1.2.12. fejezet, Fényérzékelés, közeledés érzékelés

const int analogInPin = A0;  // Analog input pin that the LDR is attached to
const int analogOutPin = 9; // Analog output pin that the LED is attached to
 
int sensorValue = 0;        // value read from the pot
int outputValue = 0;        // value output to the PWM (analog out)
 
void setup() {
  // initialize serial communications at 9600 bps:
  Serial.begin(9600);
}
 
void loop() {
  // read the analog in value:
  sensorValue = analogRead(analogInPin);
  // map it to the range of the analog out:
  outputValue = map(sensorValue, 0, 1023, 0, 255);
  // change the analog out value:
  analogWrite(analogOutPin, outputValue);
 
  Serial.print("sensor = ");
  Serial.print(sensorValue);
  Serial.print("\t output = ");
  Serial.print(outputValue);
 
  // unsigned int R1 = 9000;
  // float Vmax = 4.73;
  //float Va0 = (Vmax * (float)R1/(float)(R1+R2));
 
  char buffer[16];
  dtostrf((float)sensorValue,5,2,buffer);
  Serial.print("\t Va0 = ");
  Serial.println(buffer);
 
  delay(2);
}