HeishaMon Firmware

Overview

HeishaMon is the official firmware for the HeishaMon Communication PCB, turning an ESP8266 or ESP32-S3 into a full-featured MQTT gateway for Panasonic Aquarea heat pumps (H, J, K, L, and M series).

Features

• MQTT Gateway: Publishes all heat pump telemetry to an MQTT broker and accepts commands for full local control
• HTTP JSON API: Serves real-time data at /json endpoint for direct integration
• Built-in Rules Engine: Create local automation rules that run directly on the device without requiring an external home automation platform
• 1-Wire DS18B20 Support: Connect temperature sensors for monitoring buffer tanks, flow/return pipes, and outdoor temperature
• S0 Energy Metering: Dual kWh pulse meter inputs for tracking energy consumption and COP calculations
• OpenTherm Support: Connect an OpenTherm thermostat for room temperature-based control (on compatible PCB versions)
• Onboard Relay: Direct relay control on the large board version
• MQTT TLS/SSL: Encrypted MQTT connections (ESP32-S3 version)
• Web Configuration: Browser-based setup wizard via temporary WiFi hotspot
• OTA Updates: Firmware updates via the web interface

Supported Hardware

• ESP8266 (Wemos D1 mini or compatible, 4MB+ flash)
• ESP32-S3 (newer large HeishaMon PCB)

Integrations

The firmware works with any MQTT-compatible platform including Home Assistant, openHAB, Domoticz, ioBroker, and Node-RED.

Community

The project has 357+ stars on GitHub and an active community on Slack. With over 1,600 commits, it is the most mature open-source Panasonic heat pump integration available.