Talk to a Jiabaida Battery Management System over RS485. Tested with an ESP32 and a JBD-SP04S010A. Might also work with UART.

• See more on JBD commands and wiring in include/jbdbms.h
• See usage in examples/ directory
  • Hello: print battery voltage to demonstrate JbdBms usage
  • Test: uses all functions and prints results to check functionality
  • Monitor: regularly check values of the device and report changes (on serial, syslog and influx db). Also provide values as json and allow toggling mosfet status for charging and discharging on a simple web interface.

    > influx -precision rfc3339 --database JbdBms --execute "select * from Status where time > '2022-10-24T07:32:26Z' and time < '2022-10-24T07:33:55Z' order by time"
    name: Status
    TODO provide real example...
    

• Init the serial port with 9600 baud (TODO check 8N1) before calling JbdBms class methods.
  • ESP32 HardwareSerial, default pins

    Serial2.begin(9600, SERIAL_8N1);

  • ESP8266 SoftwareSerial

    SoftwareSerial port;
    ... 
    port.begin(9600, SWSERIAL_8N1, rx_pin, tx_pin);

  • ESP8266 hardware serial with alternate rx/tx pins 13/15 (not tested)

    Serial.begin(9600); Serial.swap();

• Complete example
  • Get Status

  #include <Arduino.h>
  #include <jbdbms.h>
  
  #define RS485_DIR_PIN 22             // Explicit DE/!RE pin, -1 if board does automatic direction
  
  JbdBms jbdbms(Serial2);              // Uses ESP32 2nd serial port to communicate with RS485 (or UART?) adapter
  
  void setup() {
     Serial.begin(115200);
     Serial2.begin(9600, SERIAL_8N1);  // Init serial port with default pins 16 and 17 for RX and TX
     jbdbms.begin(RS485_DIR_PIN);      // Init RS485 communication
  }
  
  void loop() {
     JbdBms::Status_t status;
     
     if (jbdbms.getStatus(status)) {   // Get current global status
        Serial.printf("Voltage: %u\n", status.voltage);
     }
  
     delay(10000);
  }

Thank you Jaibaida for providing the relevant protocol information!

Comments welcome, Joachim Banzhaf