graphite.pde

#include <Bounce.h>

int anaPin = 5; // Analogue in pin
int button = 2; // button pin
int beepPin = 3; // piezo buzzer

// edges of our calibration window
float aMax;
float aMin;

float anIn, scaledValue; // actual analogue input value and the scaled value
int calibrationMode; // are we in calibration mode or normal? calibrationMode == 1 when in calibration mode
Bounce bb = Bounce(button,0.01); // a Bounce object to debounce the push button

void setup() {
  Serial.begin(9600);
  pinMode(button,INPUT);
  pinMode(beepPin,OUTPUT);
  calibrationMode = 1;  
}

void calibrate() {
  if (anIn != 0) { // don't calibrate when no current running through graphite
    if (anIn > aMax) {
      aMax = anIn;
    }
    if (anIn < aMin) {
      aMin = anIn;
    }
    /*
    Serial.print(anIn);
    Serial.print(", ");
    Serial.print(aMin);
    Serial.print(" - ");
    Serial.println(aMax);
    */
    noTone(beepPin);

  } 
}

void oneBeep(int pitch) {
  tone(beepPin, pitch);       
  delay(100);
  noTone(beepPin);
  delay(50);
  
}  
void doubleBeep(int pitch) {
  oneBeep(pitch);
  oneBeep(pitch);
  oneBeep(pitch);
}

void loop() {
   anIn = analogRead(anaPin);

   // button handler
   bb.update();
   if (bb.risingEdge()) {
     if (calibrationMode == 0) {
       aMax=-9999; 
       aMin=9999; 
       doubleBeep(400);
       calibrationMode = 1;
     } else {
       calibrationMode = 0;
       doubleBeep(200);
     }
   }
   
   if (calibrationMode) {
     calibrate();
     scaledValue = -1;
   } else {
     scaledValue = map(anIn,aMin,aMax,50,1200);   
     if (anIn != 0) {
       tone(beepPin, scaledValue);       
       Serial.print("[");
       Serial.print(scaledValue);
       Serial.println("]");
       delay(10);
     } else {
       noTone(beepPin);
     }
   }
}