Earlier I wrote about my DIY photogates. They work pretty well but there is always room for improvements. So I added a little 16×2 LCD display to the Arduino setup. That way, you can use the large computer-displayed stopwatch or you can rely on the little LCD. Both work simultaneously and on the same Arduino time base;-) The new sketch is here: gates2
Without the USB power from the computer, you will have to find a different power source, but the Arduino will work with very different ones. I tested four or six AA NiMH packs and a 9V wall-wart. An USB wall-wart which could take a normal A-B USB cable (not a fixed mini-B or Micro-B) would also work.
Our maglev track for the Science Olympiad (the reason for all of this;-) is also ready for first tests;-) It’s 3″ wide (the maximum) and six feet long. The rules only require a four feet long track, but that way there is a `braking room’ on both side. All the way at both ends, a pair of reversed magnets will really slow down the vehicle;-)
A couple of pictures from the current setup;-)
Have fun.
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Thanks for including the arduino sketch, I was able to use an arduino uno with a LCD shield to create a set of gates for SO Maglev testing. It really is a good low cost way to obtain times for this event.
Glad it helped you;-) Have fun.
Hey what magnets did you use, and what materials did you use for the car?
Kelvin.com has a 250 piece pack. That’s what we used for the track as well as for the car. (http://www.kelvin.com/Merchant2/merchant.mv?Screen=PROD&Product_Code=640090) There is more info about the car (2013) in a later post: https://marcoscorner.walther-family.org/2013/03/science-olympiad-div-c-maglev/. But that might only partially help for 2014.