This is a simple hand held iButton reader for collecting results after a small event, to dispense with the need for a PC on-site.

It displays the competitors run-time, and control order with split times so the results can be copied to a paper list.  The ibuttons can be read again later with a PC, at home,  for web publishing etc.

Features are somewhat limited by the 2k byte limit of the 16F628 and  the free-to-use PIC Mikro-basic compiler, but it still works great.

If you move to a 16F648 , which has 4k available for the program, then you will have to pay for the full compiler !

Schematic below :-

Reader software can be downloaded  here.