Yaw Rate Sensor

[gburlison]

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

[KenWittlief]

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

[bobtheblob]

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.

[Anthony Kesich]

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

[Adam Krajewski]

Originally Posted by bobtheblob

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.

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.

[Joe Johnson]

Originally Posted by bobtheblob

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.

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.

[Skabana159]

Originally Posted by Joe Johnson

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.

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.

[FotoPlasma]

Originally Posted by Skabana159

Why not buy another IFI controller? You could double your PWM outputs and inputs.

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.

[WizardOfAz]

Originally Posted by gburlison

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

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

[ttedrow]

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

[Joe Johnson]

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

<R61>

A FIRST robot may be built using only

• Items provided in the FIRST supplied Kit of Parts (or their exact replacement part)

•

Allowed Additional Parts and Materials as defined in this section in quantities consistent with the Cost Accounting requirements

<R71>

Additional electronic components for use on the robot must be currently available from Newark InOne (http://www.newarkinone.com), Future Active(http://www.future-active.com) or Digi-Key Corporation(http://www.digikey.com). The total catalogue value of dditional electronic components must not exceed $200.00 USD. This cost is counted as part of the $ 3,500 limit. No single electronic component shall have a catalog value of over $100.00 USD.

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.

[Matt Krass]

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

[rishi224]

Originally Posted by Joe Johnson

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.

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.

[FotoPlasma]

Originally Posted by rishi224

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.

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).

[Caleb Fulton]

Originally Posted by Matt Krass

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

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