//MEEM1803 Assignment 1: Reading encoder RPM using push button
//Darren Tan (MEE221009), Jiang Haoyu (MEE221006)
//The push button is used to represent the encoder reading
#define button1 27 //Define push button as digital pin 27
int counter1;
int speed1;
const long interval = 1000;
const long interval1 = 100;
unsigned long previousMillis = 0; 
unsigned long currentMillis = 0;
unsigned long previousMillis1 = 0;

void setup()
{
  Serial.begin(115200);
  pinMode(button1, INPUT); //Set push button as input
  attachInterrupt(button1, detect, RISING); //Detact the rising edge of push button
}

void detect()
{
  // Counter the pulse and add to main counter
  if (currentMillis-previousMillis1>=interval1)
  {
    counter1++;
    previousMillis1 = currentMillis;
  }
  
}
void loop()
{
  currentMillis=millis();
  if(currentMillis-previousMillis>=interval) //
  {
    // To calculate speed of wheel rotate
    speed1 = counter1*60;     //RPM = ((Total pules/Pulse per rotation)/sec) * 60
    Serial.print(speed1);    //Print the speed in Serial Monitor
    Serial.println(" Rotation per Minute");
    previousMillis = currentMillis;
    counter1 = 0;            // To default and intialize the counter
  }
  
}