Blynk and power electric consumption .
the electric meter emits 1 led pulse for every watt that measure
ATtiny85 detects the Led pulse using a sensor LDR , send to interrupt input of Arduino
sketch calculates the elapsed time between two pulses and calculates the power consumption
in the video we see a more elaborate version (rcwitch,lm35, and power consumption), look at the red widget (enel), that updates itself after a few seconds .
attiny85
LDR sensor
arduino uno
shield w5100
#define BLYNK_PRINT Serial // Comment this out to disable prints and save space
#include <SPI.h>
#include <Ethernet.h>
#include <BlynkSimpleEthernet.h>
#include <SimpleTimer.h>
// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "xxxxxxxxxxxxxxxx";
SimpleTimer timer;
long pulseCount = 0;
//Used to measure power.
unsigned long pulseTime,lastTime;
//power and energy
double power, elapsedkWh;
//Number of pulses per wh - found or set on the meter.
int ppwh = 1; //1000 pulses/kwh = 1 pulse per wh
void setup()
{
Serial.begin(9600);
// KWH interrupt attached to IRQ 1 = pin3
attachInterrupt(1, onPulse, FALLING);
Blynk.begin(auth);
// Setup a function to be called every second
timer.setInterval(1000L, sendUptime);
}
void sendUptime()
{
// You can send any value at any time.
// Please don't send more that 10 values per second.
Blynk.virtualWrite(1, power);
}
void loop()
{
Blynk.run(); // Initiates Blynk
timer.run(); // Initiates SimpleTimer
}
// The interrupt routine
void onPulse()
{
//used to measure time between pulses.
lastTime = pulseTime;
pulseTime = micros();
//pulseCounter
pulseCount++;
//Calculate power
power = (3600000000.0 / (pulseTime - lastTime))/ppwh;
//Find kwh elapsed
elapsedkWh = (1.0*pulseCount/(ppwh*1000)); //multiply by 1000 to pulses per wh to kwh convert wh to kwh
//Print the values.
Serial.print(power,4);
Serial.print(" ");
Serial.println(elapsedkWh,3);
}
