This project aims to control Poolex heatpump Jetline series. This kind of heatpump use UART protocol (no modbus, no TUYA) - at 9600 8N1, with 50 ms (52 with break condition).

This project is a personal project - dedicated to understand the communication flow through UART of a Poolex Jetline Selection 95 Pool heatpump and push all system informations to Home Assistant through MQTT.

This project runs on Wemos D1_mini at 160 MHZ, with Wifi interface, Remote Debugger through Telnet. It reads UART flow, identity patterns of messages, send sensors values to MQTT and receive commands through MQTT.

It reads :

• Water in and out temperature
• Gas temperature
• Coil temperature
• Exterior temperature
• Heatpump ON/OFF status

It doesn't YET send commands to heat pump.

Next step is sending commands to Poolex heat pump :

• Sending TARGET temperature
• Sending programs and Time programmations
• Start/Shutdown the pump
• Reading Error codes

• Wemos D1_Mini ESP8266
• MAX 485 UART interface
• Power supply converter from 12v to 5v
• Wifi bandwith where the heat pump is located
• Small IP67 box where to put the system

• From where I started : esp8266_poolstar repostory
• Understanding the different protocol : esp8266 fork from Cyril
• Python version
• Exploration thread on Heatpump using Modbus
• Reverse engineering of Hayward pump Forum Arduino
• Reverse of Poolex Dreamline pump Repository

I use C++ language, Arduino regular library, and PlatformIO development platform.

You need to have the full development environment of Platform IO for making this up.

I use the controller wiring to connect to the UART bus.

It's a four wire cable where :

• Green+Yellow : UART RX/TX
• Black+Red : Power supply 12v

I created a harness for making this system disconnectable.

By design, the quality of the connector are very poor. They fastly oxydize. I use DEUTSCH connectors, water proof and high quality designed.

For the first upload of the program, you will power this up from Micro USB of your computer.

Then, It will be powered from the Panel ( black/red +12v).

You'll need a converter from 12v to 5v with minimum of 2A.

5V power supply from the converter will supply the MAX485 (GND and vcc), and the ESP8266 (Wemos here) (5v and GND pin).

Heat pump panel has 4 wires.

Green and Yellow of the panel go to A and B of the MAX485

Yellow of the MAX485 goes to RTX of the ESP

Green of the MAX485 goes to RX of the ESP

DE/RE are linked together (you need to do the link), of the MAX485, and goes to pin2 as D4 of the ESP

I've struggled a lot to understand HOW to isolate messages from the UART bus.

Standard Arduino lib doesn't read break condition. Without break condition, it's like reading the matrix and understanding the pattern. I don't have time for that.

So I decided to find a way to isolate message even if I don't have the start or end position.

Reading a lot of documentation, I figured out it's possible to rely on reading timeout to isolated a frame reception. This allowed me to structure permanently the way I receive UART message.

Following that, time to decrypt messages.

This project is designed to speed up the exploration process.

You can :

• Update on the air (OTA) the Arduino
• Live debugging through TCP the program (Remote Debugger - this library is awesome)
• Adapt the UART communication framing parameter to adapt according your heatpump

For remote debugging :

> telnet IP_OF_YOUR_ESP

Switching in VERBOSE mode :

With PlatformIO + Vscode, you need to knoww the IP of your ESP. Then, update your upload process with the TCP protocal and the according IP.

Uploading :

I use MQTT explorer to debug my MQTT flows.

Some values :

You can update on-the-fly the Reading Timeout of UART messages. See :

• Serial.Timeout
• Serial.ReadBytes
• I use SoftwareSerial for manipulating Serial

Through MQTT, you can push a unsigned int16 in a RAW message - This is the timeout used by ReadBytes to fill the buffer. Standard is 1000msec - I use 50ms.

Once published, you will see in your remotedebug flow :

You can totally break the OTA process if you push a bad code or if you overcharge the loop process of the Arduino.

I've chosen to use MQTT for easy integration to Home Assistant. ESP Home didn't allow me to fully customize my exploration process so I didn't use it.

In your configuration.yml :

mqtt:
  
  sensor: 

    - name: "Pool water tempetature"
      state_topic: "poolheater/values/water_in_temp"
      force_update: true
      unit_of_measurement: "°C"

    - name: "Pool water OUT tempetature"
      state_topic: "poolheater/values/water_out_temp"
      force_update: true
      unit_of_measurement: "°C"

    - name: "Heat pump status"
      state_topic: "poolheater/values/active_status"
      force_update: true
      
    - name: "Heat pump ambient air temperature"
      state_topic: "poolheater/values/air_ambient_temp"
      force_update: true

    - name: "Heat pump gaz temperature"
      state_topic: "poolheater/values/gaz_temp"
      force_update: true

    - name: "Heat pump coil temperature"
      state_topic: "poolheater/values/coil_temp"
      force_update: true

Results :

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

MIT