Yaw Rate Sensor
 

Looking at the Kit of parts, I do not see a yaw rate sensor this year. Is this correct?

Re: Yaw Rate Sensor
 

you can buy yaw rate sensors from one of the electrical suppliers though - they are not too expensive.

Re: Yaw Rate Sensor
 

Why are things so expensive on newarkinone.com? The Angular rate sensors sold on that site all exceed 150 dollars. I even saw some pushbutton switches for 20 dollars each.
Maybe I'm mistaken about the price, but that is ridiculous.

Re: Yaw Rate Sensor
 

the manual was slightly decieving. It gave the wiring for a yaw rate sensor, but it wasn't on the parts list. Here's to FIRST recycling its manuals!

-Kesich

Re: Yaw Rate Sensor
 

Newark is expensive, but they have everything. Just the nature of the beast, I suppose.

To compare prices between different distributors, try http://www.findchips.com/. It is an EE's bestfriend.

Re: Yaw Rate Sensor
 

Future electronics sells an Analog Devices angular rate chip. Search the fori for ADXRS300 & ADXRS150.

Others have used these with good success.

Joe J.


P.S.
My mind had them at $30 or so, but looking on the Future website they are more like $50 (and that is in a "tray" where you may have to buy 20 - ouch!). The ones pre-mounted on a PCB are almost $100. Pretty tough to use them at that price!

I KNOW Newark has them in my catalog, but I can't find them on their website (man their part number search could use some cleverness built into it -- dumb as a post, it is). If I find it in a old catalog and they sell it to me at that listed price, do you suppose I could still use it legally? -- I suppose not. Why does FIRST even HAVE that $200 electronic limit? Why not have a limit on what you can spend on bushings? It makes about as much sense.

Looks like Digi-key has the chips too. $50 is the going rate for the sensor in a surface mount package. I hope I can afford one or two.

Re: Yaw Rate Sensor
 

It makes sense, because they do not want you to have a complex component that will give you a terrible advantage. Why not buy another IFI controller? You could double your PWM outputs and inputs.

A $300 bushing is not going to give you a ridiculous advantage, or at least in the scope that a $300 electronic component might.

Plus, there is a limit on bushings--- $3500.

Re: Yaw Rate Sensor
 

I don't want to get into a philosophical debate about the custom circuit spending limit, but it wouldn't technically be legal to do what you suggest. The rules state that a custom circuit may not directly generate the PWM signals for the motor controllers.

Re: Yaw Rate Sensor
 

I bet there are lots of teams that have one from last year and never used it. Maybe you can make a deal.

Re: Yaw Rate Sensor
 

Go to the manufactures web site and see if they will send you an engineering sample for free. A lot of companys have this service. This may keep your spare parts cost down.



Tim Tedrow

Donatations don't make 'em legal!
 

The cost accounting rules in the kit require that you account for the catalog value of the parts even if you had them donated.

Note the references to "currently available" & "total catalogue value." How you actually obtained something is immaterial.

The way I read the rules, they have to be in the current catalogs and you have to meet the cost accounting limits with the listed prices.

Joe J.

Re: Donatations don't make 'em legal!
 

Can we use the gyro from our previous year robot? It's just sitting on there looking pretty after all.

Re: Yaw Rate Sensor
 

:confused:

the ones u wrote about r just chips. how do u plan to put them up on the robot??
if u have any info plz post it.

Re: Yaw Rate Sensor
 

FIRST nicely provided us with a big chunk of protoboard. The chips to which Dr. Johnson referred come in either BGA (ball grid array, terrible for us) or DIP (dual inline pin, very good for us) packages. I assume he plans to put them in some sort of enclosure and attach them to the robot using any of a number of available methods (nuts and bolts, epoxy, zip ties, it doesn't really matter).

Re: Donatations don't make 'em legal!
 

Yes, you should be able to, as the gyro's output is just an analog voltage between 0 and 5v.

Re: Donatations don't make 'em legal!
 

While you can easily hook them up to your CPU, as I read the rules they are illegal.

Joe J.

Re: Yaw Rate Sensor
 

i searched again.........
i didnt find any chips in DIP...........
could u please tell me where i could find the chips in DIP all i found was BGA :(

it would be really helpful if u could tell me where i could get one in DIP

thanks ^_^

Re: Yaw Rate Sensor
 

http://www1.future-active.com/Comerg...a me=ADXRS300
http://www1.future-active.com/Comerg...a me=ADXRS150

As far as I know, the ADXRS[150/300]EB are DIPs. Hmm, they aren't cheap... :(

Re: Yaw Rate Sensor
 

i cheked them out!

they arnt DIP
http://www.analog.com/Analog_Root/pr...S300%2C00.html

at the end bottom of the page it says that its grid array :(

i really don know how to use grid array and dont have the time either. am in a fix:(

thanks for ur help. plz tell me as soon as u find any thing

Gyros
 

Does anyone have specs on last years gyro?
or know the maker/model of it?

Thanks!

Re: Donatations don't make 'em legal!
 

My reading of the rules agrees with yours, Dr. Joe. But FIRST, today, said they ARE allowed:

Re: Donatations don't make 'em legal!
 

Yes, this seemed to me to be an odd answer to that question.
Is that part still available?
Is is available from one of the preferred suppliers?
Does it cost < $100?

If any of the above questions are answered "no" (and it looks to me like they are all "no"), then where does FIRST's answer to that question leave rookie teams?

Over the weekend I tried to submit clear questions that should resolve some of the discussions we've been seeing about what parts have to be in the $100/$200 limit, and in what cases the preferred suppliers have to offer the part. No response to those yet though.

Bill

Re: Yaw Rate Sensor
 

The -EB model is their Evaluation Board model, they have the same BGA chip premounted on a 20 pin dip board to make it easier to use.
Since technically, all it is is a pcb (which don't count towards price limits) and 7.2cents worth of caps, would we be able to use the price for the BGA?

Re: Yaw Rate Sensor
 

FIRST says we can use last years yaw rate sensor

______________________
Yes, this seemed to me to be an odd answer to that question.
Is that part still available?
Is is available from one of the preferred suppliers?
______________________

from team update 3, it sounds like they are saying, if you can get a part from one of the catalogs, then you can use a similar part, even if you actually obtain it from somewhere else.

I take this to mean, you can get yaw rate sensors from the catalogs, and the one FIRST gave us last year is "similar enough" that they will allow us to use it.

but you still have to account for its cost as an electrical component.