How to use Gyro on AI 2/AI 3?

[nolani12]

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.

[Thad House]

Originally Posted by nolani12

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.

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.