ESP32 based MQTT gateway for the CN105 protocol based Mitsubishi Heat Pumps (FTC5)

• General

  • Pull all known information for the HP (Heat Pump) in a loop (about one's a minute)
  • Publish all know information using MQTT. Topic: cn105gw/tele
  • The information is JSON encoded payload: {"Zone 1 Flow Temp Setpoint":"32"})
  • Provide a logging output by telnet

• Provide a webinterface for status of the gateway

  • You can set OTA enable/disble
  • Reboot the gateway
  • See the RSSI of the Wifi connection

I use a Lolin32 development board, but any ESP32 development board should work. Besides the Lolin32 I use a level shifting board (5v from HP to 3.3V Lolin32) and a DC-DC convertor. The DC-DC converter is use to power the Lolon32 board from the 12V provided by the CN105 interface. I power the Lolin32 with 5V.

The gateway will send MQTT data in the following format:

• Topic: cn105gw/tele/0x09 (0x09 indicates the command entry received from the Heat Pump)
• Payload: {"Zone1_Room_Temp_Setpoint":"21.0","Zone2_Room_Temp_Setpoint":"23.0","Zone1_Flow_Temp_Setpoint":"32.0","Zone2_Flow_Temp_Setpoint":"31.0","Legionalla_Temp_Setpoint":"65.0","Flow_Temp_Range_Max":"35.0","Flow_Temp_Range_Min":"25.0"}

Last will and testament is implemented:

• Topic: cn105gw/status
• If online: Payload = "Online" else Payload = "Offline"

Setting parameters is done in this format:

• Topic: cn105gw/cmnd
• Payload (json encoded as strings): {"SetFlowTemperature":"33"}

All settings are done in Topic: cn105gw/cmnd

• {"SetSystemModeOnOff":"1"}
  • 0=Standy
  • 1=On
• {"SetHotWaterMode":"1"}
  • 0=Normal
  • 1=Eco
• {"SetACMode":"1"}
  • 0=heating room mode
  • 1=heating flow temp
  • 2=heating heat curve
  • 3=cooling room tempmode
  • 4=cooling flow temp
  • 5=floor dryup
• {"SetFlowTemperature":"XX"}
  • XX=Temperature (whole decimal)
• {"SetBoilerTemperature":"XX"}
  • XX=Temperature (whole decimal)
• {"SetRoomTemperature":"XX"}
  • XX=Temperature (whole decimal)
• {"ForceDHW":"1"}
  • 1=ForceDHW
  • 0= Cancel/back Normal

With help of many on the internet.

Part of code from: https://github.com/SwiCago/HeatPump

Code/decode info: https://github.com/m000c400/Mitsubishi-CN105-Protocol-Decode

Unfortunatelly I am not a professional programmer so my code is hard to follow, not logical and will have many bugs