LEGO Mindstorms motor control board for Raspberry Pi [159010|150597]

This board combines the force of the Raspberry Pi with the mechanical force of powerful LEGO Mindstorms motors. Four LEGO EV3 servo motors can be connected, with PWM speed control for two of them and direction control for all four. LEGO EV3 motors have built-in optical encoders that generate pulses when a motor rotates.

The LEGO Mindstorms motor control board for Raspberry Pi combines the force of the Raspberry Pi with the mechanical force of powerful LEGO Mindstorms motors. Four LEGO EV3 servo motors can be connected, with PWM speed control for two of them and direction control for all four.

LEGO EV3 motors have built-in optical encoders that generate pulses when a motor rotates. This feedback signal can be used to measure the speed and position of the motor’s axis, allowing control within one degree of accuracy.

The LEGO Mindstorms motor control board for Raspberry Pi has 16 digital I/Os for all kinds of –not only LEGO- sensors and actuators, connected to the RPi’s I2C bus via two MCP3008 I/O-expanders. The Raspberry Pi can add keyboard, mouse, camera, WiFi, Bluetooth, Ethernet, display etc. to your design, and of course more RPi modules be combined to allow more complex control in your LEGO projects.

The board is 9 VDC powered, either by a battery pack or mains powered supply. It has an efficient on-board LM2956 5 VDC converter for powering the Raspberry Pi. It has a stackable 40-pin socket for the connection to the Raspberry Pi, and this also allows additional HAT-boards to be stacked on the RPi.

Your LEGO project can be programmed in any programming language available for the Raspberry Pi like C or Python, the latter supported by the library rpirobot.lib. There are some example Python scripts available that demonstrate the use of the board’s I/Os and control of LEGO EV3 servo motors.

This software from the book Raspberry Pi – Explore the RPi in 45 Electronics Projects can be used with this board.

Project Elements

159010-schematics.jpg (JPG, 223.4 KB)

159010 copper bottom V2.1.pdf (PDF)

159010 copper top V2.1.pdf (PDF)

159010 silk screen top V2.1.pdf (PDF)

159010_lego_rpi_examples_and_lib.zip (ZIP)

BOM 159010 LEGO Raspberry Pi V2.zip (ZIP)

Software, videos & guides (IDES)

https://youtu.be/DDuQadggvD4

Discussion (6 comments)

Sebastian Heierhoff 6 years ago

Hi Lucky,
as the board is no longer for sale, would it be possible to upload the Eagle/ Gerber files?
Regards,
Sebastian

0 Comment(s)

Arturo Garcia 6 years ago

Good day,

I would like to know if this complement works with all the models of Raspberry Pi, focusing specifically in if it works with the latest model (Raspberry Pi 3)? or was it designed for another model of Raspberry Pi

Regards,

Arturo

ElektorLabs 5 years ago

This product has been discontinued, sorry.

hussam almuayad 5 years ago

Is the Lego Control Board going be available soon or at any point? Or is it retired for good ?

Lucky 6 years ago

The board doesn't use any special I/O or features of the Raspberry Pi, it will work.

Regards,
Luc

3 Comment(s)

JohnHind 8 years ago

Reading the article in the magazine I became quite sceptical that the method used for processing the motor tacho signal would be reliable. Perusal of the Lego site reveals that the pulse rate of the tacho signal could be up to 1500/s. Each tacho is connected directly to a Pi GPIO and processed by in a sampling loop written in Python. Can this really keep up especially if the Pi is heavily loaded with, say, vision processing? Furthermore, it would be useful to be able to measure the pulse width accurately to get motor speed, which would likely be impossible due to unpredictable latency.

Might this be a case for biting the bullet and using a microcontroller? That could track the four tacho signals with the assistence of hardware counters or at least interrupts. Having got a microcontroller in there, it could also provide PWM for all four motors and handle the sensor inputs, the whole lot requiring just one serial link to the Pi.

sean om 6 years ago

From what I have read, the lego intelligent brick uses an armv9 processor.

1 Comment(s)

Dominik Tröster 8 years ago

When using a voltage regulator, make sure by design that the regulator will _never_ have to deal with a reverse current situation. When power is removed, internal capacitors or selfs, motors may still have energy stored. This energy may force its way through the regulator, maybe destructively. A simple DUS (Diode Universal Silicon) from IC1.Pin2 ->| IC1.Pin1 will let the electrons pass, just in case.
Best, Dominik T

0 Comment(s)

tono 8 years ago

Dank voor deze service. Ben zeker geintresseerd in de kit. Hou het in de gaten.
Ben gebruiker van de "Colinbus freesmachine" en kijk of de PCB daadop te maken is.

gr. Ton O

wolletje 8 years ago

hey Ton,

heb ook een Colinbus cnc. Is het gelukt?

prettige feestdagen en groet,

/Henk
henk@can-west.nl

1 Comment(s)

tono 9 years ago

Lucky,
Zijn er ook Eagle files van dit project beschikbaar. Het is voor mij niet eenvoudig om van de PDF files een PCB te maken.

gr, Ton O

DanBurkhalter 8 years ago

This project could easily be turned into a PIIOX-Module (see PIIOX project). Giving the possibility to add even more than 4 actuators to your project.