Connect the module to the electronic brick basic board using the analog interface. Put the alternating current wire through the hole of the current transformer. The SIG pin will output a alternating voltage based on the alternating current being measured. You can measure the value using ADC. const int sensorPin = A0; // pin that the sensor is attached to int sensorValue; int time=1; float current; float effective_value; void setup() { Serial.begin(115200); } void loop() { int sensorMax = 0; while (millis() sensorMax) { sensorMax = sensorValue; } } time++; current=(float)sensorMax/1024*5/800*2000000; effective_value=current/1.414; Serial.println("The amplitude of the current is(in mA)"); Serial.println(current, 1); Serial.println("The effective value of the current is(in mA)"); Serial.println(effective_value, 1); }