Angolar Encoder

Hi, i'm trying to build a wind direction encoder, since it is my fisrt arduino project i have some questions:

1) i looked at the encoders i need an angolar encoder that allows endless cicle and i think this is the best one for my purpose, it's resistent, light and energy efficient

http://www.amtencoder.com/Product/AMT103

I'm just worried because since it is not absolute i'm afraid arduino could miss some A,B, value resulting in a wrong angular measurement, is this something i have to be afraid?

an alternative is this one but is more expensive, more complicated and it need serial communication for the absolute value (i think maybe it is too much for my needs).

http://www.amtencoder.com/Product/AMT203

Do you think it is better the first or second one for my project? and of course if you know a better solution post-it!

Thx

Gabriele

You can use interrupts for your encoder handler, which will allow it to capture all inputs, provided you have less than about 60,000 per second (unlikely, since even wheel-speed encoders don't go that high...)