Hey friends!!
I’ve made a new external climate component to replace my Actron Controls B812(RT) air conditioner wall controller! It’s a WSHP (water-source heat pump) unit with an LE85R3 relay board.
The B812 communicates over a 2-wire bus using a custom pulse-distance protocol that
hadn’t been documented publicly before, so this repo includes the full reverse-engineered
protocol docs alongside the component.
What it gives you:
- Climate entity with cool / heat / heat-cool / fan-only modes and fan speed control
- Soft thermostat with hysteresis, auto-mode deadband, and compressor protection
- Diagnostic sensors (compressor state, protection timers, reversing valve, etc.)
- 2-zone damper switches with interlock logic
- Tested on ESP32-C3 with esp-idf; native C++ test suite included
→ GitHub: ddoodm/esphome-actron-b812
If you have a B812, B812RT, B512CW, LE612CW, LE75CW wall controller or an LE85/LE85R3
relay board and want to try it, I’d love to hear if it works for you!
Minimal example
# Signal to transmit over the PWR line
remote_transmitter:
id: ac_tx
pin: GPIO5
carrier_duty_percent: 100%
# Any temp sensor will work!
sensor:
- platform: homeassistant
id: room_temp
entity_id: sensor.room_temperature
# New climate component
climate:
- platform: actron_b812
name: "Aircon"
transmitter_id: ac_tx
temperature_sensor_id: room_temp