Work with Pace BMS on RS-232 instead of RS-485

[tumbochka]

Hello.
Is it hard to make the ESPHome32 to work via Pace BMS RS-232 (with a different UART - I mean the code change)?

[syssi]

There is no code change required (if the RS232 port supports the same protocol: Modbus). Just attach a RS232 converter instead a RS485 one.

[tumbochka]

I connected an esp32 to RS232 and used your example yaml to check:
https://github.com/syssi/esphome-pace-bms/blob/main/tests/esp8266-rs232-test.yaml
Just changed esp8266 to esp32 and pins.
I saw the output:

[17:49:50][I][ota:113]: Boot seems successful, resetting boot loop counter.
[17:49:50][D][esp32.preferences:114]: Saving 1 preferences to flash...
[17:49:51][D][esp32.preferences:143]: Saving 1 preferences to flash: 0 cached, 1 written, 0 failed
[17:49:51][D][uart_debug:158]: >>> "~250146C20000FD99\r"
[17:49:51][D][uart_debug:158]: <<< "~250146C20000FD99\r"
[17:49:53][D][uart_debug:158]: >>> "~25014642E002FFFD05\r"
[17:49:53][D][uart_debug:158]: <<< "~25014642E002FFFD05\r"
[17:49:55][D][uart_debug:158]: >>> "~250146C10000FD9A\r"
[17:49:55][D][uart_debug:158]: <<< "~250146C10000FD9A\r"
[17:49:57][D][uart_debug:158]: >>> "~250146C20000FD99\r"
[17:49:57][D][uart_debug:158]: <<< "~250146C20000FD99\r"
[17:49:59][D][uart_debug:158]: >>> "~25014642E002FFFD05\r"
[17:49:59][D][uart_debug:158]: <<< "~25014642E002FFFD05\r"
[17:50:01][D][uart_debug:158]: >>> "~250146C10000FD9A\r"
[17:50:01][D][uart_debug:158]: <<< "~250146C10000FD9A\r"
[17:50:03][D][uart_debug:158]: >>> "~250146C20000FD99\r"
[17:50:03][D][uart_debug:158]: <<< "~250146C20000FD99\r"
[17:50:05][D][uart_debug:158]: >>> "~25014642E002FFFD05\r"
[17:50:05][D][uart_debug:158]: <<< "~25014642E002FFFD05\r"
[17:50:07][D][uart_debug:158]: >>> "~250146C10000FD9A\r"
[17:50:07][D][uart_debug:158]: <<< "~250146C10000FD9A\r"
[17:50:09][D][uart_debug:158]: >>> "~250146C20000FD99\r"
[17:50:09][D][uart_debug:158]: <<< "~250146C20000FD99\r"
[17:50:11][D][uart_debug:158]: >>> "~25014642E002FFFD05\r"
[17:50:11][D][uart_debug:158]: <<< "~25014642E002FFFD05\r"
[17:50:13][D][uart_debug:158]: >>> "~250146C10000FD9A\r"
[17:50:13][D][uart_debug:158]: <<< "~250146C10000FD9A\r"
[17:50:15][D][uart_debug:158]: >>> "~250146C20000FD99\r"
[17:50:15][D][uart_debug:158]: <<< "~250146C20000FD99\r"
[17:50:17][D][uart_debug:158]: >>> "~25014642E002FFFD05\r"
[17:50:17][D][uart_debug:158]: <<< "~25014642E002FFFD05\r"
[17:50:19][D][uart_debug:158]: >>> "~250146C10000FD9A\r"
[17:50:19][D][uart_debug:158]: <<< "~250146C10000FD9A\r"
[17:50:21][D][uart_debug:158]: >>> "~250146C20000FD99\r"
[17:50:21][D][uart_debug:158]: <<< "~250146C20000FD99\r"
[17:50:23][D][uart_debug:158]: >>> "~25014642E002FFFD05\r"
[17:50:23][D][uart_debug:158]: <<< "~25014642E002FFFD05\r"
[17:50:25][D][uart_debug:158]: >>> "~250146C10000FD9A\r"
[17:50:25][D][uart_debug:158]: <<< "~250146C10000FD9A\r"
[17:50:27][D][uart_debug:158]: >>> "~250146C20000FD99\r"

Then I tried to use this yaml: https://github.com/syssi/esphome-pace-bms/blob/main/esp32-example.yaml
And I see:

[18:12:29][C][mdns:112]: mDNS:
[18:12:29][C][mdns:113]:   Hostname: bms
[18:12:29][C][ota:093]: Over-The-Air Updates:
[18:12:29][C][ota:094]:   Address: bms.local:3232
[18:12:29][C][api:138]: API Server:
[18:12:29][C][api:139]:   Address: bms.local:6053
[18:12:29][C][api:143]:   Using noise encryption: NO
[18:12:32][D][uart_debug:114]: >>> 01:03:00:00:00:08:44:0C
[18:12:32][W][modbus:108]: Modbus CRC Check failed! F020!=00
[18:12:32][D][uart_debug:114]: <<< 01:03:00:00:00:08:44:0C
[18:12:32][D][uart_debug:114]: >>> 01:03:00:00:00:08:44:0C
[18:12:32][W][modbus:108]: Modbus CRC Check failed! F020!=00
[18:12:32][D][uart_debug:114]: <<< 01:03:00:00:00:08:44:0C
[18:12:32][D][uart_debug:114]: >>> 01:03:00:00:00:08:44:0C
[18:12:32][W][modbus:108]: Modbus CRC Check failed! F020!=00
[18:12:32][D][uart_debug:114]: <<< 01:03:00:00:00:08:44:0C
[18:12:32][D][uart_debug:114]: >>> 01:03:00:00:00:08:44:0C
[18:12:32][W][modbus:108]: Modbus CRC Check failed! F020!=00
[18:12:33][D][uart_debug:114]: <<< 01:03:00:00:00:08:44:0C
[18:12:33][D][uart_debug:114]: >>> 01:03:00:00:00:08:44:0C
[18:12:33][W][modbus:108]: Modbus CRC Check failed! F020!=00
[18:12:33][D][uart_debug:114]: <<< 01:03:00:00:00:08:44:0C
[18:12:33][D][modbus_controller:032]: Modbus command to device=1 register=0x00 countdown=0 no response received - removed from send queue
[18:12:33][D][uart_debug:114]: >>> 01:03:00:09:00:04:94:0B
[18:12:33][W][modbus:108]: Modbus CRC Check failed! F020!=09

Does it mean that modbus is not supported or am I doing anything wrong?