The aim here is to set up the AVR-IoT with an MQTT Light using MQTT Discovery
The data pin for the NeoPixels must be connected to PC0 on the AVR-IoT board. As of now I have not figured out how to set number of NeoPixels from HA, so one must do that from the CLI.
Connect to the COM port of the AVR IoT and use the CLI to configure wifi, mqtt connection and credentials (9600 BAUD). Any terminal with serial support can be used, I like the MPLAB Data Visualizer a lot, at least if you want to output a lot of raw data from the MCU
FYI, this repo is a fork of avr-iot-mqtt-ha-sensor-node but since that repo is a fork of avr-iot-aws-sensor-node-mplab github did not allow me to fork it.