Read ADC 3 channel

/* readADC custom
 * 09Februri2016
 * @bambangSud
 * tepat di ulang tahun pernikahan kami yang ke 38
 * post: 5 Jan 2017
 */




#define ADC_VREF_TYPE 0x40
int value;
float inputVoltage;
float SUHU;
// Read the AD conversion result
unsigned int read_adc(unsigned char adc_input)
{
  ADMUX = adc_input | (ADC_VREF_TYPE );
  // Delay needed for the stabilization of the ADC input voltage
  delayMicroseconds(10);
  // Start the AD conversion
  ADCSRA |= 0x40;
  // Wait for the AD conversion to complete
  while ((ADCSRA & 0x10) == 0);
  ADCSRA |= 0x10;
  return ADCW;
}

void setup() {
  // put your setup code here, to run once:
  ADMUX = ADC_VREF_TYPE & 0xff;
  ADCSRA = 0x84;
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  value = read_adc(0);
  delay(100);
  value = read_adc(0);
  inputVoltage = (float)value * 500 / 1023;
  Serial.print("adc0: "); Serial.println(inputVoltage);
  delay(500);

  value = read_adc(1);
  delay(100);
  value = read_adc(1);
  inputVoltage = (float)value * 500 / 1023;
  Serial.print("adc1: "); Serial.println(inputVoltage);
  delay(500);

  value = read_adc(2);
  delay(100);
  value = read_adc(2);
  inputVoltage = (float)value * 500 / 1023;
  Serial.print("adc2: "); Serial.println(inputVoltage);
  Serial.println();

  delay(1000);

}