RGB LED

LIA’s status indicator is a full RGB LED, in four places on the board wired in parallel per channel (see Microcontroller for the pinout) — driving a channel lights all four at once, for visibility from any angle once the tracker is mounted on a collar. See Development History for a manufacturing note that currently limits the assembled units to the RED channel only.

Driving the LED

The RED channel is driven directly from the ESP32-S3 (Lred, GPIO40) via PWM, so brightness is adjustable, not just on/off. It’s active-high — the channel lights when the pin is driven high, confirmed against real hardware (an earlier assumption that it was common-anode/active-low, matching a datasheet guess rather than the actual board, was corrected after a real-hardware test showed the LED behaving the opposite way of what the code intended). The GREEN (Lgreen, GPIO41) and BLUE (Lblue, GPIO42) channels share the same wiring pattern.

Status behaviour

Continuous (BMS switch HIGH) mode: solid RED by default.
Sleep-cycle (BMS switch LOW) mode: off by default.
Manual override: send LED ON / LED OFF as a direct message to the device (see Meshtastic Configuration) to force it either way, overriding the automatic BMS-driven behaviour above for the rest of that boot. There’s no “back to automatic” command — the next sleep-cycle wake (a full reboot) resets to automatic control.