Coin Acceptor

/*
  This sketch assumes that coin 1, will return 1 pulse, coin 2 will return 2 pulses, and so on.

 Coin values:
 1 = 0.5
 2 = 1
 3 = 2
 4 = 10
 */

const byte coinValues[4] = {
  5, 10, 20, 100}; //Coin values goes into this array
#define pulseTimeout 200        //How many milliseconds there are from the last impulse to the coin is determined (default 275)
#define actionTimeout 60000     //How many milliseconds before stored credit is reset (default 60000)


unsigned long lastAction = 0;   //When last action was made
unsigned long lastPulse = 0;    //When last pulse was send
int pulseCount = 0;             //How many pulses we got
int currentCredit;              //The current credit

void showCredit()
{
  int credit = currentCredit/10;
  int left = currentCredit % (currentCredit/10);

  Serial.print("Current credit: ");
  Serial.print(credit, DEC);
  Serial.print(".");
  Serial.print(left, DEC);
  Serial.println("0");
}

void setup()
{
  Serial.begin(115200);

  attachInterrupt(0, acceptorCount, RISING); //Digital interrupt pin 1
  attachInterrupt(1, acceptorPulse, RISING); //Digital interrupt pin 2

  Serial.println("Coin Acceptor ready");
  pulseCount = 0;

  pinMode(13, OUTPUT);
}

unsigned long tempAction;
unsigned long tempPulse;

void loop()
{
  tempAction = lastAction;
  tempPulse = lastPulse;

  if (millis() - lastPulse >= pulseTimeout && pulseCount > 0 || pulseCount >= 4)
  {
    if (tempAction != lastAction || tempPulse != lastPulse) return; //Check if interrupt has fired since loop started, wait for next cycle if it has

    tone(12, 1800, 150);
    currentCredit += coinValues[pulseCount-1];
    showCredit();
    pulseCount = 0;
  }


  if ((millis() - lastAction >= actionTimeout) && (lastAction != 0) && (currentCredit > 0) && (pulseCount == 0))
  {
    if (tempAction != lastAction || tempPulse != lastPulse) return; //Check if interrupt has fired since loop started, wait for next cycle if it has

    currentCredit = 0;
    lastAction = 0;
    Serial.println("\n*** TIMEOUT! Credit reset. ***");
    showCredit();
  }
}

void acceptorPulse()
{
  lastAction = millis();
  lastPulse = millis();
  pulseCount++;
}

void acceptorCount()
{
  digitalWrite(13, digitalRead(13));
}