I am toying with the build hat with the intent to write a rust crate for it rather than using python. I got the basic right by uploading the firmware and signature and have a small REPL loop to toy with the interface and now trying to make sense of all I see.

Currently focusing on the light sensor. In all modes I see, they state SI = TYPE. What does SI even means ? And PCT ? Especially given that the min max reported have both PCT, SI and RAW ( so what does M2 AMBI SI = PCT even means ? )

Is there a finite list of type ? So far I encountered IDX, PCT, RAW, DEG, CAL and MIN.

Next question is how combo works ? When the sensor report C0: M0+M1+M5+M6, is it like a shortcut to ask the sensor to spill all mode ? Is it related to the combi command ?

For the 3x3 light matrix. how to do know the write1 byte header value ? The example always goes select X ; write CX p.... switching mode also reset the light matrix state, so how does the fade animation of mode 3 can work ?

And last for now, Is the firmware open source ? and what is the signature for ?

Thanks