P1 reader

/* Arduino 'slimme meter' P1 port reader.

This sketch reads data from a Dutch smart meter that is equipped with a P1 port.
Connect 'RTS' from meter to Arduino +5V
Connect 'GND' from meter to Arduino GND
Connect 'RxD' from meter to Arduino pin 8 (Digital)

Baudrate 115200, 8N1.
BS170 transistor & 10k resistor is needed to make data readable if meter spits out inverted data

A .php file is requested (with consumption numbers in the GET request) everytime a telegram from the meter is received (every 10s)

created 2014
by 'ThinkPad' @ Tweakers.net

http://gathering.tweakers.net/forum/list_messages/1601301
 */

#include <AltSoftSerial.h>
#include <SPI.h>
#include <Ethernet.h>
// AltSoftSerial always uses these pins:
//
// Board          Transmit  Receive   PWM Unusable
// -----          --------  -------   ------------
// Teensy 2.0         9        10       (none)
// Teensy++ 2.0      25         4       26, 27
// Arduino Uno        9         8         10
// Arduino Mega      46        48       44, 45
// Wiring-S           5         6          4
// Sanguino          13        14         12

AltSoftSerial altSerial;

byte mac[] = {
  0xDE, 0xAD, 0xBE, 0x30, 0x32, 0x31};
IPAddress ip(192,168,4,7);
IPAddress server(192,168,4,4);
EthernetClient client;

const int requestPin =  4;
char input; // incoming serial data (byte)
bool readnextLine = false;
#define BUFSIZE 75
char buffer[BUFSIZE]; //Buffer for serial data to find \n .
int bufpos = 0;
long mEVLT = 0; //Meter reading Electrics - consumption low tariff
long mEAV = 0;  //Meter reading Electrics - Actual consumption
long mG = 0;   //Meter reading Gas

void setup() {
  Serial.begin(9600);
  delay(1000);

  altSerial.begin(115200);
  delay(1000);

  Ethernet.begin(mac, ip);
  delay(1000);
  Serial.print("My IP address: ");
  Serial.println(Ethernet.localIP());
  Serial.print("Server IP address: ");
  Serial.println(server);

  pinMode(4, OUTPUT);                  // SD select pin
  digitalWrite(4, HIGH);               // Explicitly disable SD

  //Set RTS pin high, so smart meter will start sending telegrams
  pinMode(requestPin, OUTPUT);
  digitalWrite(requestPin, HIGH);
}

void loop() {

  decodeTelegram();

} //Einde loop

void decodeTelegram() {
  long tl = 0;
  long tld =0;

  if (altSerial.available()) {
    input = altSerial.read();

    char inChar = (char)input;
    // Fill buffer up to and including a new line (\n)
    buffer[bufpos] = input&127;
    bufpos++;

    if (input == '\n') { // We received a new line (data up to \n)
      if (sscanf(buffer,"1-0:1.8.1(%ld.%ld" ,&tl, &tld)==2){
        tl *= 1000;
        tl += tld;
        mEVLT = tl;
        if (mEVLT > 0) {
          Serial.println("*** BEGIN LOOP ***");
          Serial.print("Elektra - meterstand verbruik LAAG tarief: ");
          Serial.println(mEVLT);

        }
      }

      // 1-0:1.7.0 = Electricity consumption actual usage (DSMR v4.0)
      if (sscanf(buffer,"1-0:1.7.0(%ld.%ld" ,&tl , &tld) == 2)
      {
        mEAV = (tl*1000)+tld;
        if (mEAV > 0) {
          Serial.print("Elektra - actueel verbruik (W): ");
          Serial.println(mEAV);
        }
      }

      // 0-1:24.2.1 = Gas (DSMR v4.0) on Kaifa MA105 meter
      if (strncmp(buffer, "0-1:24.2.1", strlen("0-1:24.2.1")) == 0) {
        if (sscanf(strrchr(buffer, '(') + 1, "%d.%d", &tl, &tld) == 2) {
          mG = (tl*1000)+tld;
          Serial.print("Gas - meterstand (liters): ");
          Serial.println(mG);
          Serial.println("");
        }
      }

      // Empty buffer again (whole array)
      for (int i=0; i<75; i++)
      {
        buffer[i] = 0;
      }
      bufpos = 0;

    }

    if (input == '!') {   //uitroepteken geeft einde van telegram aan, dus we gaan data versturen
      httpRequest();
      mEVLT = 0;
      mEAV = 0;
      mG = 0;
      client.stop();
    } //Einde vraagteken detectie

  } //Einde 'if AltSerial.available'

} //Einde 'decodeTelegram()' functie

void httpRequest() {
  // if there's a successful connection:
  if (client.connect(server, 80)) {
    client.print("GET /www/slimmemeter/p1.php?mEVLT=");
    client.print(mEVLT);
    client.print("&mEAV=");
    client.print(mEAV);
    client.print("&mG=");
    client.print(mG);
    client.println(" HTTP/1.1");
    client.println("Host: 192.168.4.4");
    client.println("User-Agent: arduino-ethernet");
    client.println("Connection: close");
    client.println();
    //Request complete; empty recieve buffer
    while (client.available()) { //data available
      char c = client.read(); //gets byte from ethernet buffer
    }
    client.println();
    Serial.println("----------------------------Versturen naar database--------------------------");
    Serial.println("Connection OK!");
    Serial.print("GET /www/slimmemeter/p1.php?mEVLT=");
    Serial.print(mEVLT);
    Serial.print("&mEAV=");
    Serial.print(mEAV);
    Serial.print("&mG=");
    Serial.println(mG);
    Serial.println("-----------------------------------------------------------------------------");
    Serial.println();
    Serial.println("*** EINDE LOOP - Wachten op volgende telegram vanuit slimme meter ***");
  }
  else {
    Serial.println("Connection failed");
    client.stop();
  }
}