Notes on Smartmi Evaporative Humidifier 2 (zhimi.humidifier.ca4) #26
Description
Pins:
Commands used to backup stock firmware:
python esptool.py -p /dev/ttyUSB0 read_flash 0x0 0x400000 original-firmware.bin
(windows version, only one that worked)
esptool.exe -p COM9 read_flash 0x0 0x400000 original-firmware.bin
Do not power up the board via serial adapter. Use standard power brick provided with humidifier.
Bridge gpio0 and gpio2, then connect gpio2 to ground (for example gnd for STM serial)
Mobo is sealed with some slimy substance to prevent corrosion due to the vapor, hence little bit more heat for soldering is useful. I didn't find any test point that is connected gpio2. There is tiny gpio0 TP on the other side of mobo but it's not a hole and it's pretty far from gnd, so it's easier to solder all at the same side of board.
Working (for me) esp config. Replace "xxx" with your keys or just use the variable from secret.yaml.
Water level readings are broken for me, but this is due to long dead (probably shorted) sensor above the power port. Typical failure of this model. Speaking from experience if you get values above 100% (or "unknown" state in HA) that either means your sensor is dead or it's gonna die soon.
Source is temporary because repo's version doesn't compile. It's taken from one of the comments.
# https://home.miot-spec.com/spec/zhimi.humidifier.ca4
external_components:
source: github://pchmura4/esphome-miot@main
esphome:
name: living_room_air_humidifier
friendly_name: Living Room Air Humidifier
comment: Smartmi Evaporative Humidifier 2 (zhimi.humidifier.ca4)
project:
name: "dhewg.esphome-miot"
version: "zhimi.humidifier.ca4"
esp32:
board: esp32doit-devkit-v1
framework:
type: esp-idf
sdkconfig_options:
CONFIG_FREERTOS_UNICORE: y
advanced:
ignore_efuse_mac_crc: true
logger:
level: INFO
api:
encryption:
key: "xxx"
reboot_timeout: 0s
services:
- service: mcu_command
variables:
command: string
then:
- lambda: 'id(miot_main).queue_command(command);'
ota:
- platform: esphome
password: "xxx"
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
ap:
ssid: "Mihumidifier Fallback"
password: "xxx"
uart:
tx_pin: GPIO17
rx_pin: GPIO16
baud_rate: 115200
miot:
id: miot_main
switch:
- platform: "miot"
miot_siid: 2
miot_piid: 1
name: "Power"
icon: mdi:power
- platform: "miot"
miot_siid: 2
miot_piid: 8
name: "Dry"
icon: mdi:water-minus
- platform: "miot"
miot_siid: 4
miot_piid: 1
name: "Notification Sounds"
icon: mdi:volume-high
entity_category: config
- platform: "miot"
miot_siid: 6
miot_piid: 1
name: "Child Lock"
icon: mdi:lock
entity_category: config
- platform: "miot"
miot_siid: 7
miot_piid: 5
name: "Clean Mode"
icon: mdi:water-minus
entity_category: config
select:
- platform: "miot"
miot_siid: 2
miot_piid: 5
name: "Fan level"
icon: mdi:fan
options:
0: "Auto"
1: "Low"
2: "Medium"
3: "High"
- platform: "miot"
miot_siid: 5
miot_piid: 2
name: "Display brightness"
icon: mdi:brightness-6
entity_category: config
options:
0: "Dark"
1: "Glimmer"
2: "Brightest"
sensor:
- platform: "miot"
miot_siid: 2
miot_piid: 2
name: "Device Fault Code"
icon: mdi:fan-alert
entity_category: diagnostic
- platform: "miot"
miot_siid: 3
miot_piid: 7
name: "Temperature"
unit_of_measurement: "°C"
device_class: temperature
state_class: "measurement"
icon: mdi:thermometer
- platform: "miot"
miot_siid: 3
miot_piid: 9
name: "Relative Humidity"
unit_of_measurement: "%"
device_class: humidity
state_class: "measurement"
icon: mdi:water-percent
- platform: "miot"
miot_siid: 2
miot_piid: 7
name: "Water Level"
unit_of_measurement: "%"
state_class: "measurement"
icon: mdi:water-percent
filters:
- clamp:
min_value: 0
max_value: 100
ignore_out_of_range: true
- platform: "miot"
miot_siid: 2
miot_piid: 11
name: "Motor Speed"
unit_of_measurement: "rpm"
icon: mdi:fan
- platform: "miot"
miot_siid: 7
miot_piid: 1
name: "Actual Speed"
unit_of_measurement: "rpm"
icon: mdi:fan
- platform: internal_temperature
name: "MCU Temperature"