Looking for a good, cheap gyro
 

Hey, new to the forums so don't eat me :D

Just wondering where I could get a cheap, reliable gyro. It'll be used for keeping our 2011 robot on course and to more accurately move to its target(s).

I was looking online and found a bunch of breakout boards, but seeing as I'm the programmer and don't know if those are acceptable/usable on an FRC robot I'd like some help.

Any references and/or comments would be appreciated.

Re: Looking for a good, cheap gyro
 

Is there something inadequate with the one that came in the Kit of Parts?

Re: Looking for a good, cheap gyro
 

As previously stated the one supplied in the KOP should be fine.

If not, you can get this one. It should be adequate.
http://www.sparkfun.com/products/8372

Re: Looking for a good, cheap gyro
 

If you are near Houston... :p

Re: Looking for a good, cheap gyro
 

I have to say, that made my day.

Re: Looking for a good, cheap gyro
 

I have to say, my day has been made too. Although I would advise not mixing gyros with gyros (unless your local hobby shop has a good Greek snack bar, in which case, go for it!).

On a more serious note, I'll reiterate that the KOP Gyro should be sufficient for most uses. If not, others should be pretty easy to find. Heck, Amazon's got 'em. They seem to be readily available elsewhere too.

Re: Looking for a good, cheap gyro
 

Also not to be confused with a BMX gyro. It is a device used on BMX bikes to allow bar spins without wrapping the rear brake cable. See the attached image.

Re: Looking for a good, cheap gyro
 

We found the kit of parts gyro unreliable in the event of an earthquake ...

On a more serious note we had a few issues with the KOP gyro mainly drift and other wierdness, dunno if it was stock code or what but on occasion our robot felt like it was spinning at 5 rads a second.

If you are looking at non-frc gyro then what about one used in R/C helicopters?

Re: Looking for a good, cheap gyro
 

That kind of drift is not normal, either you gyro is defective or your code is (did you remember to calibrate it?). Our KOP gyro and stock code had less than 0.1deg/sec drift.

Re: Looking for a good, cheap gyro
 

Has anyone tried using a more sophisticated gyro with thermal compensation and filtering onboard, interfaced over the I2c port?

Re: Looking for a good, cheap gyro
 

Unless the gyro has built in integration, it would take a lot of I2C traffic to sample it at a high enough rate, and you'd have to write your own routine for integration.

Re: Looking for a good, cheap gyro
 

Check if both of your speed controllers have the jumpers in the right configuration. One year, we had that problem, I thought it was just the chains or something. But it turns out one speed controller was configured to "brake" and the other to "coast".

Re: Looking for a good, cheap gyro
 

I found these real quick although the second one is an SMD
http://www.robotshop.com/pololu-dual...t-board-2.html
http://www.sparkfun.com/products/9445
These were the cheapest I could find, but if you want to look at sensors these are the sites I usually use
http://www.robotshop.com/
http://www.sparkfun.com
http://www.makershed.com/
http://www.adafruit.com/

Hope that helps

Re: Looking for a good, cheap gyro
 

Integrating the gyro is very doable. We did it in 2010, I believe I still have the code (In Java) somewhere. However it was an analog sensor, I never got to work with an I2C one.

On the subject we also have a good experience with the KOP gyro.

Re: Looking for a good, cheap gyro
 

You have a mentor who works with me at SpaceX. Tell him what you need and I'll see if I can set you up.

-Kevin