Where can I buy Gyros that fit requirments?
 

Where can I buy gyros/yawrate sensors that fit with the requirments (price wise) and can interface w/ the robot computer w/o any custom circuitboards or anything? Can i use the Analog Devices ADXR150EB ? I'm not sure if it works with the robot controller and outputs the same stuff.... :confused:

Re: Where can I buy Gyros that fit requirments?
 

http://www.drrobot.com/products_wiro...p?categoryID=7 is a good source... the ADXR150 outputs a 40KHz samplerate 'analouge' value ( do a search on this there are hundrads of posts ) and can be read by the RC ana_in's

Re: Where can I buy Gyros that fit requirments?
 

you could use the Analog Devices ADXRS150EB which has a +/- 150° per second rate, or the Analog Devices ADXRS300EB which is +/- 300° per second

we are using the 150 on our bot - you connect +5 V and Gnd to a couple pins I think there are 2 +5V pins - and the signal that is produced if perfect for the analog inputs to the Robot controllers - roughly 0 to 5 volts

I got a pair from Avent electronics for $50 each - I dont know if future or digikey has them in stock - their prices were higher.

search on ADXRS150EB here on CD - you will find several threads discussing how to use them.

Re: Where can I buy Gyros that fit requirments?
 

I could not find any Gyros on the Dr. Robot page that you gave me....maybe i don't geet something.... can you give me the web address for avent electronics if i search i just get loads of garbage...
thank you
Salik Syed...
btw the gyros from 2003 or 2002 are definitely overpriced right?

Re: Where can I buy Gyros that fit requirments?
 

oh gosh- Ive been so brain dead lately!

I spelled it wrong in my post - its Avnet

sorry about that

edit: this is the electronics part page - but they show none in stock now
http://www.em.avnet.com/

you might try calling them - they may stock them as samples since they are evaluation boards

Re: Where can I buy Gyros that fit requirments?
 

Aha...........thanks.....do you know of anyother places where i can be able to get them? anyone ? Thank You

Re: Where can I buy Gyros that fit requirments?
 

if you cant find any from the distributors or catalogs, you might start a new thread specifically asking if anyone has a extra ADXRS150EB that they could spare?

I got two and would hate to give my only spare away, since its vital to the operation of our robot

but some teams might have purchased several and be willing to give up one.

but I would start a new thread to ask - not everyone reads everythread on CD all the way to the last post.

Re: Where can I buy Gyros that fit requirments?
 

Remember that even if you get the part from a different source, you must count the digikey/future active/newark price when doing your BOM.

edit: nevermind, see below

Re: Where can I buy Gyros that fit requirments?
 

That's what I thought as well, but the FIRST Q&A says differently:

Re: Where can I buy Gyros that fit requirments?
 

oops, I misread that message on Q/A. I had though it said the lower price from future active.

carry on.

Re: Where can I buy Gyros that fit requirments?
 

digikey lists them for $75 - so they are technically not over the $100 limit for a single item rule - thats the price I put on our BOM, even though we got em for $50

its like, if I give you one for free, you still have to put down its 'normal' value.

Re: Where can I buy Gyros that fit requirments?
 

Should I buy the one with the PC board (EB) or ABG which it just says is a GYRO

Re: Where can I buy Gyros that fit requirments?
 

Order the EB (evaluation board). It comes in a 20 pin mount that'll fit right into a regular printed circuit board.
The other is impossible to solder without very specialized equipment.

EB is the only way to go.
 

The ball grid array is a MAJOR pain to work with. It took a very skilled electrical tech in our building 4 hours to wire a single yaw sensor and another similar 2D accelerometer (ADXL202) with the circuit that comes build into the EB versions. The only reason we did it was to meet the $200 limit. Now that FIRST has made the limit $300 and has allowed us to use a $100 "EB" part while only accounting for a $50 "ball grid" part (see above), there is no way I would have had a team member spend that kind of time (the only benefit is that it "saves" $50 -- not worth 4 hours of a persons time).

Bottom line: Buy the EB version and run.

Joe J.

Re: EB is the only way to go.
 

This circuit board that it fits onto.......where do i get it......do i have to make the circuit board or something like that????... We don't really have that capability...i mean i was hoping 3 wires.. ground 5v and signal and i'd just put some crimps on :(

Re: Where can I buy Gyros that fit requirments?
 

the gyro chip itself is a tiny little thing, about a 1/4 inch square, and its a ball grid array device (BGA) - instead of pins it has a matrix of solder balls on the bottom that melt down onto a grid of pads when assembled onto a printed circuit board

thats why we advised everyone to get the EB version - its the gyro chip already mounted on a small printed circuit board, the size of a 20 pin DIP package if Im not mistaken, and it already has decoupling and filter caps on it

you could mount it on some of the protoboard they gave us in the KOP - the stuff you used to make the beacons - cut a piece big enough to put mounting screws through with the EB device in the center - attach the three wires (I think you have to connect power to two pins)

and you will be ready to fasten it to you bot.

We put ours in a black plastice 1x2x4" project box from radio shack, just to protect it.

BTW - you need to mount the board/box solidly to your robot frame - it cant be just hanging loose, or even on tape -you want a solid mechanical connection to the frame so the sensor moves exactly the same as the frame moves.

Re: EB is the only way to go.
 

Like Ken said, it isn't difficult.
You'll be attaching 5 wires total to the chip. Several of them combine, so you end up with three wires going to the RC.

pins 8 & 12 = Ground
pins 1 & 13 = +5v
pin 2 = signal