Miscellaneous stuff related to LEGO EV3 firmware

Reverse engineering the EV3 Color sensor

This contains reverse-engineered EV3 color sensor firmware source code. See ev3color for details.

EV3 sensor communication on a logic analyzer

This contains Sigrok/Pulseview recordings of the EV3 sensor communication. See ev3sensors for details.

EV3 protocol documentation/discussion

I have created an overview document describing the EV3 sensor protocol: link. The goal fo the document is to help with implementing custom sensors.

The document itself was originally written for the Open-Cube brick that is developed by the Department of Measurement of FEE CTU. However, the brick implements an unmodified EV3 protocol for keeping interoperability with the EV3 accessories.

LMS2012 formats

RBF (Robot Bytecode File)

Ev3dev already has a new assembler, see lmsasm.

RPF (Robot Program File)

This is just a templated RBF file (see template.lms)

Some sort of viewer might be useful. TODO

RGF (Robot Graphics File)

Done.

Small utility + library in Go

• /rgf - Go library for loading and saving RGF images.
• /lmsbmp - Go utility built around the rgf library. See the /lmsbmp/lmsbmp.md manpage for details.

ImageMagick way

You can also use ImageMagick to achieve the same thing. To convert as with --bt601=true, use the following command line:

convert source.png -crop WxH+X+Y -grayscale rec601luma -dither FloydSteinberg -remap pattern:gray50 destination.rgf

To convert the image like with --bt601=false, use the following command line:

convert source.png -crop WxH+X+Y -dither FloydSteinberg -remap pattern:gray50 destination.rgf

RSF (Robot Sound File)

Done.

This is the same format as the NXT RSO. FFmpeg already contains a muxer; SoX with RSO/RSF support can be found here.

One strange thing is that ADPCM playback on EV3 sounds really loud and distorted.

RDF (Robot Datalog File)

TODO (see cnvlog.c)

RAF (Robot Archive File)

This is just a tarball (see c_memory.c)

tar -czf archive.raf <files> # create
tar -xzf archive.raf # extract

RTF (Robot Text File)

This is a simple text file.

RCF (Robot Config File)

This is also a text file.

Typedata parser might be useful. TODO (see c_input.c)

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