CTS CT3003-ND 4 bit gray code encoders...
 

...I know people have already used these and I ask that the wiring diagram be posted. The spec sheet is not of much help. Judging by the volt meter, it is a simple switch, but the spec sheet for a similar encoder says that it is a digital switch with an internal pull up resistor? I sincerely appreciate any help trying to wire these beasts.

Re: CTS CT3003-ND 4 bit gray code encoders...
 

First off CTS CT3003-ND is a Digi-key item number, not the actual part number. I knew what you were talking about though, bc i'm just that nerdy and memorized the the entire digi-key catalog and all the part numbers. (actually they just all end in "-ND") :) 288T232R162A1 is the actual CTS part number.

Anyway, this particular part is nothign more than a mechanical switch that contains no circuitty. Most encoders are a bit higher end than this and their working are a bit more complex. I'm too lazy to explain that though unless your really curious about it. As far as wiring it goes, its pretty straight forward. I'm not sure exectly which pin is which but basically you have a common pin and a bunch of other pins. Connect the common pin to the "+5v" pin of one of the digital inputs. Connect each of the rest of the pins to "sig" pins. For details on the pattern it outputs see: http://rocky.digikey.com/WebLib/CTS/...8%20Series.pdf

The encoders you chose arn't really meant for this sort of use, but i guess they will work. They are actually meant for light duty human interface applications such as VCR controls and stuff liek that.

Re: CTS CT3003-ND 4 bit gray code encoders...
 

Alright... I have a correction for my above post. Instead of hooking the common pin to +5v, hook it to ground. This is because all of the inputs on the robot controller have pullup resistors. This means that whenever nothing is hooked up to them(or an open circuit is hooked up to them), a resistor "pulls" them to +5v. If you were to hook 5v to them, nothing woud happen. Instead, you have to hook them to ground to change the state of the imputs. Basically whenever you hook them to ground, ie:through a switch, the pullup is overpowered and they are brought to ground.

Re: CTS CT3003-ND 4 bit gray code encoders...
 

i hope your not trying to use these on a drive train! their avrage life is 15,000 revolutions. our robot has a 1/3 gear ratio to the wheels, and they turn at like 300 rpm. this sensor would wear out in a matter of minutes!

if your going for high presision stuff like, say, an arm, it is *okay* but there are better options. like limit switches? lol jk have fun with this. i just hope you dont use intrupts...

Re: CTS CT3003-ND 4 bit gray code encoders...
 

He is right. They will wer out under even moderate use. I mentioned this briefly before, but didn't really emphasize it much. If you are thinking about using these with anythign that will be doign alot of err... turning, i would suggest you get something else.

Re: CTS CT3003-ND 4 bit gray code encoders...
 

What does "gray code" mean and what is the difference between 2 bit and 4 bit gray code. Digikey has a 2 bit and 4 bit gray code encoder and they both have 3 terminals

Re: CTS CT3003-ND 4 bit gray code encoders...
 

Charlie,
Gray Code is just another kind of binary coding used to generate data from these devices. The three pin device you refer to is the two bit part. The higher resolution part has more pins. The data sheet Jim listed above covers all of the parts in this family and includes the output tables for two bit, gray code and hex encoded outputs. Note how they differ from simple binary coded outputs. It is a little hard to follow but the individual part numbers are listed in the part number finder at the very bottom of the article. If you have a method of decoding gray code (either in a micro of your own design or with code you loaded into the RC) you can get up to sixteen distinct positions per revolution with the four bit varities. Again, these are not meant to be continuous rotational devices. They work great for coarse position selectors or one of several selectors. (i.e. you choose which of 16 preset conditions you want to start with)