reaper7/SDM_Energy_Meter

Question about what RS485 converter to use

panbak opened this issue · 3 comments

panbak commented

Hello and thank you for your work.
It is unclear for me what module I should use to make this work. Is any of the modules shown to links bellow compatible to use with your library for my ESP32 project?

TTL to RS-485

UART Serial Port to RS485

Thank you and sorry if my question is irrelevant with the library.

reaper7 commented

Hi!
The second module on your list looks similar to mine,
according to the description, it has automatic flow control...
so it can be connected with four wires(+,-.TX,RX), the first module requires five wires (+,-.TX,RX,FLOWCONTROL).

The second module also has two LEDs, helpful in diagnostics.

...but the decision is yours :)

  • ❤️1
panbak commented

Thank you for the fast reply!

I know this is not stack overflow but could validate that my code looks good? I have set the correct baud rate for the ddm18sd power meter (in SDM_Config_User.h) and the slave id is 9. I am currently using the module with no automatic flow control and I control the flow from GPIO4.

#include <SDM.h>                                                                

SDM sdm(Serial1, SDM_UART_BAUD, 4, SERIAL_8N1, SDM_RX_PIN, SDM_TX_PIN);                                                                          //for SWSERIAL


void setup() {
  Serial.begin(115200); 
  sdm.begin();
}

void loop() {
  char bufout[10];
  sprintf(bufout, "%c[1;0H", 27);
  Serial.print(bufout);

  Serial.print("Voltage:   ");
  Serial.print(sdm.readVal(DDM_PHASE_1_VOLTAGE, 0x09), 2);                            //display voltage
  Serial.println("V");

  Serial.print("Current:   ");
  Serial.print(sdm.readVal(DDM_PHASE_1_CURRENT, 0x09), 2);                            //display current
  Serial.println("A");

  Serial.print("Power:     ");
  Serial.print(sdm.readVal(DDM_PHASE_1_POWER, 0x09), 2);                              //display power
  Serial.println("W");

  Serial.print("Frequency: ");
  Serial.print(sdm.readVal(DDM_FREQUENCY, 0x09), 2);                                  //display frequency
  Serial.println("Hz");

  delay(1000);                                                                  //wait a while before next loop
}