#define MotorPin 10
int val;
long last=0;
int stat=LOW;
int stat2;
int contar=0;
double MotorSpeed =0;
int thisTime =0;
int delayTime = 500;
int sens=457; // this value indicates the limit reading between dark and light,
// it has to be tested as it may change acording on the
// distance the leds are placed.
int nPalas=2; // the number of blades of the propeller
int milisegundos=1; // the time it takes each reading
void setup()
{
Serial.begin(9600);
pinMode(13,OUTPUT);
pinMode (MotorPin,OUTPUT);
analogWrite (MotorPin,100);
}
void loop()
{
val=analogRead(0);
if(val<sens)
stat=LOW;
else
stat=HIGH;
digitalWrite(13,stat); //as iR light is invisible for us, the led on pin 13
//indicate the state of the circuit.
if(stat2!=stat){ //counts when the state change, thats from (dark to light) or
//from (light to dark), remmember that IR light is invisible for us.
contar++;
stat2=stat;
}
if(millis()-last>=milisegundos){
double rps=((double)contar/nPalas)/2.01000.0/milisegundos;
double rpm=((double)contar/nPalas)/2.060000.0/(milisegundos);
Serial.print((contar/2.0));Serial.print(" RPS ");Serial.print(rps);
Serial.print(" RPM");Serial.print(rpm);Serial.print(" VAL ");Serial.println(val);
contar=0;
last=millis();
}
}