A servo, a little code, and a clock for geeks was
born. What geek could resist reading the time on a large
analog meter? And it's great for clock-watching without
This project actually led to the TAP-28 board. Cool
as this is, it doesn't justify sacrificing a full-featured
development board. The first iteration of the clock used a
hand-built perf board circuit but the following copies use TAP-28
boards. Their low cost, particularly with minimal parts
installed on the TAP-28 make these clocks practical. The
two buttons on the TAP-28 provide all the user interface needed
to set the clock.
The "production" clocks use an 18F242 with a 20
MHz crystal; the time base is derived from the crystal.
For details, check out these links:
First Clock Construction
Improved Calibration Method
Required For Low-Cost Servo
Swordfish Basic Source code and build details can be found at the above links.