Raspberry Pi Forums

Is there any documentation on the actual i2c protocol that the AVR MCU on the Sense HAT uses? I couldn't find the firmware of the AVR that drives the LED matrix.
I'm trying to use the SenseHAT with another microcontroller, and with software emulated i2c on the Pi.

The SenseHAT code at: https://github.com/RPi-Distro/python-sense-hat doesn't access any I2C devices. The pixels are set up as a 64 pixel RGB565 frame buffer (how that's driven by the RPi is not documented).

There's docs at: https://www.raspberrypi.org/documentati ... /README.md

The idea is to talk to the device directly rather than through the linux driver.

Firmware source is here:
https://github.com/raspberrypi/rpi-sense

ShiftPlusOne wrote: The idea is to talk to the device directly rather than through the linux driver.

Firmware source is here:
https://github.com/raspberrypi/rpi-sense

DougieLawson wrote: The SenseHAT code at: https://github.com/RPi-Distro/python-sense-hat doesn't access any I2C devices. The pixels are set up as a 64 pixel RGB565 frame buffer (how that's driven by the RPi is not documented).

There's docs at: https://www.raspberrypi.org/documentati ... /README.md

I had a look at the docs on github, and nothing is mentioned about the I2C protocol the AVR uses. The firmware for the AVR isn't posted either.
Without any of this, it will be nearly impossible to use I2C commands to control the AVR (without using the standard driver), right?

EDIT:
https://github.com/raspberrypi/rpi-sens ... ter/main.c didn't seem to have much in it, but https://github.com/raspberrypi/rpi-sens ... pi-sense.S has assembly code. I'll need to have a closer look at it and see if it can be used.

It can definitely be used. The information is off the top of my head, so I can't give you the specifics, but there's really nothing tricky to it.Try i2cget and i2cset to write to the first few registers and the rest should be obvious.

I'm sure I've seen straight C libraries for talking to it, but the first one I found is a C# one: https://github.com/emmellsoft/RPi.Sense ... Support.cs

ShiftPlusOne wrote: ↑

Wed Mar 14, 2018 7:27 pm

It can definitely be used. The information is off the top of my head, so I can't give you the specifics, but there's really nothing tricky to it.Try i2cget and i2cset to write to the first few registers and the rest should be obvious.

I'm sure I've seen straight C libraries for talking to it, but the first one I found is a C# one: https://github.com/emmellsoft/RPi.Sense ... Support.cs

My application is based on Python, so I'll try using a Python i2c library.

https://github.com/4eMaLo/SenseHAT-Game-of-Life

I tried this out and it works perfectly!

Pinout and other info here, https://pinout.xyz/pinout/sense_hat# if that helps?