/elec/propeller-clock

//

// propeller-clock.pde

//

// A propeller clock.

void setup()

{

  // set up an interrupt handler on pin 2 to nitice fan pulses

  attachInterrupt( 0, fanPulseHandler, RISING );

  digitalWrite( 2, HIGH );

  // set up output pins (4 to 13) for the led array

  for( int a = 4; a < 14; a++ )

    pinMode( a, OUTPUT );

  // serial comms

  Serial.begin( 9600 );

}

// when non-zero, the time (in microseconds) of a new fan pulse that has just

// occurred, which means that segment drawing needs to be restarted

static unsigned long new_pulse_at = 0;

// interrupt handler to count the number of fan pulses

void fanPulseHandler()

{

  // ignore every other pulse

  static bool ignore = true;

  ignore = !ignore;

  if( !ignore )

  {

    // set a new pulse time

    new_pulse_at = micros();

  }

}

// wait until it is time to draw the next segment or a new pulse has occurred

void endOfSegmentDelay()

{

  while( micros() < next_segment_at && !new_pulse_at );

}

void loop()

{

  static int led = 4;

  unsigned long loop_start_time = micros();

  // wait till it's time to draw the next segment

}