Suport for Smart Purifier 4 Compact (board AC-M18-SC)

[tujdfhxyvweyka5]

Hello,

I have a Air Purifier 4 Compact (zhimi.airp.cpa4) with a ESP32-WROOM-32D that I successfully flashed using the toolchain. However, it doesn't seem to work as expected. At first, I noticed that the buttons didn't light and the initial beep would not be heard as with the stock firmware.

In the logs, I noticed that the firmware would constantly repeat over and over the same sequences:

[21:48:16][D][miot:139]: Queuing MCU command 'get_properties 2 1 2 2 2 4 3 4 4 1 4 3 4 4 6 1 8 1 9 1 9 11 13 2'
[21:48:39][D][miot:139]: Queuing MCU command 'set_properties 11 4 60'
[21:49:16][D][miot:139]: Queuing MCU command 'get_properties 2 1 2 2 2 4 3 4 4 1 4 3 4 4 6 1 8 1 9 1 9 11 13 2'
[21:49:39][D][miot:139]: Queuing MCU command 'set_properties 11 4 60'

It seems no action are being taken into account.

I was wondering if the communication with the MCU is operational. I noticed that if I invert the UART pins for MCU serial communication I obtain the same output.

For those who are interested, here's a picture of my board, with the mandatory flashing pins highlighted.

Not seen on the photo the board model: AC-M18-SC_B01

I also join with this issue the stock firmware logs and the complete ESPHome firmware logs:

logs_zhimi.airp.cpa4_run.log stock_firmware_ac-m18-sc.log

Also the MIOT specs:

https://home.miot-spec.com/spec/zhimi.airp.cpa4

Here's the config used for this project:

# https://home.miot-spec.com/spec/zhimi.airp.cpa4

external_components:
  source: github://dhewg/esphome-miot@main

esphome:
  name: purifier
  friendly_name: Air Purifier
  comment: Xiaomi Smart Air Purifier 4 Compact (zhimi.airp.cpa4)
  project:
    name: "dhewg.esphome-miot"
    version: "zhimi.airp.cpa4"

esp32:
  board: esp32dev
  framework:
    type: esp-idf
    sdkconfig_options:
      CONFIG_FREERTOS_UNICORE: y
    advanced:
      ignore_efuse_mac_crc: true

logger:
  level: DEBUG

api:
  encryption:
    key: !secret api_encryption_key
  reboot_timeout: 0s
  services:
    - service: mcu_command
      variables:
        command: string
      then:
        - lambda: 'id(miot_main).queue_command(command);'

ota:
  password: !secret ota_password

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

captive_portal:

uart:
  tx_pin: GPIO17
  rx_pin: GPIO16
  baud_rate: 115200

miot:
  id: miot_main
  miot_heartbeat_siid: 11
  miot_heartbeat_piid: 4

switch:
  - platform: "miot"
    miot_siid: 2
    miot_piid: 1
    name: "Power"
    icon: mdi:power
  - platform: "miot"
    miot_siid: 6
    miot_piid: 1
    name: "Notification Sounds"
    icon: mdi:volume-high
    entity_category: config
  - platform: "miot"
    miot_siid: 8
    miot_piid: 1
    name: "Child Lock"
    icon: mdi:lock
    entity_category: config

select:
  - platform: "miot"
    miot_siid: 2
    miot_piid: 4
    name: "Mode"
    options:
      0: "Auto"
      1: "Sleep"
      2: "Favorite"
  - platform: "miot"
    miot_siid: 13
    miot_piid: 2
    name: "Display Brightness"
    icon: mdi:brightness-6
    entity_category: config
    options:
      0: "Off"
      1: "Low"
      2: "High"

text_sensor:
  - platform: "miot"
    miot_siid: 1
    miot_piid: 5
    miot_poll: false
    name: "Serial Number"
    icon: mdi:numeric
    entity_category: diagnostic
  - platform: "miot"
    miot_siid: 2
    miot_piid: 2
    name: "Device Fault"
    icon: mdi:fan-alert
    entity_category: diagnostic
    filters:
      - map:
        - "0 -> No Faults"
        - "2 -> Motor Stop"
        - "3 -> Sensor Lost"


number:
  - platform: "miot"
    miot_siid: 9
    miot_piid: 11
    name: "Favorite Level"
    icon: mdi:speedometer
    min_value: 0
    max_value: 14
    step: 1
  - platform: "miot"
    miot_siid: 9
    miot_piid: 9
    name: "Manual Level"
    icon: mdi:speedometer
    min_value: 1
    max_value: 11
    step: 1

sensor:
  - platform: "miot"
    miot_siid: 3
    miot_piid: 4
    name: "PM2.5 Density"
    unit_of_measurement: "µg/m³"
    device_class: pm25
    state_class: "measurement"
  - platform: "miot"
    miot_siid: 4
    miot_piid: 1
    name: "Filter Life Level"
    unit_of_measurement: "%"
    icon: mdi:air-filter
  - platform: "miot"
    miot_siid: 4
    miot_piid: 3
    name: "Filter Used Time"
    entity_category: diagnostic
    unit_of_measurement: "h"
    icon: mdi:air-filter
  - platform: "miot"
    miot_siid: 4
    miot_piid: 4
    name: "Filter Lifetime Remaining"
    entity_category: diagnostic
    unit_of_measurement: "d"
    icon: mdi:air-filter
  - platform: "miot"
    miot_siid: 9
    miot_piid: 1
    name: "Motor Speed"
    unit_of_measurement: "rpm"
    icon: mdi:fan

button:
  - platform: "miot"
    miot_siid: 2
    miot_aiid: 1
    name: "Toggle Power"
    icon: mdi:power
  - platform: "miot"
    miot_siid: 9
    miot_aiid: 1
    name: "Toggle Mode"
    icon: mdi:cached