Mindstorms / SPIKE Prime / SPIKE Essential

This repository is a collection of useful information about the Lego Mindstorms Robot Inventor (51515), Lego SPIKE Prime (45678) and Lego SPIKE Essential (45345).

Hardware

Large Hub Hardware

This applies to both the SPIKE Prime and Mindstorms Robot Inventor large hubs.

Small Hub Hardware

This applies to the SPIKE Essential small hub.

Connecting to a hub

To connect to the hub you have two options, a micro USB cable or bluetooth. Both options create a serial connection between the hub and the computer. At the hub end of this serial connection is a micropython REPL (Read Evaluate Print Loop). You can use this REPL to run python commands just like you would in the python interpreter on your computer.

To connect on Linux you will normall use:

• /dev/ttyACM0 for USB connections.
• /dev/rfcomm0 for bluetooth connections.

Note: If you press and hold the left button then press the center button to power up the hub, it will startup bypassing the runtime on the hub.

I have found bluetooth on linux to be not that reliable and often have to follow this process:

bluetoothctl
> remove [ADDRESS]
> scan on
> connect [ADDRESS]
> pair [ADDRESS]
> trust [ADDRESS]

Then I can use rfcomm to create the bluetooth serial port /dev/rfcomm0:

sudo rfcomm connect hci0 [ADDRESS]

Directory Content

Controller

An attempt to create an application that can communicate with a hub to allow for remote control / sending of scripts / sensor logging without needing any of the LEGO apps.

Decompiler

This is a disassembler/decompiler that uses the mpy-tool from the micropython repository to disassemble mpy files from the hub filesystem.

Filesystem

Dumps of the micropython filesystem on the Lego hub using rshell.

# Install the rshell program if you do not already have it.
# pip3 install rshell

# Add udev rules for the hubs, and restart udev.
# cp ./filesystem/99-lego.rules /etc/udev/rules.d/99-lego.rules

rshell
> connect serial /dev/ttyACM0 115200
> rsync -a /pyboard ~/filesystem

Long version numbers are from running the help(hub) command on the board. Short versions numbers are from the version.py files where available.

SPIKE Prime

SPIKE Essential

Mindstorms Robot Inventor

Firmware

Dumps of the firmware on the Lego hub using the micropython REPL.

The lines below will output a number of bytes of the firmware starting at the provided location, or false if past the end.

import firmware
firmware.flash_read(BYTE_NUMBER)

The first versions of the firmware on the device do not have the firmware library. To dump these you have to use the DFU tool after booting the device into DFU mode.

To boot the device into DFU mode:

1. Turn the hub off and disconnect the USB wire from your computer.
2. Hold down the bluetooth button and plug in the USB wire to your computer.
3. Keep holding the bluetooth button until it starts flashing in a cycle (pink-green-blue-off).
4. The hub is now in DFU mode.
5. The dfu-util program can be used to extract the firmware, see the script below.

# Install the dfu-util program if you do not already have it.
# sudo apt-get install dfu-util

# List the connected devices, this should show the hub is connected.
sudo dfu-util --list

# Read the firmware.
sudo dfu-util --alt 0 --dfuse-address 0x08000000:1048576 --upload ~/firmware.bin

# Take ownership of the file created by the dfu-util program.
sudo chown $(whoami) ~/firmware.bin

# Remove the first 0x8000 bytes, as these are before the firmware starts.
fallocate -c -o 0 -l 32768 ~/firmware.bin

# Remove the trailing bytes that have the value 0xFF, as these are unnecessary.
sed -i '$ s/\xFF*$//' ~/firmware.bin

# Rename the firmware to the md5 hash of itself.
mv ~/firmware.bin ~/$(md5sum ~/firmware.bin | awk '{ print $1 }').bin

Long version numbers are from running the help(hub) command on the board. Short versions numbers are from the version.py files where available.

SPIKE Prime

SPIKE Essential

Mindstorms Robot Inventor

Simulator

A recreation of the spike prime hardware using python to allow testing and debugging python scripts on a PC.

The aim is to create a script to dump the functions of the real hardware and then mock them to allow local development.

Currently there is two main scripts one to simulate running micropython scripts on a hub and one to push micropython scripts to a real connected hub. The simulator uses a mocked implementation of the micropython modules available on the phyical hub that redirect actions to the simulator gui.

Specifications

Specification pdfs for internal parts of the Lego components.

SPIKE Prime and Mindstorms Robot Inventor

SPIKE Essential

License

Where documents, code, graphics, binary or any other files have been created by me they are licensed under the MIT license. Other files that have been pulled from the firmware or filesystem of LEGO products remain licensed by LEGO.

The MIT License

Copyright (c) 2020 Geoffrey Daniels. http://gpdaniels.com/

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. .