// (Worksheet 4-9-1s - Timing  )

// (Worksheet 4-9-1s Number 4)
//  It is likely that your code took longer to draw than you expected.  
//  Modify your system so that it will display a picture in less than 0.25 seconds.
//  Consider changing the stepsize in the loop that controls when each LED is on or off.


// (Worksheet 4-9-1s Number 5)
//  To display the image in the same place each time we need to have a reference point in the rotation.  
//  We will use a Hall-effect sensor that toggles between HIGH and LOW each time the handle turns.
//  First wait for the sensor to be HIGH, then wait for the sensor to go LOW again.  
//  The sensor is connected to an analog pin which has a range from 0 to 1023 (10 bits).  
//  By setting a HIGH threshold of 600 and a LOW threshold of 400 we avoid false triggers as the input slowly moves through the LOW to HIGH transition.  This is called hysteresis. 

//  Create a function called void waitForTrigger() that reads the analog I/O pin connected to the Hall-effect sensor.  
//  Functions should be created outside of any other function definitions.
//  Use analogRead() to get the input value.  You should have defined a reference to the pin earlier
//  Use a first while () loop to wait until the pin is high (value > 600).  
//  Then use a second while() loop to wait until it goes low (<400).

void waitForTrigger(void) {
  while (analogRead(magneticSensor) < 600) {
      // stay here as long as the pin value is less LOW (less than 600).
  }
  while ( ) {// you finish this one.
  
  }
}

// (Worksheet 4-9-1s Number 6)
// Call the waitForTrigger() function at the beginning of your main loop() function.