Got Gyro?

[PhilBot]

I was planning on using a gyro again this year, but I just noticed that there wasn't one included in the 2007 KOP.

Then I saw the rule about not using special FIRST custom circuits from prior years.

Is there an "approved" gyro board available this year?
Anyone have a part number?

If not, is it permitted to use the one from last year?
(I don't know if it was custom or COTS)

Thanks
Phil

[jgannon]

Your primary contact should have gotten an e-mail that tells you how to request the gyro and accelerometer at no extra cost.

[Conor Ryan]

Originally Posted by jgannon

Your primary contact should have gotten an e-mail that tells you how to request the gyro and accelerometer at no extra cost.

Here is a link to the original email that stated how to order the Gyros and Accelerometers

[Mike Copioli]

Originally Posted by PhilBot

Is there an "approved" gyro board available this year?
Anyone have a part number?

Here you go:

http://www.sparkfun.com/commerce/pro...roducts_id=395

This is the Gyro we use.

It's pricey but it works great.

[PhilBot]

Thanks everyone. The email will go out tomorrow....

So much to read, so little time

Phil

[kaszeta]

Originally Posted by Mike Copioli

Here you go:

http://www.sparkfun.com/commerce/pro...roducts_id=395

This is the Gyro we use.

It's pricey but it works great.

I'll second this. The turn rate of the kit gyro is too easy to hit. We used the ADXRS300 last year as well, although we wired up the eval board. The SparkFun one looks a bit easier to wire up.

We're using a gyro this year as well, it was really nice when the students rigged up a PID loop to keep the robot driving perfectly straight.

[michael714]

Hey Folks,
I submitted a request for the gyro and the accelerometer on 1/6 and still haven't received anything. Has anyone received theirs?

[Mike Copioli]

Originally Posted by michael714

Hey Folks,
I submitted a request for the gyro and the accelerometer on 1/6 and still haven't received anything. Has anyone received theirs?

No. We have not recieved ours either.

[kaszeta]

Originally Posted by michael714

Hey Folks,
I submitted a request for the gyro and the accelerometer on 1/6 and still haven't received anything. Has anyone received theirs?

Team 95 received ours late last week.

[EricS-Team180]

Originally Posted by Mike Copioli

Here you go:

http://www.sparkfun.com/commerce/pro...roducts_id=395

This is the Gyro we use.

It's pricey but it works great.

Thanks Mike and kaszeta, I usually buy the adxrs300eb right from analog devices, but they are out of stock 'till 6/07 and digikey is out until 4/07. =/ SparkFun didn't even come up on a google search. I was looking at piezo sensor yaw rate controllers for r/c helicopters, but we 'd have to hack one and I couldn't find the sensitivity (300deg/sec) we need anyway.
The SparkFun website says that their stock is down to under 20, so order one quick

Thanks
EricS

[Molly Stieber]

We haven't received ours yet either, and i ordered it the week after the kickoff.

[kaszeta]

Originally Posted by EricS-Team180

The SparkFun website says that their stock is down to under 20, so order one quick

I'm convinced that somewhere, the various inventory control guys at Digi-key, Newark, and Sparkfun all wonder why every January there is a run on ADXRS300 gyros, Grayhill 63R128 encoders, and the other various components many 'bots use that I can easily buy the rest of the year, but suddenly become out of stock during the build season.

[Danny Diaz]

Originally Posted by kaszeta

I'm convinced that somewhere, the various inventory control guys at Digi-key, Newark, and Sparkfun all wonder why every January there is a run on ADXRS300 gyros, Grayhill 63R128 encoders, and the other various components many 'bots use that I can easily buy the rest of the year, but suddenly become out of stock during the build season.

Hah, yeah, yet another reason we tend to purchase hard-to-find items during the off-season. We see FIRST like Christmas, do all your shopping for things you know you need or that you're low in stock of in order to beat the Christmas rush.

Ho Ho Ho.
-Danny

[jdejoannis]

Originally Posted by kaszeta

We're using a gyro this year as well, it was really nice when the students rigged up a PID loop to keep the robot driving perfectly straight.

That sounds interesting. I wouldn't mind learning more about this technique.

/Jason

[kaszeta]

Originally Posted by jdejoannis

That sounds interesting. I wouldn't mind learning more about this technique.

Our robot is basically a tank drive (left side and right side wheels centered on the robot), driven by a single joystick:

1. p1_y determines the speed of the robot. Set both L and R motors to this speed.
2. p1_x adjusts the desired heading of the robot.
3. Every time through the loop, you look at your current heading, and the
desired heading, and use the error between the two in a PID control loop
to set the amount you're adding to one side and subtracting from the other
to turn the robot to correct the heading.

This allows us to correct for motor biases and different traction between left and right and drive in a straight heading.

We've also used this same approach with a omnidirectional drive system, although we've never gone to competition with it.