fancart.pde

// Fan cart driver
// Eric Ayars
// 6/16/10

#define MOTORDRIVE 10
#define MOTORINDICATOR 13
#define SELECTSWITCH 11
#define REEDSWITCH 12
#define POWER1 7
#define POWER2 8
#define POWER3 9 
#define DEBOUNCE 100

byte PowerSetting = 2;	// Ranges from 0 to 3
byte PowerLevel[] = {0, 130, 200, 255};
int MotorState = 0;
byte LastInputState = HIGH;
byte LastReedState = HIGH;

boolean ButtonPressed() {
	boolean state;
	byte CurrentState = digitalRead(SELECTSWITCH);
	if ((LastInputState == HIGH) && (CurrentState == LOW)) {
		// button has just been pressed
		state = true;
		delay(DEBOUNCE); 
	} else {
		state = false;
	}
	LastInputState = CurrentState; 
	return state;
}
	
boolean MagnetSensed() {
	boolean state;
	byte CurrentState = digitalRead(REEDSWITCH);
	if ((LastReedState == HIGH) && (digitalRead(REEDSWITCH) == LOW)) {
		// Cart has just passed a magnet
		state = true;
		delay(DEBOUNCE);
	} else {
		state = false;
	}
	LastReedState = CurrentState;
	return state;
}

void setup() {

	// Set appropriate pins to output
	pinMode(MOTORINDICATOR, OUTPUT);
	pinMode(POWER1, OUTPUT);
	pinMode(POWER2, OUTPUT);
	pinMode(POWER3, OUTPUT);

	// Turn off motor, just in case
	analogWrite(MOTORDRIVE, 0);
	digitalWrite(MOTORINDICATOR, LOW);
	
	// Set input pins
	pinMode(SELECTSWITCH, INPUT);
	pinMode(REEDSWITCH, INPUT);
}

void loop() {
	
	// Check status of "user interface"
	if (ButtonPressed()) {
		PowerSetting += 1;
		if (PowerSetting > 3) {
			PowerSetting = 0;
		}
	}

	// Check status of reed switch
	if (MagnetSensed()) {
		// Toggle between 0 and 1
		MotorState = -MotorState + 1;
	}

	// Turn on appropriate lights 
		if (PowerSetting > 0) {
			digitalWrite(POWER1, LOW);
		} else {
			digitalWrite(POWER1, HIGH);
		}
		if (PowerSetting > 1) {
			digitalWrite(POWER2, LOW);
		} else {
			digitalWrite(POWER2, HIGH);
		}
		if (PowerSetting > 2) {
			digitalWrite(POWER3, LOW);
		} else {
			digitalWrite(POWER3, HIGH);
		}
	
	// Set motor state
	if (MotorState) {
		analogWrite(MOTORDRIVE, PowerLevel[PowerSetting]);
		digitalWrite(MOTORINDICATOR, HIGH);
	} else { 
		analogWrite(MOTORDRIVE, 0);
		digitalWrite(MOTORINDICATOR, LOW);
	}
}