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)
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.