Reading RS232 data from weighing Scale using ESPHOME

ESPHome
1

Hi, I used custom components to read rs232 data from a weighing scale through esp8266 using max232 mini board. By esphome logs I can see the correct continuous serial data, but I cannot display the values as a sensor in homeassistant. my need is to continuously update the homeassistant sensor using the text sensor serial data. Any help is highly appreciated.

esphome:
  name: a12e
  platform: ESP8266  # Use ESP32 if applicable
  board: nodemcuv2    # Adjust this according to your ESP module
  includes:
    - uart_read_line_sensor.h

wifi:
  ssid: 
  password: 

logger:

api:
  encryption:
    key: 

ota:
  password: 

uart:
  id: uart_bus
  tx_pin: GPIO15
  rx_pin: GPIO13
  baud_rate: 9600

text_sensor:
- platform: custom
  lambda: |-
    auto my_custom_sensor = new UartReadLineSensor(id(uart_bus));
    App.register_component(my_custom_sensor);
    return {my_custom_sensor};
  text_sensors:
    id: "uart_readline"
1 Like
2

HI and welcome to HA. Can you please post your logs as well?

3

Thanks, yeah sure.

4

Hi Daryl, This is the ESPHome Log I’m getting

[23:28:33][C][uart.arduino_esp8266:102]: UART Bus:
[23:28:33][C][uart.arduino_esp8266:103]:   TX Pin: GPIO15
[23:28:33][C][uart.arduino_esp8266:104]:   RX Pin: GPIO13
[23:28:33][C][uart.arduino_esp8266:106]:   RX Buffer Size: 256
[23:28:33][C][uart.arduino_esp8266:108]:   Baud Rate: 9600 baud
[23:28:33][C][uart.arduino_esp8266:109]:   Data Bits: 8
[23:28:33][C][uart.arduino_esp8266:110]:   Parity: NONE
[23:28:33][C][uart.arduino_esp8266:111]:   Stop bits: 1
[23:28:33][C][uart.arduino_esp8266:115]:   Using software serial
[23:28:33][C][mdns:108]: mDNS:
[23:28:33][C][mdns:109]:   Hostname: a12e
[23:28:33][C][ota:093]: Over-The-Air Updates:
[23:28:33][C][ota:094]:   Address: a12e.local:8266
[23:28:33][C][ota:097]:   Using Password.
[23:28:33][C][api:138]: API Server:
[23:28:33][C][api:139]:   Address: a12e.local:6053
[23:28:33][C][api:141]:   Using noise encryption: YES
[23:29:19][D][text_sensor:064]: 'uart_readline': Sending state '\xffww-135.60kg'
[23:29:19][D][text_sensor:064]: 'uart_readline': Sending state 'ww-135.60kg'
[23:29:19][D][text_sensor:064]: 'uart_readline': Sending state 'ww-135.60kg'
[23:29:19][D][text_sensor:064]: 'uart_readline': Sending state 'ww-135.60kg'
[23:29:19][D][text_sensor:064]: 'uart_readline': Sending state 'ww-135.60kg'
[23:29:19][D][text_sensor:064]: 'uart_readline': Sending state 'ww-135.60kg'
[23:29:19][D][text_sensor:064]: 'uart_readline': Sending state 'ww-135.60kg'
[23:29:20][D][text_sensor:064]: 'uart_readline': Sending state 'ww-135.60kg'

ESP Uart reads the same weight as displayed in the scale.

20231021_233249
20231021_2332491920×1440 187 KB

5

By figuring the below configuration the values got exposed in homeassistant.

  • internal (Optional, boolean): Mark this component as internal. Internal components will not be exposed to the frontend (like Home Assistant). Only specifying an id without a name will implicitly set this to true.

I added the name for the text sensor in the code.

text_sensor:
- platform: custom
  lambda: |-
    auto my_custom_sensor = new UartReadLineSensor(id(uart_bus));
    App.register_component(my_custom_sensor);
    return {my_custom_sensor};
  text_sensors:
    name: "Weight Machine"
    id: "uart_readline"

Now I’m trying to separate ‘ww’ text from the output.
image

6

Finally managed to remove the ‘ww’ preffix and converted the string to float, this is my final esphome code.

uart:
  id: uart_bus
  tx_pin: GPIO15
  rx_pin: GPIO13
  baud_rate: 9600

text_sensor:
- platform: custom
  lambda: |-
    auto my_custom_sensor = new UartReadLineSensor(id(uart_bus));
    App.register_component(my_custom_sensor);
    return {my_custom_sensor};
  text_sensors:
    filters: 
    - substitute:
      - "ww -> "
    id: "uart_readline"

sensor:
  - platform: template
    update_interval: 1s
    name: "Weight"
    id: weight_sensor
    unit_of_measurement: "Kg"
    lambda: |-
      std::string x = id(uart_readline).state;
      return atof(x.c_str());
1 Like