Questions tagged [ev3]

EV3 is the current generation of LEGO MINDSTORMS, released in 2013.

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1answer
1k views

Slow down the mindstorms EV3 motor so target position is not overshot

I have Debian jesse installed on a mindstorms EV3 and I'm using the ev3.lego library: https://github.com/topikachu/python-ev3 I want to be able to slow down the motor as it reaches its target ...
4
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1answer
481 views

What is the LEGO EV3 rpf file?

I read the LEGO Mindstorms EV3 Communication Developer Kit's document. I have a question in 4.2.1 (Start program “Demo” on EV3 brick) it is mentioned "The file-extension is "rpf" and NOT "rbf", so ...
3
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1answer
1k views

Can EV3-G MyBlocks be recursive?

Imagine I create a MyBlock called function1 from a line of blocks. Can I call that block from within itself? This is the program for the block recursiveTest. Will this block function properly?
0
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1answer
549 views

Installed EV3 software on Win 8 and it won't load

EV3 software used to work on my laptop. Now it does not load any more. When I double click on the LEGO Mindstorms icon. It starts the procedure of loading the software. Then it stuck there and won'...
6
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2answers
2k views

What are the differences between NiMH and Alkaline batteries for the EV3?

Currently I am using six rechargeable batteries for my Lego Mindstorms EV3. A few seconds after I start a motor the EV3 gives a notification that that the battery is low. I know that good batteries ...
2
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1answer
1k views

EV3 with NiMH batteries

Could I use 6 NiMH 1.2V batteries and keep pressed the small black circle in the battery compartment in order to adjust the battery gauge and low battery alarm?
6
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1answer
183 views

Colored balls detectable by EV3 color sensor

I'm looking for large balls in standard Lego colors that are detectable by the EV3 color scanner. So black, white, green, brown, yellow and blue and between 5 and 10 cm. I'm aware of the Duplo balls:...
0
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1answer
62 views

Mindstorms program - myblocks that work fine when run individually but when executed as part of a larger program, break

We have a line following myblock, which follows the line perfectly if it runs alone. However, if we include it as a block as part of a larger program, it goes haywire when it gets to that step and ...
3
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1answer
194 views

EV3 Rapt3r's head cable interfering with slithering

My Rapt3r is working great, except that the cable that goes from the head to the "Intelligent Brick" physically interferes with the slithering on the side on which it is plugged (port 4). Physically ...
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2answers
909 views

“Unable to compile” error code with LEGO EV3 Arm Robot Program

Does anyone know how to fix this error with my LEGO EV3 program? Unable to compile some documents for deployment: Program.ev3p: Use of a block which no longer exists. INI.ev3p: A My Block cannot ...
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3answers
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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
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2answers
3k views

Sort the program list on EV3

When uploading a project to the EV3 brick, is there a way to control the sorting order of the programs on the brick? E.g: Prog_1 Prog_2 Prog_3 ... When playing a robot match in FLL one often needs ...
4
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1answer
84 views

Why do two EV3 bricks have different power outputs?

I have two identical box designs with EV3 bricks. When I upload the same programs to both, one moves about twice as fast as the other. Is there a reason that this might be happening? Is there ...
2
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1answer
377 views

EV3 Installation failure on OSX El Capitan 10.11.3

Hi This is the first time I've tried to use EV3 software since upgrading to El Capitan. Before then, it worked perfectly. When I tried to launch the application a message pops up saying it has ...
2
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1answer
386 views

List of parts to buy for to “upgrade” existing Mindstorms NXT 1.0 to Mindstorms EV3 set?

Is there a list of parts available I need to buy to "upgrade" an existing Mindstorms NXT 1.0 (8527) set to a Mindstorms EV3 set?
4
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1answer
983 views

How to make Lego Mindstorms EV3 robot go in reverse when move steering input comes from proximity sensor

I saw an program on the Lego Education page which makes a Lego Mindstorms EV3 robot gradually slow down as it approaches a wall. The info from the proximity sensor is used as the direct wire input of ...
5
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2answers
6k views

Is the LEGO BOOST kit compatible with EV3 or PowerFunctions motors and sensors?

I'm curious if I can use my existing EV3 and/or PowerFunctions motors to extend the functionality of my LEGO BOOST set. Is this possible?
2
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3answers
2k views

Does the Mindstorms EV3 software work on macOS Sierra?

I guess this is a continuation of these two questions: Does the Mindstorms EV3 software run on OS X El Capitan? Is the LEGO Midstorms EV3 software compatible with OS X yosemite? macOS Sierra was ...
4
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1answer
236 views

Is code written for NXT bricks compatible with EV3 brick (for Johnny 5 building)?

My son is mad on the robot from Short Circuit (Johnny 5) and I want to build robots with him. We have a copy of Daniele Benedettelli's "Creating Cool Mindstorms NXT Robots" and I was planning to start ...
3
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1answer
3k views

How do I have an else in conjunction with an if statement with two conditions?

I can't find a way to emulate an AND statement in a switch statement: if (angle >= 10 and angle <= 30) ;// do smth else ; // this is what I want Until now, I just nested two if ...
4
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1answer
6k views

EV3 brick cannot connect my to computer

I can't connect my brick to my computer. It keeps saying it can't communicate with the brick. My brick has no firmware. My friend said to change the USB cable but it still doesn't work. I can't ...
4
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1answer
2k views

Is it possible to fix a broken EV3 Port?

I have an EV3 running RobotC version 4.55. The medium motor connected to Port A does not run, but if I connect it to another port (B,C,or D) it works. I tested it manually through the EV3 motor tab ...
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3answers
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How can I use multiple switch options in Lego Mindstorms EV3 software?

What I see is just a simple if/then/else. What I am looking for is to be able to add multiple options, more than yes/no. I use a motor as a switcher, so I rotate it to some position and measure its ...
5
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1answer
977 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 ...
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0answers
338 views

Is there an leJOS simulator for EV3?

I found this but this seems to be using their own library to control the EV3.
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1answer
761 views

Lego Mindstorms EV3: programming language recommendation

I am planning to build an autonomous car in LEGO Mindstorms that will use ultrasonic or infrared sensors and in the future also a camera for line tracking. Currently I construct my programs using the ...
0
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1answer
549 views

Does the Lego Mindstorms EV3 software work on macOS High Sierra?

Will there be issues with the software, or will it work properly on macOS High Sierra? My Mac: Retina MacBook Pro 13", Early 2015
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1answer
245 views

Why does my EV3 not have data logging in Brick App menu?

I recently purchased a 45544 Educator Mindstorms product. In working through tutorials. I am at section on data logging, but my Brick Apps menu stops at Brick Program. Data Logging is not on menu My ...
2
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1answer
222 views

EV3 motor control proportional to another motor when more than two motors

From what I understand, in EV3-g you can use "move steering" or "move tank" blocks to regulate two motors proportionally to each other as they have a built-in PID controller to do that. If one motor ...
6
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1answer
3k views

How do I export LEGO Mindstorms programs on the Chromebook

There is now a Chromebook app to program LEGO Mindstorms. I have multiple kids collaborating on programs for FIRST LEGO League. Can they share the program between their Chromebooks? I don't see a ...
4
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2answers
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How to connect two LEGO Bricks EV3 by USB using python

For some project, I have to use 7 motors with ev3 bricks. So I would like to connect 2 bricks using USB-USB link, and make them communicate, in python. But I don't know how to do that, I've tried ...
2
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1answer
273 views

EV3 switch block does not recognize text?

i am using file access to input variables into my programm. text file is something like this: a b c .. on each loop, program access file (using File Access block) and reads a new line "a" or "b" or "...
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1answer
2k views

pc program to receive data from EV3 via usb/bluetooth

I'm looking for a library to create a desktop program. It should receive a data from EV3 brick programmed by standard EV3 software. Currently I consider 2 approaches: 1. EV3 brick sends a bluetooth ...
2
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0answers
35 views

Is my EV3 controller bricked? [duplicate]

My EV3 controller seems to be 'stuck' in this state: Is the device operating properly? If not, is there a procedure that can unbrick the controller? Thank you
1
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1answer
600 views

How can I build a compact EV3 gearbox?

I'm building a sumo bot in EV3 and would like to have both 1:1 and 1:3 gear ratios, with the first being useful for general driving and the second more for pushing other robots. My problem is, I ...
5
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1answer
8k views

Naming a program in EV3 software?

I have figured out how name a project but cannot figure out how to rename a program.
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0answers
530 views

EV3 connection problem via USB on Windows 8.1

I am using LEGO EV3 on windows 8.1 eclipse Neon. When I try to launch the class as a LeJos application I get this error. IP address is /10.0.1.1 Creating the jar file or uploading the program failed ...
4
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1answer
2k views

How to get double the speed from 2 regulated EV3 motors?

So I've noticed that if I connect two EV3 motors to one another (with gears), I still get exactly the same maximum speed as if I had a single motor. So, my question: how can I get twice the power/...
11
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1answer
270 views

Are there any benefits to using PF motors instead of EV3 ones?

Can someone explain to me the key differences between PF motors and EV3 ones? I understand that EV3 motors are 'regulated', presumably meaning that you can control their rotational speed depending on ...
2
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1answer
3k views

Is it possible to connect EV3 and NXT bricks like master/slave configuration via bluetooth?

Can I make a Bluetooth connection between LEGO EV3 bricks and LEGO NXT bricks? and If it is possible how to handle the software to make a chain between them?
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4answers
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Every time Robot is launched (without changing the code) it is not following the exact path

I'm working on FLL mission and every time our team launches the robot (without changing the program, and we are making sure that it is starting from same location every time) it is not following the ...
5
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2answers
1k views

How can I attach a Technic Linear Actuator to a EV3 Medium Motor?

I'm pretty new to serious LEGO building (never got past very blocky houses as a kid but got into Technic a couple of months ago) and need to connect a Technic large linear actuator (61927) to a ...
2
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1answer
411 views

EV3 Wired Brick to Brick communication

I'm currently working on a project for my intro to engineering class. As it stands now, one brick is running a LabView program to intake data from a 'barcode' and another brick runs a Matlab program ...
3
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1answer
1k views

How do you open a logfile (.rdf) downloaded from an EV3 brick?

I have been logging data for a few sensors, and would like to import that data into Excel. What exactly do I need to do? I remember reading somewhere that LabView can export logging data (I have the ...
3
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3answers
2k views

My Blocks with return parameter

I have the retail EV3 kit and have created a function with in and out numeric parameters. While using the [in] params seem quite straight forward, it seems that I can only set the [out] param once. ...
7
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1answer
3k 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.
4
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1answer
105 views

Any way to track a light source in 1 dimension using one color sensor?

I would like to know if there is any workable way to use a single color sensor to track a light source in one axis of rotation? Would rotating the sensor back and forth within a few degrees, every ...
3
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2answers
4k views

Can't get EV3 to work with touch sensors

My FLL team just got a couple of EV3 sets and the kids were trying to program a simple switch that has the robot drive into a wall, back up, and turn right once the touch sensor in the front is ...
0
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1answer
114 views

Bazooka blast ev3 Mindstorms using Python

I would like to shoot balls with the ev3 Lego robot. How can I code it using Python? Which components do I need for that and which function and motor use ?
3
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1answer
389 views

Mindstorms EV3 3D building instructions no longer working in Chrome

Lego Mindstorms EV3 building instructions in 3D (so that one can rotate the model around and stuff) are available. This used to work fine on my machine in Google Chrome. However, I can no longer get ...