs for the LEGO RCX 2.0 in Java/C++?

Is there a library which makes it possible to write LEGO Mindstorms programs for RCX 2.0 in Java or C++? With the LEGO software it takes so much time to write good programs.
11
votes
4answers
4k views

Can I control 2 NXT bricks from a computer using bluetooth at the same time?

I am thinking about starting a project involving controlling the movement of a mindstorms robot depending on some input from a Kinect device; however the robot will require at least 6 motors. I have ...
11
votes
2answers
655 views

Why does this program work in LabView when targeted to computer but not to NXT?

I have a program written in Labview for my LEGO Mindstorms NXT 2.0. When the target is set to the computer, the program works just fine. However, when I set the target to the NXT, the program doesn't ...
10
votes
2answers
1k views

Can we program Nxt2 in C++ under Visual studio 2010?

I'd like to know if it is possible to develop C++ software for NXT2 using Visual Studio 2010 as IDE. I know there are small online projects for NXT but I can't find nothing about NXT2.... Any ...
10
votes
4answers
5k views

How to make Mindstorms respond differently, depending on which sensor is triggered?

I am new to Mindstorms (but in my day job I am a programmer). I want to make my robot do one thing if the touch sensor on port 1 is pressed, and do something different if the touch sensor on port 2 ...
9
votes
1answer
295 views

NXC Saturation algorithm for limiting motors?

What is a good algorithm in NXC for control saturation? I want to make sure my motors don't turn past a certain angle, or they will break the model. I could do something like: if (angle > 45) ...
9
votes
0answers
254 views

PosRegEnable - How to change motor parameters?

I want to set PID parameters for a faster 'attack' when using PosRegEnablePID() on a motor. I am compiling with nbc/nxc 1.2.1 r4 mac osx fatbinary using -Z2 and -EF flags. But the compiler says: # ...
8
votes
1answer
443 views

Is it possible to display large text on an NXT using LabVIEW?

In RoboLab and using RobotC, it's possible to write LARGE text to the screen of the NXT. In RoboLab, this can be done by just typing [\big] at the beginning of a string constant which is wired into a ...
7
votes
1answer
271 views

NXT motor power accuracy

When turning the motors, how precise is the speed parameter? I am programming in the NXC language (standard firmware) and wishing to know how many decimal points will be taken, if any, and whether the ...
7
votes
1answer
563 views

How can I power an NXT motor without the NXT brick?

I know almost nothing about robotics, so I was wondering how can I power the nxt motor without using the nxt brick, and how can I send signals to it?
7
votes
1answer
629 views

NXT brick output ports not working properly

My NXT brick will not let motors run. When I download a program the motor will move forward and backward and then stop - sort of a wiggle. Another motor will not work at all. This happens for all ...
7
votes
1answer
3k views

Mindstorms 2.0 can't download to NXT brick with error 142023

Using Mindstorms education 2.0 on a Windows 7 computer I can't seem to get the program to see the NXT via USB or bluetooth dongle. When connected by USB nothing appears in the NXT window with device ...
7
votes
3answers
4k views

How to program two NXT motors to run at the same time?

I'm working on a project with multiple axis of movement… trying to get two motors to run at the same time in order to achieve a mix of two!
7
votes
1answer
255 views

Is there a way to change the Lego NXT sensor polling frequency?

I am using LEGO NXT 2.0 with the native NXT flowchart-style programming environment, I would love to be able to poll the sensors more frequently. (In particular, it seems that the light sensor is ...
6
votes
2answers
148 views

Making an ATM with an EV3

I am building an ATM using my LEGO Mindstorms EV3, but I ran across a problem. The problem is that I want to be able to input the amount of money that I want to get out of the ATM but I can only have ...
6
votes
2answers
436 views

Ultrasonic problems with the red and blue balls?

I'm still new to NXT, I try to make the robot locate a ball using the ultrasonic sensor, while there I should be in a square area marked by white color. How can I make the robot locate the object (by ...
6
votes
1answer
578 views

Pass sensor or motor port number as a parameter

I want to create a block for one light sensor or one motor separately. Is it possible to give the number of the port as a parameter to a sensor or motor block via data wire? In NXT-G it was possible.
6
votes
1answer
195 views

Gunner bot programing

I just build the RCX Gunner Bot using the instructions from this web site. I had to build something different to the one we built in the class, I added a touch sensor and light sensor, so the bot ...
6
votes
1answer
654 views

Program a full rotation of a NXT motor in X seconds

I'm interested in mimicking the functionality of the Arqball Spin, at $60 it isn't cheap so I'd like to make the most out of my Mindstorms parts. I'd like to use NXT-G to program a motor to rotate ...
6
votes
2answers
176 views

Mindstorms start block is missing

the start block is missing on my mindstorms NXT 2.0 programming space. i cannot run any program without it. i have tried, restarting the programming window, placing a block and even just undoing to ...
6
votes
2answers
2k views

How to control a RCX from a Mindstorms NXT

I have both an RCX and an NXT. I would like to control the RCX brick from the NXT (and possibly communicate back to to the NXT from the RCX). I would like to avoid purchasing the Mindsensors RCX to ...
6
votes
1answer
1k views

How can I rotate an EV3 motor an exact number of degrees using RobotC?

I'm trying to rotate the motor of an EV3 by an angle of 50°. I can't. How I can rotate a NXT/EV3 motor by a given angle using RobotC?
6
votes
1answer
223 views

EV3 RMIregulatedMotor Regulation Problems

I have problem with regulation of the motor when I control EV3 with Bluetooth. Here is the code: RemoteEV3 ev3 = new RemoteEV3("10.0.1.1"); ev3.setDefault(); RMIRegulatedMotor leftMotor = ...
5
votes
3answers
755 views

Is there a microphone that works with Mindstorms EV3?

I'm planning to program my EV3 robot to do voice chat over VOIP using ev3dev and a Debian program. Is this possible? Are there microphones known to work with EV3, and has anyone had experience using ...
5
votes
1answer
612 views

What can cause programmed NXT 2.0 motors to misfunction when small resistance is applied?

I have robot built per the Alligator tutorial included with Mindstorms NXT 2.0. Everything works correctly if I hold it off the ground and make sure there is no load on the two leg motors. However, if ...
5
votes
3answers
3k views

Is it possible to edit a my block input parameter value?

I have created my blocks but want to change the input parameter to a negative. Is this possible or must all the myblocks be re-written?
5
votes
3answers
2k views

In lego mindstorm EV3, can you make the individual programs in a project into functions which can be used in the other programs?

The bit where you program what the robot does using your computer. I'm making a project and I can't fit it all onto the screen, so if you can't do functions, is there any way to zoom out of the screen ...
5
votes
1answer
2k views

Can you program an RCX using the Mindstorms NXT 2.0 software?

I was asked to teach a robotics class and found several RCX bricks in storage. Can I use these bricks with the Mindstorms NXT 2.0 software? If not, what would be the software I would need to use the ...
5
votes
1answer
253 views

Set to run a program within another program using NXT-G

I'm using NXT-G to program my robot to do few tasks autonomously for so many possibilities. When using C programming, we can call a function from different file into the main program. So, I wonder if ...
5
votes
1answer
480 views

How to build an automatic Lego train system?

I was wondering if anybody has ever tried using the IRLink NXT sensor to make an automated train system and if so, what kind of setup did you have to make it all work? I have been working on a train ...
5
votes
1answer
699 views

RobotC for RCX cannot find USB IR Tower

I have looked for similar question but found null. So here I am asking. I have Win7, a RobotC fo RCX and Mindstorms for RCX (both are old version, but available free). I borrowed an old LEGO kit ...
4
votes
2answers
79 views

Is there a time mechanism that can be added to an NXT program?

I wanted to create a system where an NXT block would be set into function at a certain time of day (maybe 5:00 and then 5:10 and so on). I would want the timing function to be embedded into the NXT ...
4
votes
3answers
2k views

EV3 Brick Error Symbols?

I am currently developing an EV3 robot that sorts colored technic beams. However, the brick will only run part of the program and then generate a strange error code on the brick's screen. The error ...
4
votes
3answers
3k views

API for Android or iOS connecting to EV3 by bluetooth

There is official API for Windows, WindowsPhone8 and WinRT https://legoev3.codeplex.com/ it lets you connect to EV3 brick and control it remotely from your WindowsPhone. Are there any libraries ...
4
votes
2answers
950 views

Is it possible to change the OS in the EV3 Mindstorm Brick

I'd like to know how to change the OS embedded into the EV3 mindstorm Brick ( list of it ). For example, would it be possible to replace the existing one by a linux release without losing any ...
4
votes
3answers
3k views

Invert motor block in EV3

New to EV3 so this should be simple. I would like my simple wheeled robot to go backwards. So I put two invert motor blocks, one for port B the other for port C followed by a move steering block. The ...
4
votes
1answer
677 views

can't send multiple commands to EV3 using Python

I want to use Python to send commands to an EV3 brick. In C++ things work as expected - for instance, this starts the motor on port A and then stops it after a while: #include <unistd.h> ...
4
votes
3answers
455 views

Holonomic robots using Mindstorms

I just got some Rotacaster wheels and want to try building a 3 wheeled Mindstorms omnibot (holonomic robot) and I'm looking for a practical (easy) discussion about writing a driving program. I've ...
4
votes
3answers
476 views

How can EV3 Gyro sensor drift be handled?

EV3 robots can use a Gyro sensor to determine the direction the robot is heading. The initial conditions are important. The sensor needs to be still and then the sensor reset. However, once in a ...
4
votes
1answer
1k views

Can I open my old NXT program files in the new EV3 software so I don't have to rewrite the entire program?

I would like to use or convert NXT-G 2.0 programs for use with the new EV3 software. Is there an easy way to convert them besides just building them from scratch in the EV3 environment?
4
votes
1answer
193 views

Setting priorities in LEGO NXT Programmer

For a sumo bot competition I made a robot that has a perfectly functioning ultrasonic senor. However, when I made a second branch on the program for a light sensor, I calibrated the light sensor and ...
4
votes
1answer
228 views

Custom EV3 Block: “Unable to compile…” (“string subsection”)

I am attempting to make a custom block according to the EV3 Block Developer kit (found here). I was able to create a simple block that returns the length of a string. This is what it looks like: (The ...
4
votes
2answers
361 views

How can I find the analog output of a color sensor?

Could anyone provide me with an image of the voltage output of an NXT or EV3 colorsensor. I would like to have the analog output if it's possible, and not the digital output.
4
votes
1answer
44 views

DNX on Lego Mindstorms

I am not familiar with ARM development but I am wondering would it be possible to compile DNX against Lego Mindstorms EV3 processor. I know there is some ARM support and even there are some builds ...
3
votes
3answers
162 views

Access WeDo on OS X from a real programming language

I'm trying to talk to the WeDo USB interface from Python or really any real programming language. I tried the clever WeDoMore library, but can't get it to bind the WeDo. I think this is because the ...
3
votes
1answer
114 views

How to minimize the impact of erroneous sensor readings?

A group including myself are using the Lego Mindstorm kit to design a robot that is going to compete in a school competition. However, the sensors aren't as reliable as we would like them to be, ...
3
votes
2answers
291 views

Have Multiple Inputs to Programming Block

Originally, I had a simple program to move until the robot hit a wall, then it reversed and turned and moved again, repeated to infinity. It works by turning the motors on, waiting for input from the ...