Yonas Leguesse
Published

Spark Non-Invasive Smart Electricity Meter

A simple Non-Invasive Smart Electricity Meter using Spark Core

Full instructions provided18,240
Spark Non-Invasive Smart Electricity Meter

Things used in this project

Hardware components

Non Invasive current sensor (CT sensor YHDC SCT-013-000 )
×1
Burden resistor 18 Ohms
×1
10k Ohm resistors
×2
10uF capacitor
×1

Story

Read more

Code

file_10981.txt

C/C++
The project uses the EmonLib Library for Electricity monitoring  https://github.com/openenergymonitor/EmonLib
// This #include statement was automatically added by the Spark IDE.

#include "HttpClient/HttpClient.h"
#include "application.h"
#include "EmonLib.h"
#include <string.h>

HttpClient http;
http_request_t request;
http_response_t response;
http_header_t headers[] = {

      { "Content-type", "application/x-www-form-urlencoded" },
    { NULL, NULL } // NOTE: Always terminate headers will NULL
};

EnergyMonitor emon1;                   // Create an instance
TCPClient client;
const int voltage = 220;
double average = 0.0; // interval at which to do something (millisecond)
double sum = 0.0; // interval at which to do something (milliseconds)
int count = 0; // interval at which to do something (milliseconds)

static unsigned long secondInterval = 1000;
static unsigned long minuteInterval = 57000;
static unsigned long prevMinute = 0;
static unsigned long prevSecond = 0;
unsigned long now;

void setup()
{  
  Serial.begin(9600);         
  emon1.current(0, 103.1);           
}



void loop()

{
   unsigned long currentMillis = millis();
    if ((unsigned long)(currentMillis - prevSecond) < secondInterval){
    return;
        }
    else{

        double Irms = emon1.calcIrms(1480);  // Calculate Irms only
        //double watts = (Irms*voltage) - 16;  // Calculate Irms only
        double watts = (Irms*1000) ;  // Calculate Irms only
        sum = sum + watts;
        count = count + 1;
        if ((unsigned long)(currentMillis - prevMinute) < minuteInterval){
        return;
        }
        else{
            average = sum/count;
            sendWatts(average);
            average = 0.0;
            sum = 0.0;
            count = 0;
            prevMinute = currentMillis;
        }
        prevSecond = currentMillis;
        }
}

void sendWatts(double wattreading){
    String val = "watts=" + doubleToString(wattreading,2);
    request.hostname = "yourhost.com";
    request.port = 80;
    request.path = "/php/insertConsumption.php";
    request.body = val ;
    http.post(request, response, headers);
}


String doubleToString(double input,int decimalPlaces){
    if(decimalPlaces!=0){
    String string = String((int)(input*pow(10,decimalPlaces)));
    if(abs(input)<1){
    if(input>0)
    string = "0"+string;
    else if(input<0)
    string = string.substring(0,1)+"0"+string.substring(1);
    }

    return string.substring(0,string.length()-decimalPlaces)+"."+string.substring(string.length()-decimalPlaces);

    }
    else {
    return String((int)input);
    }

}

file_13723.php

PHP
insertConsumption.php
<?php



include_once('IConnectInfo.php');



$link = mysql_connect(IConnectInfo::HOST, IConnectInfo::UNAME, IConnectInfo::PW)

or die('Could not connect: ' . mysql_error());

//echo "Connected successfully \n";

mysql_select_db(IConnectInfo::DBNAME) or die('Could not select database');



  	

 if(isset($_POST['watts']) ) {

   if(ctype_digit($_POST['watts']) && is_int($_POST['watts'])) {

   	$poswatts = $_POST['watts']; 

  	if($poswatts<0 ) $poswatts  = 0;

          date_default_timezone_set("UTC"); 

          $currutctime = date("Y-m-d H:i:s", time());

  

      $pdo = new PDO('mysql:store.db');

      $stmt = $pdo->prepare('INSERT INTO Consumption (watts,unixtime)   VALUES (:watts, :unixtime);');

      $stmt->bindParam(':watts', $poswatts, PDO::PARAM_INT);

      $stmt->bindParam(':unixtime', $currutctime, PDO::PARAM_STR);

      $stmt->execute();

  

  		} else {

      // reject id value and report error to user

    }

	}

 

?>





 

file_12188.php

PHP
insertConsumption.php - (w/o input validation) -
 <?php



include_once('IConnectInfo.php');



$link = mysql_connect(IConnectInfo::HOST, IConnectInfo::UNAME, IConnectInfo::PW)

or die('Could not connect: ' . mysql_error());

//echo "Connected successfully \n";

mysql_select_db(IConnectInfo::DBNAME) or die('Could not select database');



  	

 // varying values

 if(isset($_POST['watts']) ) {

 	$poswatts = $_POST['watts']; 

	if($poswatts<0 ) $poswatts  = 0;

        date_default_timezone_set("UTC"); 

        $currutctime = date("Y-m-d H:i:s", time());

 	$sql = 'INSERT INTO Consumption '.

 			'(watts,unixtime) '.

 			'VALUES ( '. $poswatts .', "'. $currutctime .'");';

	 	$result = mysql_query($sql) or die('Query failed: ' . mysql_error());

	 	echo("success-" .mysql_insert_id());

	 	//mysql_free_result($result);

	 	mysql_close($link);

	 	//echo($result);

 }

 

?>





                            

Credits

Yonas Leguesse

Yonas Leguesse

5 projects • 42 followers

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