So my local tractor pulling club uses one of those cheapo handheld surveyors' wheels for measuring the distance the sled has traveled. The competitions are all about distance, so this is vital to get right.
The surveyors' wheels have issues- the cases keep coming apart and they develop repeatability issues quite frequently. They also do not do speed at all, requiring them to screw with car GPS things when they need that. They're also junk, working by using brass brushes against a PCB, which I suspect is causing the repeatability issues.
'Professional' tractor pulling measuring systems cost like $2800. I think I can do better, even making it wireless, so it transmit distances back to the announcers' booth. Right now the sled operator tells the booth the distance by using a walkie-talkie.
I'm looking at using this rotary encoder with the original 13" measurement wheel:
https://www.sparkfun.com/products/10932I'd rather not use a cheap Chinese thing, but Rotary Encoders seem to be tough to find. Jameco doesn't seem to stock any and Digikey seems to only sell ones that look like pots or are like $500. Does anyone know of any other candidates?
I also need some sort of display for the Arduino that is easily readable in bright sun. The original uses a transflexive LCD like a wristwatch, so I'm thinking about getting one of those Nokia LCD displays. I'd like something a little larger, though.
Does anyone know if those OLED displays are readable in sunlight?