CB3S Invalid Message Checksum, Initialization failed at init_state 1

[haideralipunjabi]

Hi

I have a Fan Controller based on CB3S / bk7231n chip. On every cold boot, there's a chance (~70%) that it won't initialise properly, and I can't figure out a fix.

Here are the logs

00:36:43 | [W] | [tuya:119] | Tuya Received invalid message checksum 71!=6A
-- | -- | -- | --
00:36:43 | [V] | [tuya:438] | Sending Tuya: CMD=0x01 VERSION=0 DATA=[] INIT_STATE=1
00:36:43 | [D] | [api:103] | Accepted 192.168.1.201
00:36:44 | [V] | [api.connection:1427] | Hello from client: 'Home Assistant 2025.7.2' \| 192.168.1.201 \| API Version 1.10
00:36:44 | [W] | [component:170] | Component api cleared Warning flag
00:36:44 | [W] | [component:237] | Component api took a long time for an operation (214 ms).
00:36:44 | [W] | [component:238] | Components should block for at most 30 ms.
00:36:44 | [V] | [tuya:438] | Sending Tuya: CMD=0x01 VERSION=0 DATA=[] INIT_STATE=1
00:36:44 | [D] | [api.connection:1446] | Home Assistant 2025.7.2 (192.168.1.201): Connected successfully
00:36:44 | [W] | [tuya:119] | Tuya Received invalid message checksum 00!=FF
00:36:44 | [E] | [tuya:464] | Initialization failed at init_state 1

Here is my config

esphome:
  name: bedroom-fan
  friendly_name: Bedroom Fan

ota:
  - platform: esphome
    password: <redacted>

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  manual_ip:
    static_ip: 192.168.1.105
    gateway: 192.168.1.1
    subnet: 255.255.255.0

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Bedroom-Fan Fallback Hotspot"
    password: "aoQ75pvuSSH4"

bk72xx:
  board: cb3s

logger:
  level: VERY_VERBOSE
  baud_rate: 0

web_server:

captive_portal:

mdns:

api:
  encryption:
    key:  <redacted>

text_sensor:
  - platform: libretiny
    version:
      name: LibreTiny Version

uart:
  rx_pin: RX1
  tx_pin: TX1
  baud_rate: 9600

tuya:
  # DPIDs processed from schema model: 000004351e

switch:
  - platform: tuya
    switch_datapoint: 1
    name: Switch
  - platform: tuya
    switch_datapoint: 14
    name: Child Lock

number:
  - platform: tuya
    number_datapoint: 3
    name: Fan Speed
    min_value: 1
    max_value: 5
    step: 1

I also tried with other versions of libretiny (1.8.0, 1.9.1) and also tried LT_SERIAL_BUFFER_SIZE: 512, but nothing resolved this.

[szupi-ipuzs]

This is more of esphome issue than libretiny and it's related to how they handle tuya messages.
I observed the same with some especially talkative tuyamcu devices, like eg. tuya air quality detector which sends a lot of data within seconds.
I was able to improve this behavior (but not fix completely) in my uyat external component. I do plan to also create a PR in esphome's original tuya component.