About Calibration

Since the analog reading is affected by the accuracy of the reference voltage. For a more

accurate reading, use a high-precision multimeter to measure the analog reference voltage

of the controller (usually the same as the supply voltage) and modify the #define VREF

5.0 parameter in the sample code below to complete the calibration.

/*!

* @file readACCurrent.

* @n This example reads Analog AC Current Sensor.

* @copyright

Copyright (c) 2010 DFRobot Co.Ltd (https://www.dfrobot.com)

* @licence

The MIT License (MIT)

* @get from https://www.dfrobot.com

Created 2016-3-10

By berinie Chen <bernie.chen@dfrobot.com>

Revised 2019-8-6

By Henry Zhao<henry.zhao@dfrobot.com>

*/

const int ACPin = A2;

//set arduino signal read pin

#define ACTectionRange 20;

//set Non-invasive AC Current Sensor tection range

(5A,10A,20A)

// VREF: Analog reference

// For Arduino UNO, Leonardo and mega2560, etc. change VREF to 5

// For Arduino Zero, Due, MKR Family, ESP32, etc. 3V3 controllers, change VREF to 3.3

#define VREF 5.0

float readACCurrentValue()

{

float ACCurrtntValue = 0;

float peakVoltage = 0;

float voltageVirtualValue = 0;

//Vrms

for (int i = 0; i < 5; i++)

{

peakVoltage += analogRead(ACPin);

//read peak voltage

delay(1);

}

peakVoltage = peakVoltage / 5;

voltageVirtualValue = peakVoltage * 0.707;

//change the peak voltage to the

Virtual Value of voltage

/*The circuit is amplified by 2 times, so it is divided by 2.*/

voltageVirtualValue = (voltageVirtualValue / 1024 * VREF ) / 2;

ACCurrtntValue = voltageVirtualValue * ACTectionRange;

return ACCurrtntValue;

}