//
// We remove part of the plastic from a cheap battery powered quartz clock
// to expose the two wires of the motor coil. We then solder long wires to these
// exposed motor terminals so we can connect them to Port 1 pin 4 and Port 1 pin 5.
// Now we remove the battery from the clock, and use the Launchpad to send the
// signals to the coil instead of the normal clock electronics.
//
// This lets us run the clock at high speed, or at much lower speeds if we like.
//
// To get an approximation to real time, a delay of 1,000 milliseconds (one second)
// would be close. For truly quartz-accurate timing, solder the crystal onto the board,
// and use a timer set for one second intervals. You can do the XOR in an interrupt routine.
//
// Some clocks will only run as fast as 240 milliseconds per tick before they get totally
// confused (some really cheap $2.88 Walmart clocks I tried). The $25 Staples wall clock,
// which seems to have the same movement as Westclock clocks do, can run with a 20 millisecond
// period (50 times faster than normal time). But sometimes they start up going backwards
// when run that fast, and sometimes they don't start.
//
// I don't know why the clocks like to run clockwise, but presumably they are designed to
// do that reliably. That they can run backwards was a pleasant surprise, and it may be
// that pushing the second hand backwards by hand might get them to do that. I have yet
// to remove the front face and try that.
//
// With the big Staples wall clock, I can run it with a 20 millisecond period and get it
// to run backwards about 1/5th of the time. I just keep hitting the RESET button on the
// Launchpad until it's running backwards.
//

void
setup( void )
{
  P1DIR = 0b110000;
  P1OUT = 0b100000;
}

void
loop( void )
{
  P1OUT ^= 0b110000;
  delay( 25 );
}