Another DIY project:
I always wanted a reference clock. With an easy to read analog clock face.
And it had to be accurate. A LeoNTP comes close.
I've got a GPS receiver with PPS output so why not connect those pulses to the stepper of an ordinary quartz clock?
Garmin guaranteed the PPS pulses to be accurate to within 1 µs. And if I hard wire those to the stepper, the second hand moves within 1 µs of the start of every second. Always.
I still need a small Arduino Nano to create positive and negative pulses, but it is not in the signal's path.
The wall clock was the nastiest I could find in a hardware shop. To see if I would burn out its coil, before I get something fancier. Soldering wires to the coil is not that bad, just pick the soldering points on the board.
Obviously I've got the receiver in a good spot on the roof so I can always guarantee a good reception.
So far so good.