/* Read Encoder Direction
 * by DojoCorp <http://www.0j0.org>
 *
 * Demonstrates how to detect the direction
 * towards which a motor spins through using
 * a two lines encoder. The testing procedure
 * is to:
 * - press pushbutton 1 on the board to start the test
 * - make the encoder spin by hand
 * - press pushbutton 1 on the board to stop the test
 * - read the result on the serial port configured at 9600 
 *
 * - by the end of the test, button 2 will restart
 *
 * Description of the pinout used by the motor control board:
 * - digital pin 39 reads pushbutton 1
 * - digital pin 38 reads pushbutton 2
 * - digital pin 0 reads encoder's input A (we just need one encoder line) 
 * - digital pin 1 reads encoder's cross by zero (not used) 
 * - digital pin 4 reads encoder's input B (not used) 
 *
 * Created 25 March 2005
 */
 
int encoderA = 0;                         // pin 0 is the encoder's line A
int encoderCross = 1;                     // pin 1 is the encoder's cross by zero
int encoderB = 4;                         // pin 4 is the encoder's line B
int inB = 38;                             // reads the pin 38 as a pushbutton (pushbutt 2)
int inA = 39;                             // reads the pin 39 as a pushbutton (pushbutt 1)
boolean testing = false;                  // memorize if we are in the testing process
int ledpin = 48;                          // show the status on while testing, off otherwise
int lastState = LOW;                      // monitor last state of the measuring pin
int state = LOW;                          // monitor current state of the measuring pin

void setup() {
   pinMode(inA, INPUT); 
   pinMode(inB, INPUT); 
   pinMode(encoderA, INPUT); 
   pinMode(encoderCross, INPUT); 
   pinMode(encoderB, INPUT); 
   pinMode(ledpin, OUTPUT); 
   beginSerial(9600);
   printMode(SERIAL);
   print("Start Program \n\r");
   print("Verbose Active \n\r");
}

void loop() {

   // Waits until button 1 pressed to start the test
   while (!testing) {
      if (digitalRead(inA) == HIGH) {
         testing = true;
      }
      delay(100);
   }
   
   // Test starts, counting steps in the encoder
   print("Start Test \n\r");
   digitalWrite(ledpin, HIGH);
   
   while (testing) {
      state = digitalRead(encoderA);
      if ((state == HIGH) && (lastState == LOW)) {
         // only if there is a transition from low to high
         if (digitalRead(encoderB) == HIGH) {
            print("Rotating in direction 1");
         } else {
            print("Rotating in direction 2");
         } 
      }
      lastState = state;

      if (digitalRead(inA) == HIGH) {
         testing = false;
      }
      delay(50); // this time value is our temporal resolution
   }
   
   // Final info
   print("Test if finished \n\r");
   digitalWrite(ledpin, LOW);
   print("Press button 2 to repeat \n\r");

   while (digitalRead(inB) == LOW) {
      delay(100);
   }
}