hall_effect.ino

#define NOFIELD 505L    // Analog output with no applied field, calibrate this

// Uncomment one of the lines below according to device in use A1301 or A1302
// This is used to convert the analog voltage reading to milliGauss
#define TOMILLIGAUSS 1953L  // For A1301: 2.5mV = 1Gauss, and 1024 analog steps = 5V, so 1 step = 1953mG
// #define TOMILLIGAUSS 3756L  // For A1302: 1.3mV = 1Gauss, and 1024 analog steps = 5V, so 1 step = 3756mG

int ticks = 0;
unsigned long time_e;

void setup() 
{
  Serial.begin(9600);
  time_e = millis();
}

long DoMeasurement()
{
// measure magnetic field
  int raw = analogRead(0);   // Range : 0..1024

//  Uncomment this to get a raw reading for calibration of no-field point
//  Serial.print("Raw reading: ");
//  Serial.println(raw);

  long compensated = raw - NOFIELD;                 // adjust relative to no applied field 
  long gauss = compensated * TOMILLIGAUSS / 1000;   // adjust scale to Gauss

  //Serial.print(gauss);
  //Serial.print(" Gauss ");

  //if (gauss > 0)     Serial.println("(South pole)");
  //else if(gauss < 0) Serial.println("(North pole)");
  //else               Serial.println();
  return gauss;
}

void loop() 
{
   long measure_1 = DoMeasurement();
   delay(100);
   long measure_2 = DoMeasurement();
   if(measure_1 < 0 && measure_2 > 0)
   {
       ticks++;
   }
   Serial.print("Número vueltas: ");
   Serial.print(ticks);
   Serial.print("Tiempo");
   Serial.print(time_e-millis())
}