[oreocookeee]

first of all, let me say that i have no knowledge on the practical application of encoders. my team has never tried to use them (yet...). but i do have some knowledge in the backround of encoding technology, so here are some answers to your questions:

1+2) i would expect that mechanical encoders would be easier to use, but that depends on what your team is used to. i also agree that they would wear much faster than optical encoders so they would probably have to be replaced every once in a while. mechanical encoders also have some inherited flaws, like maxing out at a certain speed.

3) first, using the gear teeth as a cam for the encoder would provide much more "clicks per revolution" than you would need, and the speed may surpass the ability of the encoder. convoluted teeth are also an awkward curve to follow, putting a lot of stress on the teeth and the encoder. perhaps you could cut depressions in the side of the gear to make it a little easier to follow, and allowing you to adjust the click rate.

another thing you need to worry about is contact bounce. whenever a mechanical switch is connected to an integrated circuit, such as the FRC, the contact voltage can "bounce" from between high and low anywhere from a few to a few hundred times before reaching a contant state, all in an extremely short period of time. i dont know exactly how this would effect the FRC. maybe the FRC cycles too slowly to even detect the bounce.

7) binary is just plain base two numbering, where the digit weights correspond to values of 2^n. the binary number 101 is qual to (1*2^2)+(0*2^1)+(1*2^0).

grey code is a form of binary, but the actual correlation between the binary expression and the decimal expression does not follow the above scheme. grey code was designed so that only one bit changes for every integral increment or decrement. grey code was made specially for mechanical encoders because changing only one bit at a time minimizes digital errors. if two bits were to change in a single increment, then there is a chance that one bit may be detected before the other, causing the computer to think that the encoder jumped between three different states instead of two.

BCD is binary coded decimal. it functions the same way as regular binary, exept that each nybble (four bits) only goes up to the corresponding decimal value of 9. this way, one nybble can be used to easily express a decimal digit. for example, 7 corresponds to 1011, 5 corresponds to 1001, and 57 corresponds to 10011011

serial? mmm... cocoa puffs...

8) all of the above can be integrated with the FRC, but they may introduce complications for the programmers.

good luck with the encoders, and please let us know how it works out.