getSensorValues ACS712 - not working

arduino-acs712

void getSensorValues(){
  unsigned long currentAcc = 0;
  unsigned int count = 0;
  unsigned long prevMicros = micros() - sampleInterval ;
  while (count < numSamples)
  {
    if (micros() - prevMicros >= sampleInterval)
    {
      int adc_raw = analogRead(0) - adc_zero;
      currentAcc += (unsigned long)(adc_raw * adc_raw);
      ++count;
      prevMicros += sampleInterval;
    }
  }
  
    float rms = sqrt((float)currentAcc/(float)numSamples) * (75.7576 / 1024.0);
    mySerial.println(rms);
}