# HeishaMon Communication PCB

> Open-source ESP-based communication PCB for local monitoring and control of Panasonic Aquarea heat pumps via MQTT and HTTP, with Home Assistant integration and S0 energy metering support.

## Quick Facts

- **Brand:** TheHogNL
- **Board Type:** communication-pcb
- **Price:** ~$20
- **Product Readiness:** diy-kit
- **CPU:** ESP8266EX
- **CPU Architecture:** Xtensa LX106
- **CPU Cores:** 1
- **RAM:** 80KB
- **Flash:** 4MB
- **USB:** USB-C
- **Power:** 5V USB-C or heat pump CN-CNT 5V
- **Operating Voltage:** 3.3V
- **Antenna:** Built-in PCB antenna

## Connectivity

- **Wifi:** 802.11 b/g/n
- **Ethernet:** 10/100 Mbps (W5500, large board only)

## Open Source

- **Firmware:** Yes
- **Schematics:** Yes
- **PCB Layout:** Yes
- **License:** GPL-3.0

## Compatible Firmware

heishamon, arduino, esphome

## Use Cases

- heat-pump-monitoring
- heat-pump-control
- energy-monitoring
- hvac-control
- home-automation
- smart-home

## Components

- **ESP8266EX** (mcu): Espressif ESP8266EX single-core Xtensa L106 WiFi SoC @ 80/160MHz with 802.11 b/g/n — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2F0a-esp8266ex_datasheet_en.pdf&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)
- **level-shifter** (voltage-regulator): 5V to 3.3V bidirectional level shifter for Panasonic heat pump UART communication — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.ti.com%2Flit%2Fds%2Fsymlink%2Ftxb0102.pdf&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)
- **DS18B20** (temperature-sensor): Supported external 1-Wire digital temperature sensors connected to GPIO4 — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fdatasheets.maximintegrated.com%2Fen%2Fds%2FDS18B20.pdf&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)
- **W5500** (ethernet-phy): WIZnet W5500 10/100 Mbps hardwired TCP/IP Ethernet controller via SPI (large board only) — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fdocs.wiznet.io%2Fimg%2Fproducts%2Fw5500%2FW5500_ds_v110e.pdf&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)

## Protocols

- **UART**: GPIO13 (TX), GPIO15 (RX)
- **1-Wire**: GPIO4
- **S0 Pulse**: GPIO12 (meter 1), GPIO14 (meter 2)
- **SPI**: W5500 Ethernet (large board)
- **MQTT**
- **HTTP**

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| GPIO2 | Debug LED | — | — |
| GPIO4 | 1-Wire (DS18B20 temperature sensors) | — | — |
| GPIO12 | S0 pulse meter input 1 | — | — |
| GPIO13 | UART TX to heat pump | — | — |
| GPIO14 | S0 pulse meter input 2 | — | — |
| GPIO15 | UART RX from heat pump | — | — |

## Available Software

- **[HeishaMon Web Dashboard](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FEgyras%2FHeishaMon&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)**
- **[Home Assistant Integration](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fkamaradclimber%2Fheishamon-homeassistant&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)**
- **[Node-RED Control Flow](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fedterbak%2FNodeRed_Heishamon_control&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)**

## Description

# HeishaMon Communication PCB

The HeishaMon Communication PCB is an open-source interface board designed for local monitoring and control of Panasonic Aquarea heat pumps (H, J, K, L, and M series). It eliminates the need for cloud connectivity by providing direct MQTT and HTTP API access to heat pump data, making it ideal for Home Assistant and other smart home platforms.

## How It Works

The board connects to the Panasonic heat pump's CN-CNT (indoor unit) or CN-NMODE (outdoor unit) connector using a standard serial UART interface at 9600 baud (8E1). A level shifter converts between the heat pump's 5V logic and the ESP's 3.3V levels. Once connected, the HeishaMon firmware reads all available heat pump parameters — temperatures, flow rates, operating modes, error codes, and energy consumption — and publishes them via MQTT topics.

## Two Board Variants

- **Small board** (ESP8266, Wemos D1 mini form factor): The original compact design with WiFi connectivity, 1-Wire temperature sensor support, and two S0 pulse meter inputs for energy monitoring. Powered via USB-C or directly from the heat pump's 5V supply.
- **Large board** (ESP32-S3): An expanded version adding optional W5500 Ethernet connectivity, two onboard 230V/5A relays for controlling external heating elements or pumps, and additional GPIO for peripherals.

## Key Features

- **Full heat pump telemetry**: Reads 200+ parameters from Panasonic Aquarea heat pumps including water temperatures, compressor frequency, COP, and error codes
- **MQTT integration**: Publishes all data to MQTT topics with configurable update intervals for seamless Home Assistant, Node-RED, or openHAB integration
- **HTTP API and web dashboard**: Built-in web interface for configuration, real-time monitoring, and firmware updates (OTA)
- **1-Wire temperature sensors**: Connect up to 15 DS18B20 sensors on GPIO4 for monitoring additional temperatures (buffer tanks, room sensors, outdoor)
- **S0 pulse energy metering**: Two S0 inputs (GPIO12, GPIO14) for connecting kWh pulse meters to track energy consumption
- **Optional Ethernet**: W5500 SPI Ethernet module support on the large board for wired network reliability
- **Optional relays**: Two 230V/5A relays on the large board for switching external devices based on heat pump state

## Community and Ecosystem

HeishaMon has a thriving community with thousands of active installations. Community contributions include:
- [Home Assistant integration](https://github.com/kamaradclimber/heishamon-homeassistant) with auto-discovery
- [Node-RED control flows](https://github.com/edterbak/NodeRed_Heishamon_control) for advanced automation
- ESPHome configuration for those preferring YAML-based setups
- Multiple 3D-printed enclosure designs on Thingiverse and Printables

## Compatibility

Supported Panasonic Aquarea heat pump series:
- **H-series** (2012+)
- **J-series** (2014+)
- **K-series** (2018+)
- **L-series** (2021+)
- **M-series** (2023+)

Both monoblock and split system configurations are supported.

## Where to Buy

- [Tindie](https://openhardware.directory/r?to=https%3A%2F%2Fwww.tindie.com%2Fproducts%2Fthehognl%2Fheishamon-communication-pcb%2F&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export) — $20.00

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.tindie.com%2Fproducts%2Fthehognl%2Fheishamon-communication-pcb%2F&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FEgyras%2FHeishaMon&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FEgyras%2FHeishaMon%2Fwiki&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)
- [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FEgyras%2FHeishaMon%2Ftree%2Fmaster%2FSchematics&ref=openhardware.directory&product=heishamon-communication-pcb&source=md-export)

## Tags

`heat-pump`, `panasonic-aquarea`, `hvac`, `mqtt`, `home-assistant`, `esp8266`, `esp32-s3`, `energy-monitoring`, `1-wire`, `s0-pulse`

## Images

![HeishaMon Communication PCB](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heishamon-communication-pcb/45814f38905d.jpg)
![HeishaMon Communication PCB](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heishamon-communication-pcb/d3bf6f1d1809.jpg)
![HeishaMon Communication PCB](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heishamon-communication-pcb/496f8504ce22.jpg)
![HeishaMon Communication PCB](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heishamon-communication-pcb/55e05f0a3471.jpg)
![HeishaMon Communication PCB](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heishamon-communication-pcb/b7786db908e3.png)
![HeishaMon Communication PCB](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heishamon-communication-pcb/35e53967130e.png)
![HeishaMon Communication PCB](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heishamon-communication-pcb/836c74fb44d7.jpg)
![HeishaMon Communication PCB](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heishamon-communication-pcb/e5c3a45f7975.png)

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