12-hour clock, cannot be armed more than 11.5 hours before
alarm time,
triggers at plus or minus ten minutes, depending on how it was dropped,
battery cover needs to be removed to change time,
changing time at daylight saving loses minutes and seconds,
immitated by rural birdlife, causing false triggers,
second hand has failed from repeated dropping,
closed source implementation.
New Alarm Clock Features
wakes Quozl up each day,
doesn't wake Quozl's wife,
defaults to wake Quozl up the next day, doesn't need to be told,
can be told at any time in the previous day not to wake Quozl up,
can be configured accurately without having to hold buttons down,
can emit per-second tick noises, or not,
can emit tones in response to key presses, or not,
can be told that Quozl is on holidays,
changing time for daylight saving can retain minutes and seconds,
open source, capable of being further hacked.
Not yet features
automatic daylight saving transitions,
gradual daylight saving alarm time shifts,
weekend alarm suppression,
recording of how long it took to wake Quozl up,
serial port for GUI configuration,
synchronisation using NTP or rdate over PPP or SLIP,
Top Level Design
Schematic
This project was built using a Dontronics DT106A PCB, with a PIC
16F877. If you wish to recreate this device, start with Don's page
for the DT106, at http://dontronics.com/dt106.html,
he has schematics and assembly instructions. There were no
significant modifications to his PCB, but there was a change in how
the LCD connections are made, so that the keyboard could be
scanned.
Prototype Photographs
The prototype was built into a plastic tape box, in the shape of a
paperback book. It suits mounting vertically on a stand.