Lap Timer
College: Electronics, Second Year (2006).
For my A level coursework I produced a lap timer and counter. The general principle was to display the passage of time on seven segment displays (SSDs) and every time a new lap was trigger a lap count would increase and the timer reset. The design for the circuit went well enough but the actual implementation grew to be chaotic. During the course of development I also attempted to add new features that had not been accounted for in the initial design.
The design for the circuit was broken down into sub systems: timer pulse circuit, latch circuits, timer display circuit and switch debouncers. To produce the circuit design I used two software packages. The College provided "Crocodile Clips" and I used "Livewire" in my own time.
Livewire diagram of all the sub systems. Click to view larger version.
Two example videos available on my YouTube account: