Seplos BMS 3.0 Help

[csw03]

Hello
i try different solution yaml file, different 485 boards but nothing can't comunicate with BMS

SEPLOS 3.0 Type C SPB05

BMS Seplos 3.0 im using ESP32 DEVKIT V2 from AZ Delivery
TX GPIO1
RX GPIO3

My conf YAML

substitutions:
  name: "seplos-bms-3"
  device_description: "Monitor and control a Seplos V3 BMS via RS485 (Modbus)"
  tx_pin: GPIO1
  rx_pin: GPIO3

esphome:
  name: ${name}
  comment: ${device_description}
  min_version: 2024.6.0
  project:
    name: "syssi.esphome-seplos-bms"
    version: 1.2.0
 
esp32:
  board: esp32dev
  framework:
    type: esp-idf

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  
  manual_ip:
    static_ip: 192.168.1.135
    gateway: 192.168.0.1
    subnet: 255.255.255.0




 
  ap:
    ssid: "Secondo-Esp Fallback Hotspot"
    password: "SpiXXXXXXXYQrQ"

captive_portal:

improv_serial:

web_server:
  port: 80  

   


ota:
  - platform: esphome
    password: "b785cXXXXXXXXXXXXXXXf6fc5de"



logger:
  level: DEBUG



api:
  encryption:
    key: "spQiuLNtXXXXXXXXXXXXXXXXXXXXXikwyA="



uart:
  - id: uart_0
    baud_rate: 19200
    tx_pin: ${tx_pin}
    rx_pin: ${rx_pin}
    debug:
      direction: BOTH
      dummy_receiver: false
    
    

modbus:
  - id: modbus0
    uart_id: uart_0
    send_wait_time: 200ms

modbus_controller:
  - id: bms0
    address: 0x00
    modbus_id: modbus0
    command_throttle: 200ms
    update_interval: 10s

sensor: /.............................................../

Communications Records 20241221_1305.txt

[syssi]

If you use GPIO1/GPIO3 you have to set the baud_rate of the logger component to 0. Could you provide a photo of your wiring?

[csw03]

i have correct yaml to baud_rate 0 of the logger, but nothing, here the rs485 module i using now

[syssi]

Your wiring isn't fine. Your RS485 requires flow control. It should look like this: https://github.com/syssi/esphome-solax-x1-mini?tab=readme-ov-file#rs485-ttl-module-with-flow-control-pin

The modbus section must be extended to control the flow:

modbus:
  - id: modbus0
    uart_id: uart_0
    send_wait_time: 200ms
    flow_control_pin: GPIO0

[csw03]

Finally all working good with GPIO0 flow control
Thank you so much for your help

[syssi]

Good job!

[csw03]

Maybe you know the address for can add the cell delta voltage ?
Thank you for your work

[syssi]

There is no dedicated register for the delta cell voltage but can calculate the delta using a template sensor by substract the min cell voltage from the max cell voltage:

https://github.com/syssi/esphome-seplos-bms/blob/main/docs/XZH%20BMS%20Modbus-RTU%20Protocol.pdf
https://github.com/syssi/esphome-seplos-bms/blob/main/esp8266-seplos-v3-example.yaml#L192-L218

[csw03]

Perfect, thank you