I have an intermediate knowledge of electronics. I want to design and build a start clock for orienteering events for our local orienteering club. In orienteering the competitors start the race at either 1 or 2 minute intervals, with a start clock which sounds the last 5 seconds of start interval with beeps, the last second (on the minute) being a longer beep.
Other design requirements are:
- low current consumption
- portable and small (6"x4"x2" max???)
- large LCD readout of the seconds and minutes (5 digits, 3 for minutes,
2 for seconds- precise quartz timing
- rugged and weatherproof
I wonder if anyone can point me to reasonably similar start clock designs which I can adapt to my requirements rather than me starting from scratch.
Any assistance greatly appreciated.