Some updates:
I asked for a copy of the firmware, and they delivered!: https://github.com/m5stack/M5UnitKMeter_Firmware
- Short to Ground/VCC status > turns out all 32 bits is actually sent over i2c, so this is fully accessible. I was able to combine the first 4 bytes and then use code from a standard MAX31855 library to parse out all the info. (I'm builiding out an ESPHome component)
- Details about flashing firmware onto KMeter (note, I just soldered on a header and used platformio to flash the project as that was easier for me than figuring out the i2c transfer method that is also available)
- Ability to set address > it looks like with the
CMD_REG_ACCESScommand, you can have it assign a new address (I may just flash a custom firmware rather than figuring this out)