GYRO help

[srawls]

Hello All,
I'm working on a project for a summer internship that involves the gyro. Basically, I'll be making a robot that travels around a predetermined area, and makes an elevation map of it. I'll be using the gyro in the FIRST kit, and I'm trying to find the specification sheet. From the FIRST site I found the Yaw rate sensor came from a BEI System Doner, but a google search for BEI came up with a lot of foreign companies that don't sell gyros. So, if anyone knows the website for the company that provides the gyro I'd apreciate that a lot. I'm connecting it to a Basic Stamp, so I'm assuming I'll need an Anolog to Digital converter. If anyone has any expirience with that, what's a good one to use with the Basic Stamp?

Thanks,
Stephen

[Mike Gray]

The Maxim MAX187 is a 12-bit, single channel A-D that has a serial data bus and internal reference.

Try www.maxim-ic.com for other great peripheral chips.

Have fun with your project!

[ChrisH]

Stephen,

As I recall, you said in another post that your internship was with NASA. One of our engineers works at JPL and commented that they use the gyros all the time, BUT they filter the output, which we couldn't do until last year.

See if some of your co-workers have contacts over there. I'd give you his e-mail, but the journey "through channels" will be a valuable part of your internship experience. Remember, not all of the channels are official ones.

Chris

[srawls]

Thanks! I'll check to see if anyone here has contacts at jpl. BTW, I got the gyro just know, and there is documantation in the box, so I'm fine with that. By filter the output, do you mean in the code, or with electronics? (I'm assuming electronics since this was the first year we are allowed custom electronics). Anyway, I'm having fun here at NASA, and I'll keep you posted when I finish the project.

Stephen

[ChrisH]

Actually it might work either way. We tried to do a digital filter but the sample interval was too long for the response time we wanted. (We were trying to balance the bridge). For your application a digital filter might work just fine. It depends on how fast you're moving. For the electronic filter I think it was just finding the right value of capacitor. I seem to remember alot of time spent with an oscilliscope and wavy lines and flat ones.

But I'm just an ME and they don't let me mess with wires too much. Something about letting the magic smoke out too often.

ChrisH

PS let me know if you run out of channels, sometimes this sort of thing takes months which you probably don't have.

[Kevin Watson]

Stephen,

You can find a data sheet for the "GyroChip" here:

http://www.cvhsrobotics.org/resources.htm

For robotic applications, we use a Kalman filter to clean-up the raw output of our accelerometers and gyros. Using google, I found a pretty cool page devoted to Rudolph Kalman:

http://www.cs.unc.edu/~welch/kalman/

Have fun,
Kevin