A library to communicate with an eSmart3 MPPT solar charge controller or similar device via RS485.

• See more on eSmart3 commands and wiring in include/esmart3.h
• See usage in examples/ directory
  • Test: uses most functions and prints results to check functionality
  • LiFePO: set parameters for charging LiFePO batteries. WARNING: I am no expert for LiFePO charging, better check before use :)
  • Monitor: regularly check most values of the device and report changes (on serial, syslog and influx db). Also provide values as json and allow toggling load output on a simple web interface.

    > influx -precision rfc3339 --database eSmart3 --execute "select * from ChgSts where time > '2022-10-24T07:32:26Z' and time < '2022-10-24T07:33:55Z' order by time"
    name: ChgSts
    time                 BatCap BatTemp BatVolt CO2     ChgCurr ChgMode ChgPower Fault      Host      InnerTemp LoadCurr LoadPower LoadVolt OutVolt PvVolt Serial   SystemReminder Version
    ----                 ------ ------- ------- ---     ------- ------- -------- -----      ----      --------- -------- --------- -------- ------- ------ ------   -------------- -------
    2022-10-24T07:32:27Z 96     22      132     1900544 0       0       0        0000001000 esmart3-1 23        0        0         0        0       1      34000083 0              1.0
    2022-10-24T07:33:41Z 96     22      132     1900544 0       0       0        0000001000 esmart3-1 23        0        0         132      0       1      34000083 0              1.0
    2022-10-24T07:33:42Z 96     22      130     1900544 0       0       0        0000001000 esmart3-1 23        157      202       129      0       1      34000083 0              1.0
    2022-10-24T07:33:43Z 95     22      132     1900544 0       0       0        0000001000 esmart3-1 23        0        0         0        0       1      34000083 0              1.0
    2022-10-24T07:33:44Z 96     22      132     1900544 0       0       0        0000001000 esmart3-1 23        0        0         0        0       1      34000083 0              1.0
    2022-10-24T07:33:48Z 96     22      132     1900544 0       0       0        0000001000 esmart3-1 23        0        0         132      0       1      34000083 0              1.0
    2022-10-24T07:33:50Z 95     22      126     1900544 0       0       0        0000001000 esmart3-1 23        423      520       123      0       1      34000083 0              1.0
    2022-10-24T07:33:51Z 95     22      126     1900544 0       0       0        0000001000 esmart3-1 23        433      532       123      0       1      34000083 0              1.0
    2022-10-24T07:33:52Z 95     22      126     1900544 0       0       0        0001001000 esmart3-1 23        424      521       123      0       1      34000083 0              1.0
    2022-10-24T07:33:53Z 95     22      126     1900544 0       0       0        0001001000 esmart3-1 23        421      517       123      0       1      34000083 0              1.0
    2022-10-24T07:33:54Z 95     22      132     1900544 0       0       0        0000001000 esmart3-1 23        0        0         0        0       1      34000083 0              1.0
    

• Init the serial port with 9600 baud and 8N1 before calling ESmart3 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
  • Toggle load

  #include <Arduino.h>
  #include <esmart3.h>
  
  #define RS485_DIR_PIN 22              // Explicit DE/!RE pin, -1 if board does automatic direction
  
  ESmart3 esmart3(Serial2);             // Uses ESP32 2nd serial port to communicate with RS485 adapter
  
  void setup() {
     Serial2.begin(9600, SERIAL_8N1);  // Init serial port with default pins 16 and 17 for RX and TX
     esmart3.begin(RS485_DIR_PIN);     // Init RS485 communication
  }
  
  void loop() {
     bool on_off;
     
     if (esmart3.getLoad(on_off)) {    // Get current load output status
        esmart3.setLoad(!on_off);     // Toggle current load output
     }
  
     delay(10000);
  }

Thanks @altelch and @skagmo for helpful information.

Comments welcome, Joachim Banzhaf