Recently I attended a toastmasters meeting where speeches are timed and the speaker is shown a green, yellow, red or no light to indicate the usage of their allotted time. It may be obvious by now that I thought I could improve on the timing methods being used. The catch was, I didn’t tell anyone that I was going to build this system.
Notable features include:
- Automatic or manual modes
- Brightness control of the LEDs
- Timing accuracy within one second per hour
- Event driven program, providing instant feedback to changes
- Some power usage consideration for battery operation
- User manual (bottom of page)
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Timing accuracy is achieved using the hardware counter inside the micro controller (uC) for timing.
Power usage was improved by bypassing the uC’s linear regulator and adding a buck converter for 9v battery usage.