UART / SERIAL to MQTT

[DanBendavid]

I am using a Arduino Nano to measure 3 CT sensors. A Serial (@ 115200 baud) message is generated by the nano as following : "MSG:2565, Vrms:232.56, P1:565, E1:456, P2:565, E2:456, P3:565, E3:456"

I would like to see a Esp8266 or Esp32 being able to generate the MQTT message. Connection between Nano and Esp is done via RX-> TX and TX->RX (with 3.3V shift ).

Thank you

[DanBendavid]

Hello, Here is a piece of code that can be helpfull function to get the serial

#define EMONTX_PORT Serial

boolean input_get(JsonDocument &data) { boolean gotLine = false; boolean gotData = false; String line;

if(input_string.length() > 0) { line = input_string; input_string = ""; gotLine = true; } // If data received on serial else if (Serial.available()) { // Could check for string integrity here line = Serial.readStringUntil('\n'); gotLine = true; }

if(gotLine) { // Get rid of any whitespace, newlines etc line.trim();

int len = line.length();
if(len > 0) 
{
  DEBUG.printf_P(PSTR("Got '%s'\n"), line.c_str());

  for(int i = 0; i < len; i++)
  {
    String name = "";

    // Get the name
    while (i < len && line[i] != ':') {
      name += line[i++];
    }

    if (i++ >= len) {
      break;
    }

    // Get the value
    String value = "";
    while (i < len && line[i] != ','){
      value += line[i++];
    }

    
    if(name.length() > 0 && value.length() > 0)
    {
      // IMPROVE: check that value is only a number, toDouble() will skip white space and and chars after the number
      data[name] = value.toDouble();
      gotData = true;
    }
  }
}

}

// Append some system info if(gotData) { data[F("freeram")] = ESPAL.getFreeHeap(); data[F("srssi")] = WiFi.RSSI(); data[F("psent")] = packets_sent; data[F("psuccess")] = packets_success;

last_datastr.clear();
serializeJson(data, last_datastr);

}

return gotData; }

void loop {

// handle connections ....

StaticJsonDocument<512> data; boolean gotInput = input_get(data);

if(gotInput) {
  event_send(data);
}

}

void event_send(String &json) { StaticJsonDocument<512> event; deserializeJson(event, json); event_send(event); }

void event_send(JsonDocument &event) { mqtt_publish(event); }

[DanBendavid]

@1technophile Florian, I am currently trying to copy/adapt the RS232 template. Not yet succeeded

[1technophile]

ok, if you have questions, do not hesitate.

[DanBendavid]

Hereby my implementation : The RS232 works fine at 9600baud from Arduino Nano to Gateway. All messages captured, super reliable. I have not tried to do the MQTT to Arduino (it could be interesting to recalibrate the Emon) In the Arduino Nano Emon I have this Serial Print : Serial.print(F("0"));// The prefix for the Serial message

Serial.print(F("{\"Msg\" : ")); Serial.print(emontx.Msg);
Serial.print(F(", \"Vrms\": ")); Serial.print(emontx.Vrms*0.01);

if (CT1) { Serial.print(F(",\"CT1\":{\"RealPower\": ")); Serial.print(emontx.P1); }
if (CT1) { Serial.print(F(", \"Wh\": ")); Serial.print(emontx.E1); }

if (CT2) { Serial.print(F("}, \"CT2\":{\"RealPower\": ")); Serial.print(emontx.P2); }
if (CT2) { Serial.print(F(", \"Wh\": ")); Serial.print(emontx.E2); }

if (CT3) { Serial.print(F("}, \"CT3\":{\"RealPower\": ")); Serial.print(emontx.P3); }
if (CT3) { Serial.print(F(", \"Wh\": ")); Serial.print(emontx.E3); }

Serial.print(F("} }"));

Then in the OpenGateway, hereby my parameters :

Config_RS232.h

//Setup for RS232 #define MAX_INPUT 300 // how much serial data we expect #define RS232Baud 9600 // The serial connection Baud #define RS232Pre "00" // The prefix for the RS232 message #define RS232Post "\n" // The postfix for the RS232 message #define RS232InPost '\r' // Hacky way to get last character of postfix for incoming

I have added in ZgatewayRS232.ino : #include "config_RS232.h" #include <ArduinoLog.h>

dont know why it was working without

[1technophile]

Would you want to submit a PR with your work?

[DanBendavid]

Hi all, One month after,the gateway is very reliable . Thank you so much Florian (@1technophile ) for this fabulous job.
The can probably do a PR for the next release and use the Config_RS232.h parameters as default and to add the 2 lines in ZgatewayRS232.ino

[1technophile]

Nice, thanks for the feedback!