Actron Air ESPHome Integration for Home Assistant

An ESPHome external component for reading and decoding pulse trains from the Actron Air ESP32 keypad display, plus a Home Assistant integration with climate entity and custom Lovelace card.

Key Features

• Interrupt-driven reading: Accurate pulse train capture
• 40-bit decoding: Full status from keypad display
• Temperature display: 7-segment decoder for setpoint
• 18 binary sensors: Mode, fan, zones, timers
• Error tracking: Bit count for monitoring reliability
• Type-safe config: ESPHome validation for all settings
• Climate entity: Full HVAC control with zone presets
• Custom Lovelace card: Retro keypad-style control interface

Hardware Requirements

• ESP32 (ESP-IDF framework)
• GPIO pin for pulse train input
• Connection to air conditioner keypad display output
• MCP4725 or MCP4726 DAC (I2C) for keypad button emulation
• BC548 NPN transistor
• Resistors: 20kΩ, 4.7kΩ, 1.2kΩ (0.5W or higher)

See the forum thread for detailed build instructions and wiring diagrams.

Compatible Systems

This integration works with Actron Air ducted systems that use the older-style wall controllers with a 4-wire interface (SENS, KEY, COMM, POWER).

Wall Controllers

Controller	Status	Notes
LM24	Confirmed	Multi-zone controller
LM7 / LM7-2W / LM7-2G	Community reported	7-day programmable, up to 8 zones
LM7-D	Community reported	Ultima Zone Control Master
AM7	Community reported	Original older controller

Air Conditioner Systems

Compatible:

• SRA series (e.g., SRA22C, SRA25C) - older multi-zone ducted systems
• SRD series (e.g., SRD175C, SRD22C) - older ducted systems
• ESP Plus, ESP Platinum, ESP Ultima with LM7/LM24 controllers
• Classic series (SRG models) with LM7/LM24 controllers

Not compatible:

• Systems with QUE controllers (different architecture)
• Systems with ActronConnect/ACM WiFi modules (post-2013)
• Serene Series with Easy Connect app

Installation

This project has two parts:

1. ESPHome component - Runs on your ESP32 to read the keypad and control the AC
2. Home Assistant integration - Provides climate entity and Lovelace card

Set up the ESPHome device first, then install the Home Assistant integration.

Step 1: ESPHome Device Setup

See ESPHome Configuration below for detailed setup instructions. The quickest way is to use the ESPHome package - just copy example_actron_air_keypad.yaml and customise for your setup.

Step 2: Home Assistant Integration

Once your ESPHome device is running, install the integration:

HACS (Recommended)

Or manually:

1. Open HACS in Home Assistant
2. Go to "Integrations" section
3. Click the three dots menu and select "Custom repositories"
4. Add https://github.com/johnf/actron-air-esphome with category "Integration"
5. Install "Actron Air ESPHome"
6. Restart Home Assistant
7. Go to Settings > Devices & Services > Add Integration
8. Search for "Actron Air ESPHome" and configure

The integration will automatically register the Lovelace card.

Manual Installation

1. Copy the custom_components/actron_air_esphome folder to your Home Assistant config/custom_components/ directory
2. Restart Home Assistant
3. Go to Settings > Devices & Services > Add Integration
4. Search for "Actron Air ESPHome" and configure

Lovelace Card Usage

Add the card to your dashboard:

type: custom:actron-air-esphome-card
entity_prefix: actron_air

Card Configuration Options

Option	Type	Default	Description
entity_prefix	string	required	Prefix for ESPHome entities (e.g., actron_air)
name	string	-	Card title (optional)
show_timer	boolean	true	Show timer controls
show_zones	boolean	true	Show zone buttons
zone_count	number	4	Number of zones to display (1-7)
zones	array	-	Custom zone names

Full Configuration Example

type: custom:actron-air-esphome-card
entity_prefix: actron_air
name: Air Conditioning
show_timer: true
show_zones: true
zone_count: 4
zones:
  - name: Bedrooms
  - name: Living Room
  - name: Kitchen
  - name: Office

Expected Entity Names

The card expects entities with the following naming pattern based on your entity_prefix:

Sensors:

• sensor.{prefix}_setpoint_temperature

Switches:

• switch.{prefix}_power
• switch.{prefix}_zone_1 through switch.{prefix}_zone_8

Binary Sensors:

• binary_sensor.{prefix}_cool
• binary_sensor.{prefix}_heat
• binary_sensor.{prefix}_auto
• binary_sensor.{prefix}_run
• binary_sensor.{prefix}_fan_low
• binary_sensor.{prefix}_fan_mid
• binary_sensor.{prefix}_fan_high
• binary_sensor.{prefix}_fan_continuous
• binary_sensor.{prefix}_inside
• binary_sensor.{prefix}_timer
• binary_sensor.{prefix}_zone_1 through binary_sensor.{prefix}_zone_8

Buttons:

• button.{prefix}_mode
• button.{prefix}_fan
• button.{prefix}_temp_up
• button.{prefix}_temp_down
• button.{prefix}_timer
• button.{prefix}_timer_up
• button.{prefix}_timer_down

ESPHome Configuration

The easiest way to get started is to use the ESPHome package, which includes all sensors, DAC controls, and button definitions. See example_actron_air_keypad.yaml for a complete example.

Quick Start (Using Package)

packages:
  actron_air: github://johnf/actron-air-esphome/actron_air_keypad.yaml@main

esphome:
  name: "my-aircon"
  friendly_name: My Air Conditioner

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

# Enable auto-discovery in Home Assistant
mdns:
  services:
    - service: "_actron_air"
      protocol: "_tcp"
      port: 6053
      txt:
        version: "1.0.0"
        name: "my-aircon"

That's it! The package includes everything you need:

• All 7 zones (remove unused ones with !remove if desired)
• DAC output for button emulation
• All binary sensors, switches, and buttons
• Configurable GPIO pins and voltage calibration via substitutions

Customising the Package

Override any defaults by adding a substitutions section before the package:

substitutions:
  gpio_keypad_pin: "GPIO32"    # Pin for keypad signal
  gpio_i2c_sda: "GPIO21"       # I2C SDA pin
  gpio_i2c_scl: "GPIO22"       # I2C SCL pin
  dac_output_address: "0x60"   # MCP4725 DAC I2C address
  # Voltage calibration (millivolts)
  voltage_zone_1: "725.0"
  voltage_zone_2: "663.0"
  # ... see actron_air_keypad.yaml for all options

packages:
  actron_air: github://johnf/actron-air-esphome/actron_air_keypad.yaml@main

Removing Unused Zones

If you have fewer than 7 zones, you can remove the unused ones:

packages:
  actron_air: github://johnf/actron-air-esphome/actron_air_keypad.yaml@main

# Remove zones 5-8 for a 4-zone system
switch:
  - id: !remove zone_5_switch
  - id: !remove zone_6_switch
  - id: !remove zone_7_switch
  - id: !remove zone_8_switch

  - id: !remove zone_5
  - id: !remove zone_6
  - id: !remove zone_7
  - id: !remove zone_8

Manual Configuration (Without Package)

If you prefer more control, you can use the external component directly:

external_components:
  - source:
      type: git
      url: https://github.com/johnf/actron-air-esphome
      ref: main
    components: [actron_air_esphome]

actron_air_esphome:
  pin: GPIO32

sensor:
  - platform: actron_air_esphome
    setpoint_temp:
      name: "Temperature"

binary_sensor:
  - platform: actron_air_esphome
    cool:
      name: "Cool Mode"
    heat:
      name: "Heat Mode"
    fan_high:
      name: "Fan High"
    zone_1:
      name: "Zone 1"
    zone_2:
      name: "Zone 2"

Climate Entity

The Home Assistant integration provides a climate entity with:

• HVAC Modes: Off, Cool, Heat, Auto, Fan Only
• Fan Modes: High, Medium, Low, High Cont, Medium Cont, Low Cont, Off
• Zone Presets: Individual zones and "All Zones"
• Optional: Current temperature and humidity from external sensors

Configure via Settings > Devices & Services after installing the integration.

Available ESPHome Sensors

Numeric Sensors (sensor platform)

• setpoint_temp - Temperature from 7-segment display (C)
• error_count - Error counter for monitoring

Status Sensors (binary_sensor platform)

• Mode: cool, heat, auto_mode, run
• Fan: fan_high, fan_mid, fan_low, fan_cont
• Zones: zone_1 through zone_8
• Other: inside, timer

Debug Sensors (text_sensor platform)

• bit_string - Raw 40-bit pulse train (internal use)

How It Works

Wires

There are 4 wires inside the wall unit that connect to the main supply:

• SENS - sensor line is directly connected to a thermistor
• KEY - connected to the keypad, it changes resistance to a different value when keys are pressed. This drops the voltage from 5V to different levels
• COMM - ground
• POWER - 19V and also data line that gets shifted into the LED. The protocol in this wire is quite simple: Data is transmitted every 200ms or so. It starts with a 16V->0V transition, followed by 41 other pulses, a zero or a one is determined by the time between the pulses. Each value is then shifted through the leds in the board.

Pulse Train Decoding

1. An interrupt handler captures falling edges on the ADC pin
2. Timing between edges determines if the pulse represents a '0' or '1'
3. 40 bits are collected to form a complete frame
4. The frame is decoded to extract display and LED status
5. Changes are published to Home Assistant sensors

Circuit Diagrams

The circuit connects the ESP32 to the Actron Air keypad interface. Fritzing source files are available in the fritzing/ directory.

Schematic

Veroboard Layout

Troubleshooting

No data received

• Check ADC pin connection
• Verify pulse train voltage levels
• Monitor error_count sensor for errors

Incorrect temperature readings

• Check 7-segment wiring/decoding
• Look at bit_string for raw data
• Verify display is showing temperature

Compile errors

• Ensure ESP-IDF framework is selected
• Check all Python files are present
• Validate YAML indentation

Card not showing

• Clear browser cache
• Check browser console for errors
• Verify the resource is loaded in Settings > Dashboards > Resources

---

Need Help?

• Check ESPHome logs: esphome logs your-device.yaml
• Validate config: esphome config your-device.yaml
• Review example_actron_air_keypad.yaml for complete setup

License

MIT License - Feel free to use and modify

Thanks

This builds on the work of many others:

• https://community.home-assistant.io/t/actron-aircon-esp32-controller-help/609062
• https://github.com/kursancew/actron-air-wifi
• https://github.com/brentk7/Actron-Keypad
• https://github.com/cjd/Actron-Keypad
• https://github.com/LaughingLogic/Actron-Keypad