#define CLK 2
#define DT 3
unsigned long lastReset;
float N=20;
int counter = 0;
float speed_counter=0;
int currentStateCLK;
int lastStateCLK;
String currentDir ="";
float TP=300;
void setup() {

	// Set encoder pins as inputs
	pinMode(CLK,INPUT);
	pinMode(DT,INPUT);
	// Setup Serial Monitor
	Serial.begin(9600);

	// Read the initial state of CLK
	lastStateCLK = digitalRead(CLK);
	
	// Call updateEncoder() when any high/low changed seen
	// on interrupt 0 (pin 2), or interrupt 1 (pin 3)
	attachInterrupt(0, updateEncoder, CHANGE);
	attachInterrupt(1, updateEncoder, CHANGE);

}

void loop() 
{
  if (millis() - lastReset > TP) 
  {
    lastReset += TP;
    speed_counter=counter;
		float speed;
		speed = 2*3.14*1000*speed_counter/(N*TP);
    Serial.print("Counter is ");
    Serial.print(speed_counter);
		Serial.print("\n");
		Serial.print("Speed is ");
		Serial.print(speed);
    counter = 0;
		Serial.print("\n\n");
  }

}

void updateEncoder(){
	// Read the current state of CLK
	currentStateCLK = digitalRead(CLK);

	// If last and current state of CLK are different, then pulse occurred
	// React to only 1 state change to avoid double count
	if (currentStateCLK != lastStateCLK  && currentStateCLK == 1){

		// If the DT state is different than the CLK state then
		// the encoder is rotating CCW so decrement
		if (digitalRead(DT) != currentStateCLK) {
			counter ++;
			currentDir ="CW";
		} else {
			// Encoder is rotating CW so increment
			counter --;
			currentDir ="CCW";
		}

		Serial.print("Direction: ");
		Serial.print(currentDir);
		Serial.print(" | Counter: ");
		Serial.println(counter);
	}

	// Remember last CLK state
	lastStateCLK = currentStateCLK;
}