Firmware

After Wi-Fi setup, each ESPresense node uses MQTT in two directions.

Firmware Writes

Firmware publishes node state and BLE observations:

• espresense/rooms/<room>/status for online or offline availability
• espresense/rooms/<room>/telemetry for node health and configuration telemetry
• espresense/devices/<device_id> for detected BLE device updates

Firmware Reads

Firmware subscribes to configuration and command topics:

• espresense/rooms/<room>/+/set for per-node setting updates
• espresense/rooms/*/+/set for fleet-wide setting updates

This is how nodes receive runtime config such as max_distance, include, exclude, auto_update, and LED commands.

For the full topic reference and command examples, see MQTT Overview.