Arduino Thumbstick

gistfile1.c

ThumbState_t thumbSt;

const bool DEBUG = false;  // set to true to debug the raw values

int xPin = A2;
int yPin = A3;
int xZero, yZero;
int xValue, yValue;
int deadzone = 5;  // smaller values will be set to 0

void setup(){
 	pinMode(xPin, INPUT);
 	pinMode(yPin, INPUT);

 	if(DEBUG) {
 		Serial.begin(9600);
 	}

	// calculate neutral position
	xZero = analogRead(xPin);
	yZero = analogRead(yPin);

	thumbSt.xAxis = 0;
	thumbSt.yAxis = 0;
}

void loop(){
	xValue = analogRead(xPin) - xZero;
	yValue = analogRead(yPin) - yZero;

	if(abs(xValue) < deadzone) {
		xValue = 0;
	}
	if(abs(yValue) < deadzone) {
		yValue = 0;
	}

	thumbSt.xAxis = map(xValue, 400, -400, -32768, 32768);  // here the axis is inverted
	thumbSt.yAxis = map(yValue, -400, 400, -32768, 32768);

 	if(DEBUG) {
 		Serial.print("X: ");
		Serial.println(xValue);
 		Serial.print("Y: ");
		Serial.println(yValue);
	}

	// Send to USB
	Thumbstick.setState(&thumbSt);
}