ThoxMesh-Head-C6

The ESP32-C6 half of ThoxAir. ThoxAir is a dual-chip device: the RV1103 runs the conversational model (Thox-ai/ThoxAir-16M-role, llama.cpp armv7-neon), and the XIAO ESP32-C6 is the wireless coprocessor — Wi-Fi 6, BT 5.3, Zigbee, Thread/802.15.4, Matter.

This is the triage head. The C6 sees every radio and sensor event before the RV1103 does; waking a 16M LLM for each Zigbee attribute report would be absurd, so this model classifies the event and escalates only what needs language.

format	int8 TFLite (full quant, int8 in and out)
size	9,512 bytes (budget was 256 KB — 27× headroom)
accuracy	int8 0.9647 vs float32 0.9645
runtime	TFLite-Micro / LiteRT-Micro

Quantisation cost nothing, which is worth stating because a clean float model collapsing under int8 is the classic TFLM surprise.

Classes

ignore · local_ack · wake_word · smarthome_command · sensor_alert · security_event · network_event · power_event

Only wake_word, smarthome_command, sensor_alert and security_event normally escalate to the RV1103.

Feature contract — firmware must match exactly

32 float32 features normalised to ~[0,1]. A wrong layout does not error, it returns confident nonsense, so this is the interface:

idx	meaning
0–5	transport one-hot: thread, zigbee, matter, wifi, ble, none
6–13	cluster one-hot: onoff, level, occupancy, contact, temp, humidity, energy, alarm
14–21	value, delta, rssi, battery, hour, is_night, repeat_rate, link_quality
22–29	8 log-mel band energies from the mic frontend
30–31	audio rms, zero-crossing rate

Full names and the input quantisation scale/zero-point are in meta.json.

This model does not consume raw PCM. Bands 22–31 come from the firmware's existing mic frontend; the log-mel/MFCC frontend stays in firmware. What this head adds is fusing the audio summary with radio context.

Known limitation — synthetic data

Trained on synthetic per-class distributions. No real device captures were available. The weights are real and the class shapes are calibrated, but it has no real-world priors. It wants a pass over real Matter/Thread/Zigbee captures before being trusted for anything safety-adjacent — particularly security_event.

Ship-first: not measured on C6 silicon.