esphome-winix-c545

An ESPHome component for the Winix C545 air purifier.

Features

• Full local control of the air purifier via Home Assistant or MQTT.
• Physical device controls remain functional and changes are immediately reflected in the frontend.
• AQI, AQI indicator, filter age, filter lifetime and light intensity sensors.
• Switch to control Plasmawave.
• Auto and Sleep modes are implemented as fan presets.
• Piggybacks on the OEM protocol with minimal hardware modifications required.
  • The OEM app can (theoretically) remain functional.

Requirements

• ESP32
  • ESP8266 may work but lacks a free hardware UART.
  • A Raspberry Pi Pico W has also been used successfully.
• ESPHome 2023.10 or above
  • Older versions may function but have not been tested.
• A bi-directional logic level shifter.
  • Pictured here is the Adafruit TXB0104 Bi-Directional Level Shifter.
• Winix C545 Air Purifier
• Soldering iron, solder and some small wire.

Setup

In this setup a ESP32-PICO-KIT V4.1 was used due to its availability and small size.

Disassemble The Device

Disassemble the air purifier and remove the control board.

1. Remove the 5 screws around the filter compartment and release the plastic clips at the bottom of the device to remove the front panel.
2. Remove the 4 screws and plastic clips securing the control panel.
3. Disconnect the wire harness from the control board to free the control panel assembly.
4. Remove the 3 screws securing the control board.

Identify The Board

Identify the board and ensure it matches the information below.

Board revision

Winix Inc
C545 Display PBA
Rev 1.0

WiFi module

I&C Technology
WFM60-SFP201

If your board differs, STOP! It is very likely you will damage the board if you disregard this warning.

See the wiki for an alternate board design.

Wiring

Using the photos as reference, connect the marked points to the ESP32 pins.

NOTE: The host MCU uses 5 V logic so a level shifter is necessary to interface with the 3.3 V ESP32.

Board Point	ESP32 Pin	Notes
TX	IO26 (via level shifter)	WiFi UART Tx (WiFi->MCU)
RX	IO25 (via level shifter)	WiFi UART Rx (MCU->WiFi)
5V	EXT_5V (5V)	5 V Supply
GND	Ground	Ground
Q16	N/A	WiFi RESETn Tie to ground to disable OEM WiFi

UART & Power Points

RESETn Point

Final Assembly

Configure ESPHome Node

See this configuration snippet for a more complete example or use the minimal configuration below.

external_components:
  # Pull from Github
  - source: github://mill1000/esphome-winix-c545@main
    components: [winix_c545]

uart:
  - tx_pin: 26
    rx_pin: 25
    baud_rate: 115200

winix_c545:

fan:
  - platform: winix_c545
    name: Winix C545 Air Purifier

sensor:
  - platform: winix_c545
    filter_age:
      name: Filter Age
    filter_lifetime:
      name: Filter Lifetime
    aqi:
      name: AQI
    light:
      name: Light Intensity

text_sensor:
  - platform: winix_c545
    aqi_indicator:
      name: AQI Indicator

switch:
  - platform: winix_c545
    plasmawave:
      name: Plasmawave