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Hello everybody,

I have non invasive current sensor TA12-100

I found only one sketch for this sensor

/****************************************************************************/
// Function: Measure the amplitude current of the alternating current and
// the effective current of the sinusoidal alternating current.
// Hardware: Grove - Electricity Sensor
// Date: Jan 19,2013
// by www.seeedstudio.com
#define ELECTRICITY_SENSOR A1 // Analog input pin that sensor is attached to
float amplitude_current; //amplitude current
float effective_value; //effective current
void setup() {
  Serial.begin(9600);
  pins_init();
}
void loop() {
  int sensor_max;
  sensor_max = getMaxValue();
  Serial.print("sensor_max = ");
  Serial.println(sensor_max);
  //the VCC on the Grove interface of the sensor is 5v
  amplitude_current=(float)sensor_max/1024*5/200*1000000;
  effective_value=amplitude_current/1.414;
  //minimum_current=1/1024*5/800*1000000/1.414=8.6(mA)
  //Only for sinusoidal alternating current
  Serial.println("The amplitude of the current is(in mA)");
  Serial.println(amplitude_current,1);
  //Only one number after the decimal point
  Serial.println("The effective value of the current is(in mA)");
  Serial.println(effective_value,1);
}
void pins_init(){
  pinMode(ELECTRICITY_SENSOR, INPUT);
}
/*Function: Sample for 1000ms and get the maximum value from the SIG pin*/
int getMaxValue(){
  int sensorValue; //value read from the sensor
  int sensorMax = 0;
  uint32_t start_time = millis();
  while((millis()-start_time) < 1480)//sample for 1000ms
  {
    sensorValue = analogRead(ELECTRICITY_SENSOR);
    if (sensorValue > sensorMax)
    {
      /*record the maximum sensor value*/
      sensorMax = sensorValue;
    }
  }
  return sensorMax;
}

But the results of measurements is incorrect. For crosscheck i'm using energy meter.

When on energy meter current is 0.57A on com port shows

sensor_max = 80
The amplitude of the current is(in mA) 1953.1
The effective value of the current is(in mA) 1381.3

When on energy meter 11.27A on com port shows

sensor_max = 1023
The amplitude of the current is(in mA) 24975.6
The effective value of the current is(in mA) 17663.1

What should I do to get right figures?

Or it is better to use EmonLib?

Thank you in advance for your help