[Josh Hambright]

What teams used wheel encoders this year?
461

How did you build it or did you buy a shaft encoder?
Digikey partnumber: CT3003-ND
These are 4 bit grey code binary rotary encoders. Very small and fairly beefy. I knew that i needed some kind of rotary encoder because i have been teaching lego robotics at the museum i work with and have been involved in lego league so i knew we needed some kind of enocoder and these were the ones we ended up with. They are 3.50 a piece so it kinda sucks when you break one but it wont break the bank to replace it.

What was its resolution?
4 Bit...its grey code which was fun to figure out.

Did you use them only for autonomous or for the whole match?
We used them for a few different things. During autonomous they were part of our system for positioning which was used in conjunction with the gyrochip. They also alowed us to do things like make sure the speed of the wheels were the same when we were trying to go straight in user control mode. And they were handy for debuging stuff because we could test the speed of our wheels.

How did they work for you?
Really well. The whitesheet for them wasn't great but once we got it figured out it worked great. They were small and dependable. They wore out after 10,000 cycles so we switched them out before nationals...well that and the fact they took a direct hit from another robot and the shafts got bent off... But they were easy to switch in and out due to a small shaft connected to the drive shaft that just had a set screw and mounting bracket next to it. We could just pop a new one in, if they got broken.

Do you plan to use it next year?
If there is autonomous again i am pretty sure we'll use them again. We are going to try and develope some custom circuittry so we dont have to waste 8 digital inputs just for rotary encoders. We have also looked into simpler solutions like using the optical sensors and a reflective something like wildstang and other teams used.