MSP-AP71 no connection

[schumch]

Hi guys,
thanks for that great work! i have a problem. the connection doen't work. I get all the time "We think Heatpump is not connected anymore".

My setup:
Atom-Lite
MSZ-AP71 (inside wall unit)
There was a mel cloud gateway connectet by factory (not on cn105) I disconnected it.

My wiring:
CN105 ----- ATOM
1#YE - G26 - TX
2#WH - G32 - RX
3#RD - +5V
4#BL - GND

My yaml file:

substitutions:
  name: heatpump-1
  friendly_name: My Heatpump 1
  remote_temp_sensor: sensor.my_room_temperature # Homeassistant sensor providing remote temperature

esphome:
  name: ${name}
  friendly_name: ${friendly_name}

# For ESP8266 Devices
#esp8266:
#  board: d1_mini
#
#uart:
#  id: HP_UART
#  baud_rate: 2400
#  tx_pin: 1
#  rx_pin: 3

# For ESP32 Devices
esp32:
    board: m5stack-atom
    framework: 
        type: arduino

uart:
  id: HP_UART
  baud_rate: 2400
  tx_pin: GPIO26
  rx_pin: GPIO32

external_components:
  - source: github://echavet/MitsubishiCN105ESPHome
#    refresh: 0s

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "${friendly_name} ESP"
    password: !secret wifi_password

captive_portal:

# Enable logging
logger:
#  hardware_uart: UART1 # Uncomment on ESP8266 devices
  level: INFO
  logs:
    EVT_SETS : INFO
    WIFI : INFO
    MQTT : INFO
    WRITE_SETTINGS : INFO
    SETTINGS : INFO
    STATUS : INFO
    CN105Climate: WARN
    CN105: INFO
    climate: WARN
    sensor: WARN
    chkSum : INFO
    WRITE : WARN
    READ : WARN
    Header: INFO
    Decoder : INFO
    CONTROL_WANTED_SETTINGS: INFO
#  level: DEBUG
#  logs:
#    EVT_SETS : DEBUG
#    WIFI : INFO
#    MQTT : INFO
#    WRITE_SETTINGS : DEBUG
#    SETTINGS : DEBUG
#    STATUS : INFO
#    CN105Climate: WARN
#    CN105: DEBUG
#    climate: WARN
#    sensor: WARN
#    chkSum : INFO
#    WRITE : WARN
#    READ : WARN
#    Header: INFO
#    Decoder : DEBUG
#    CONTROL_WANTED_SETTINGS: DEBUG

# Enable Home Assistant API
api:
  #encryption:
   # key: !secret api_key


ota:
  platform: esphome # Required for ESPhome 2024.6.0 and greater

# Enable Web server.
web_server:
  port: 80

# Sync time with Home Assistant.
time:
  - platform: homeassistant
    id: homeassistant_time

# Text sensors with general information.
text_sensor:
  # Expose ESPHome version as sensor.
  - platform: version
    name: ESPHome Version
  # Expose WiFi information as sensors.
  - platform: wifi_info
    ip_address:
      name: IP
    ssid:
      name: SSID
    bssid:
      name: BSSID

# Sensors with general information.
sensor:
  - platform: homeassistant
    name: "Remote Temperature Sensor"
    entity_id: ${remote_temp_sensor} # Replace with your HomeAssistant remote sensor entity id, or include in substitutions
    internal: false
    disabled_by_default: true
    device_class: temperature
    state_class: measurement
    unit_of_measurement: "°C"
    filters:
    # Uncomment the lambda line to convert F to C on incoming temperature
    #  - lambda: return (x - 32) * (5.0/9.0);
      - clamp: # Limits values to range accepted by Mitsubishi units
          min_value: 1
          max_value: 40
          ignore_out_of_range: true
      - throttle: 30s
    on_value:
      then:
        - logger.log:
            level: INFO
            format: "Remote temperature received from HA: %.1f C"
            args: [ 'x' ]
        - lambda: 'id(hp).set_remote_temperature(x);'
        
  # Uptime sensor.
  - platform: uptime
    name: Uptime

  # WiFi Signal sensor.
  - platform: wifi_signal
    name: WiFi Signal
    update_interval: 120s

# Create a button to restart the unit from HomeAssistant. Rarely needed, but can be handy.
button:
  - platform: restart
    name: "Restart ${friendly_name}"

# Creates the sensor used to receive the remote temperature from Home Assistant
# Uses sensor selected in substitutions area at top of config
# Customize the filters to your application:
#   Uncomment the first line to convert F to C when remote temps are sent
#   If you have a fast or noisy sensor, consider some of the other filter
#   options such as throttle_average.
climate:
  - platform: cn105
    id: hp
    name: "${friendly_name}"
    icon: mdi:heat-pump
    visual:
      min_temperature: 10 # Adjust to your unit's min temp. SmartSet units can go to 10C for heating
      max_temperature: 31
      temperature_step:
        target_temperature: 1
        current_temperature: 0.5
    # Fahrenheit compatibility mode - uses Mitsubishi's "custom" unit conversions, set to
    # "true" for better support of Fahrenheit units in HomeAssistant
    fahrenheit_compatibility: false
    # Timeout and communication settings
    remote_temperature_timeout: 30min
    update_interval: 2s
    debounce_delay : 100ms
    # Various optional sensors, not all sensors are supported by all heatpumps
    compressor_frequency_sensor:
      name: Compressor Frequency
      entity_category: diagnostic
      disabled_by_default: true
    outside_air_temperature_sensor:
      name: Outside Air Temp
      disabled_by_default: true
    vertical_vane_select:
      name: Vertical Vane
      disabled_by_default: false
    horizontal_vane_select:
      name: Horizontal Vane
      disabled_by_default: true
    isee_sensor:
      name: ISEE Sensor
      disabled_by_default: true
    stage_sensor:
      name: Stage
      entity_category: diagnostic
      disabled_by_default: true
    sub_mode_sensor:
      name: Sub Mode
      entity_category: diagnostic
      disabled_by_default: true
    auto_sub_mode_sensor:
      name: Auto Sub Mode
      entity_category: diagnostic
      disabled_by_default: true
    input_power_sensor:
      name: Input Power
      disabled_by_default: true
    kwh_sensor:
      name: Energy Usage
      disabled_by_default: true
    runtime_hours_sensor:
      name: Runtime Hours
      entity_category: diagnostic
      disabled_by_default: true

i try different things:
-swap rx and tx
-use board: esp32doit-devkit-v1
framework: esp-idf
-made a downgrade to esphome 2025.7.5. because of a issue in 8.5.

thanks in advance for your ideas.

edit: i can control the unit! but don't get data

[Numbski]

Can control unit but don't get data.

Without doing any other troubleshooting, make absolute certain you have conductivity from the tx pin on cn105 and the rx pin on your esp. If you don't have that conductivity, you can't read anything from the heat pump. Tony Shadwick

[schumch]

Thanks. I will check if there is a electrical connection.

[SonarClouds]

I just solved my problem with the MSZ-RZ35VU by switching from an lolin d1 mini to az delivery d1 mini. I noticed the missing resistors on tx and rx on the lolin ^-^;

[schumch]

How can i check if there is a resitor? But i think this could not the problem. Be cause some other users already have good results with Atoma Lite.

[SonarClouds]

You are most likely right, but it could be an edge-case as well. I'm no expert but you could try adding a 470 ohm resistor in series to the RX line, like the AZ D1 mini have. In my case I can at least verify, that all my clones without the resistors did not work with my unit! Even the ESP32s did not work.

[schumch]

I've checked the connection and made also new cable. Still possible to send commands. But I don't get data from the unit. :(
Any ideas?

[schumch]

Still doesn't work.

I have soldered 480ohm resistors in rx and tx line.

I try to swap rx and tx.
I try several boards in the yaml-file (m5-stack-atom/framework: type: arduino and esp32-dev/framework: type:arduino) still not possible to read data. I can turn on the AC; but not possible to turn off :)

anybody an idea?

The original wifi adapter from mitsubishi is disconnected and was connected to CN110. The esp is connected to CN105.
The original melcloud is horrible.

Thanks in advance.