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tkeenan
04-30-2006, 09:42 AM
I am wodering if you can you connect the Sharp GP2D12 IR sensor directly to a stamp to be used for·object detection?

Thanks for any ideas.

Tim

Chris Savage
04-30-2006, 11:38 AM
No really.· The GP2D12 outputs a non-linear analog voltage related to the distance of an object it detects.· You really should use an ADC0831 or similar to read it.

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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

Bruce Bates
04-30-2006, 12:14 PM
Tim -

Here is an interesting, and hopefully helpful article about linearizing the readings when converting from the Sharp GP2D12's analog voltage to distance:
http://www.acroname.com/robotics/info/articles/irlinear/irlinear.html

Regards,

Bruce Bates

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tkeenan
04-30-2006, 09:30 PM
OK thanks very much. I will look a different direction.

TIm

Jonathan
04-30-2006, 10:35 PM
T,

Here is a web page with some info on using the Sharp GP2D12:

http://madlabs.info/gp2d12/sharp_gp2d12.shtml

You *might* be able to use the RCTIME command, but resolution will be poor.

Jonathan

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www.madlabs.info (http://www.madlabs.info) - Home of the Hydrogen Fuel Cell Robot

Bruce Bates
04-30-2006, 11:07 PM
Tim -

The Sharp GP2D02 I/R distance sensor has a serial interface which easily interfaces with the PBASIC Stamp, and has all of the same characteristics as the GP2D12. Here are some applications notes:
http://www.acroname.com/robotics/info/examples/GP2D02-4/GP2D02-4.html

Regards,

Bruce Bates

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Larry
05-01-2006, 12:18 AM
You haven't said what your application is- so advice on which sensor to use is based on some conjecture on the advisor's part. Here are some things to consider.

GP2D15- simple (1 pin) digital interface. easiest to interface, rapid response, returns digital (on-off) reading when object is within factory predetermined range. Runs continuously, so it is a bit of a powerhog.

GP2D05- 2 pin interface. rapid response. returns digital (on/off) reading. Distance adjustable with dial on unit. Only runs when queried, so it uses less power. slightly slower response than GP2D15, since you need to query the unit each time.

GP2D02- 2 pin interface. Slow response(plan on 10 or fewer queries per second). serial interface, so it will give you range to object.

GP2D12- 1 pin interface. Runs continuously. intended to be used with an ADC. (recommend a cap to ground on the signal line to level out readings).·Response··time related to size of signal leveling cap. can be used with a voltage comparator·(alternatively a voltage bridge and Scmitt trigger buffer)to deternine a digital threshold that can be read with a Stamp.

There are also long range versions of most of these.

Hope that gets you started.



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