[Help needed] can't update binary sensor status

[piotr-placzek]

Hi, I'm trying to use esphome to communicate with an external device via uart for controlling and monitoring this device.
I started with simple binary sensor configuration (yaml bellow) and connecting uart gpio pins to pc using CP2102. I noticed that the esphome doesn't send any data to my external device (currently it's pc) for reading sensor status. Even if I write data to serial I don't notice sensor state change in home assistant. Also I see that tx indicator lights when I'm sending data, but rx don't just like esp doesn't send anything.

What am I doing wrong?

config:

esphome:
  name: dgus
  friendly_name: DGUS

esp8266:
  board: esp01_1m

# Enable logging
logger:
  baud_rate: 0

# Enable Home Assistant API
api:
  batch_delay: 0ms
  encryption:
    key: "********"

ota:
  - platform: esphome
    password: "************"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  use_address: 192.168.1.6

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Dgus Fallback Hotspot"
    password: "********"

uart:
  baud_rate: 9600
  data_bits: 8
  parity: NONE
  stop_bits: 1
  rx_pin: GPIO3
  tx_pin: GPIO1

# https://community.home-assistant.io/t/easy-uart-parsing-esphome-component/843171
external_components:
  - source: github://eigger/espcomponents@latest
    components: [ uartex ]
    refresh: always

uartex:
  rx_timeout: 10ms
  tx_delay: 50ms
  tx_timeout: 500ms
  tx_retry_cnt: 3

  rx_header: [0x02, 0x01]
  tx_header: [0x02, 0x01]

  version:
    disabled: False
  error:
    disabled: False
  log:
    disabled: False

#packet on) 0x02 0x01 0x02 0x03 0x01
#   offset) head head 0    1    2
#packet off) 0x02 0x01 0x02 0x03 0x00

binary_sensor:
  - platform: uartex
    name: Binary_Sensor1
    state: [0x02, 0x03]
    state_on:
      offset: 2
      data: [0x01]
    state_off:
      offset: 2
      data: [0x00]

how I read data from serial at pc:
cat /dev/ttyUSB1

how I write data to serial at pc:
echo -e "\x02\x02\x02\x03\x01" > /dev/ttyUSB1

[eigger]

Try checking first whether the UART data is actually being received.

logger:
  level: DEBUG
uart:
  ...
  debug:

At the moment, the ESP device doesn’t have any code that sends data through UART. The HA status is sent via Wi-Fi.

Also, the parsing configuration for the data received from the PC is incorrect. You should set a footer or checksum.

If I try setting the header and footer manually, (0x0D, 0x0D)

echo -e "\x02\x02\x02\x03\x01\x0D\x0D" > /dev/ttyUSB1

uartex:
  ...
  rx_header: [0x02, 0x02]
  rx_footer: [0x0D, 0x0D]
  tx_header: [0x02, 0x02]
  tx_footer: [0x0D, 0x0D]

[piotr-placzek]

Sure. Communication between esp and ha is over wifi. I'm working with communication between esp end my device over uart.
I can not setup debugging because it's working on uart.
Why Should I use footer or checksum? Both params are otional, and communication protocol does not send it.

My code is copied directly from examples, btw...

Communication protocol:
header - 2 bytes
command - 1 byte
data length - 1 byte
data - 1 - 255 bytes

[eigger]

I thought you were sending the packets just for testing purposes.
The packet was provided just as a simple test example.
Please let me know if you have an actual protocol that you’re using.

Without a footer or checksum, the end of the data cannot be determined, which may cause a timeout.
If you increase the rx_timeout option sufficiently, you can parse the packets received during that period, but timeouts will keep occurring.
Fixed-size packets can be parsed by using the rx_length option, but variable-length packets without a footer or checksum are currently not supported.

[piotr-placzek]

Ok, I understand, propably I shoud be able to turn on CRC checksum.
frame syntax:
header: 2 bytes (0x5aa5)
length: 1 byte (including instruction, data and checksum)
instruction: 1 byte (x82 write or x83 read)
data: max 249 bytes
checksum: 2 bytes (CRC-16(x16*x15+x2+1))

it is described at page 2/41 of device manual (it's 4th page of pdf):
https://ecdn6.globalso.com/upload/p/1355/source/2024-11/DWIN-T5L-Smart-LCMs%E2%80%99-UART-C51-Program.pdf

Could you please provide me a solution for calculating that checksum in esp configuration file?

[eigger]

I think you can try it this way, but you’ll need to debug and test it.
If you encounter a checksum error, please send me a sample packet so I can review it again.

uartex:
  ...
  rx_header: [0x5A, 0xA5]
  tx_header: [0x5A, 0xA5]
  rx_checksum2: !lambda |-
      uint16_t crc = 0xFFFF;
      for (int i = 1; i < len; i++)
      {
          crc = crc16_reflected(crc, 0xA001, data[i]);
      }
      return { (uint8_t)(crc >> 8), (uint8_t)(crc) };
  tx_checksum2: !lambda |-
      uint16_t crc = 0xFFFF;
      for (int i = 1; i < len; i++)
      {
          crc = crc16_reflected(crc, 0xA001, data[i]);
      }
      return { (uint8_t)(crc >> 8), (uint8_t)(crc) };

[piotr-placzek]

we was talking long time ago, but i remember about it. i will return to this in few days fyi ;)

[piotr-placzek]

Well, it looks like working good. I don't understand how HA checks status. My device don't send any data if master not ask about it. Read command should be send, and status should be calculated basing on device's response. In my example I see only that only on/off commands are send 🤔

[eigger]

Did you simply press the switch ON button, or did the switch state change to ON at the moment the packet was received?
Based on the attached packet capture alone, I can’t find any packet that would cause the switch to turn ON.

[piotr-placzek]

I simple press switch visible in home assistant part of the screen above. I can not find any action like sending read command for getting status when I refresh ha page. Currently I have no access to physical device and I'm working on my workbench only. I'm confused will user see correct status directly after opening ha dashboard (state can be changed manually by pressing buttons on device control panel).