/*
* ARDUINO NANO
* CON NANO CINESE OLD BOATLOADER
Led emitted R1=2200Ohm
Fotodiodo R2=4700ohm cathod to +5V trhough R2
fotodiodo analog A0 connected
V=5Volt
*/
int pinPD= A0;//analog pin for PhotoDiode
int IRled= 2; //digital pin for lighting IR led D2
int valuePin=0;
float voltage;


void setup() {
Serial.begin(9600);
pinMode(pinPD,INPUT);
pinMode(IRled,OUTPUT);
digitalWrite(IRled,HIGH);
}

void loop() {
valuePin=analogRead(pinPD);
voltage=valuePin*(5.0/1023.0);
Serial.println(valuePin);
Serial.print(" -- ");
Serial.println(voltage);
delay(100); }