So after 13 nights (evenings) the device was ready to test. We practice (we even have a non-formal team of friends who gather every week) every Tuesday, but I had to watch over my kid that day (I love him so much!), so I took him with me, and we came by bicycle instead of my XJ6. Weather was shitty, so only 1 other guy showed up (well, then another one came, but I was leaving) and I asked him if he could go in circles and test my contraption. It happens that he made the other stop-watch, so we had a constructive chat on the subject, and then the test begun :

Conclusions are as follows:

* Shitty LED display (oh boy the multiplexing thing almost killed me. It was 50% of the work this display). Not much visible in the direct sun. As I mentioned, I did this at night mostly, so It looked like perfect at home and at dark. But sun (and even partially cloudy weather) made it unreadable. I already found and ordered promisingly looking LCD displays (China of course), which would be much more clear, and less power hungry. Oh boy how I love compulsive purchasing on AliExpress. One click and you're there.

* Too low range. As you could have seen on the vid, the stop-watch comprises of IR emitter with brass pipe attached for beam focusing, and receiver, which has IR remote thing. http://www.farnell.com/datasheets/1734663.pdf Again, in dark it behave well, but outdoors it had problems.

Both receiver and emitter draws about 50mA and has 1000 mAh LiPo batteries.