Issue integrating 100balance BMS with ESPHome via RS-485

ESPHome
22

sorry, i wrote 0x02 instead of 0x01

23 
[17:22:33][D][uart_debug:114]: >>> 81 03 00 30 00 01 9B C5
[17:22:33][W][modbus:144]: Got Modbus frame from unknown address 0x51! 
[17:22:33][D][uart_debug:114]: <<< 51 03 02 00 41 B8 78
[17:22:33][D][uart_debug:114]: >>> 81 03 00 30 00 01 9B C5
[17:22:33][W][modbus:144]: Got Modbus frame from unknown address 0x51! 
[17:22:33][D][uart_debug:114]: <<< 51 03 02 00 41 B8 78
[17:22:33][D][uart_debug:114]: >>> 81 03 00 30 00 01 9B C5
[17:22:33][W][modbus:144]: Got Modbus frame from unknown address 0x51!
24

And it doesn’t pass it to the sensor value, right?

1 Like
25

I had a quick look at modbus library and I think there is no way to get the data with it.
But you could get it from uart debug and output it in template sensor.

26

is there an example of how to do this?

27

I have never tried, but I’m positive that you can make it.
Read the documentation for debugging

and have a look at this thread:

28

the problem is that each time a different amount of data arrives

im1
im1896×962 27.3 KB

29

No idea what’s going on there. Some parameters incorrect I guess.

Modbus request is always 8 bytes and reply for single register is always 7 bytes.
So the logic would be: if byte 0 is 0x51, result is byte 4

30

this is uart log

uart:
  tx_pin: D6
  rx_pin: D7
  baud_rate: 9600
  debug:
    direction: BOTH
    dummy_receiver: true
#    after:
#      delimiter: "\Q\x03"
#      bytes: 127
    sequence:
      - lambda: |-
          UARTDebug::log_string(direction, bytes);
          UARTDebug::log_hex(direction, bytes, ':');
          ESP_LOGD("main", "Response data only had %d bytes!!", bytes.size() );

interval:
  - interval: 5sec
    then:
      - uart.write: [0x81, 0x03, 0x00, 0x00, 0x00, 0x7F, 0x1B, 0xEA]
31

I think you should have just one uart debug, try to remove the first line of your lambda.
Also, do you have automatic flow control on your rs485-converter ? Or DE RE pins?

32

The code above is the connection via uart.
To connect via rs485, other pins and an adapter are used

Deleting a row in a lambda does nothing
Data comes with different lengths :cry:

33

So even this was received without RS485 ?

34

it was received by rs485

35

I don’t follow you. Your BMS have options to communicate(modbus) through TTL or Rs485?

36

my BMS has both UART and RS485 connections

37

with identic protocol?

38

im2
im2682×961 24.8 KB

good news. I began to consistently receive 259 bytes per UART

the description of the protocols is identical

39

More importantly they begin with 51 !
Ok from there grab the byte 4 and you are good to go

Edit: response doesn’t look good even if it starts so…

40

You should go back to code where output is like this:

[17:22:33][D][uart_debug:114]: <<< 51 03 02 00 41 B8 78
[17:22:33][D][uart_debug:114]: >>> 81 03 00 30 00 01 9B C5

Requesting either with modbus component or just with uart without additional debug code.

When you have solid 7 bytes response, try with simple code


  baud_rate: 9600
  debug:
    direction: BOTH
    dummy_receiver: false
    after:
      delimiter: "\n"
   sequence:
      - lambda: |-
          UARTDebug::log_hex(direction, bytes, ':');
          ESP_LOGD("main", "Response data only had %d bytes!!", bytes.size() );
41

The problem is that on rs485 I get different response lengths. but through the UART connection I began to receive consistently the same length of response