How to use Gyro on AI 2/AI 3?
 

I'm doing some gyro sensor testing on an old bot and wanted to hook more than two up at one time. (I have 5 sensors and have to pick out the two best ones.)

The Gyro test VI only lets you choose AI 0 and 1 for the gyro. I tweaked the VI quite a bit for my usage. I was thinking, why not just modify the enum (that only lets you use 0 and 1) to allow for more ports? So I dug down to lower level VI's like Gyro Open and it appears that does nothing to restrict what ports you can use. I went in the Gyro Test VI and went ahead and edited the enum to allow all 4 AI ports 0-3.

Ran the VI with 2 selected, nothing happens. 0 and 1 work fine, but 2 and 3 do not.

Is there a reason we cannot use the other AI ports? Are they reserved for something else? We normally have pressure sensors on the other AI's (and use only 2 gyros) but for testing it would be great to use all 4. And I'm just curious why it would not let you use them.

Re: How to use Gyro on AI 2/AI 3?
 

The gyroscopes use an accumulator built into the FPGA to do the integration of gyro rate to get the gyro angle. There are only 2 of these accumulators in the FPGA, and they are assigned to Analogs 1 and 2. You could manually write your own integration accumulator to use more gyroscopes, however they would probably be less accurate as a software accumulator would run at a slower rate then the FPGA accumulator.