Subject:
|
Re: interfacing the GP2D12
|
Newsgroups:
|
lugnet.robotics.handyboard
|
Date:
|
Thu, 14 Oct 1999 20:48:00 GMT
|
Original-From:
|
"Matt Austin" <Falinn@ukmax.com>
|
Viewed:
|
914 times
|
| |
|
|
Thats great Gary,
This was the same conclusion that I'd come to myself, however I've
now run into another problem with the otherwise brilliant 'D12 sensor. I'm
currently using the Digitalker speech system from Jameco, and when the 'D12
is plugged in (I.e transmitting) it causes a lot of noise on the speaker,
and on any other speaker in the vicinity for that matter. Is there anything
to be done, shielding the 'D12 somehow? Any ideas? Thanks,
Matt
-----Original Message-----
From: Gary Livick <glivick@pacbell.net>
To: handyboard@media.mit.edu <handyboard@media.mit.edu>
Date: 14 October 1999 02:18
Subject: interfacing the GP2D12
> Somebody asked the other day about a problem interfacing the Sharp
> GP2D12. I didn't see an answer, and I just did it myself and solved the
> problem, so here is how to do it.
>
> For those who don't know, Sharp just came out with an IR ranging sensor
> good out to about 30 inches that provides an analog signal related to
> range. The signal is not linear, but that can be dealt with in
> software. The area examined by the sensor is very narrow, so by
> mounting it on a small servo and sweeping it while gathering range data,
> a lot if information can be obtained about the immediate surroundings.
>
> The GP2D12 has a few advantages over sonar; 1. it is good down to about
> 5", 2. it is less than $15.00, 3. it refreshes about every 32 ms, and
> 4. it does not require a driver, you just plug it in and start reading
> data.
>
> Hooking it up has one small gotcha with the HandyBoard and probably most
> of the other MIT-spawned boards as well. The output of the sensor wants
> to see a floating pin, but the analog inputs on the HandyBoard are
> pulled high by RP3, a 47k resistor pack. To connect the sensor to the
> HandyBoard, you have to cut a trace so the input can float on that pin.
> That is easy enough to do, as the traces on the main board are easy to
> identify, and easy to repair if you change your mind later and want to
> restore the pin to normal. However, some care must be taken to choose a
> pin for an input. If you just cut a trace for a pin at random, due to
> the way the circuit is layed out you may just isolate the input pin from
> the HC11 instead of removing the pull-up voltage. Unless you want to
> figure out what I'm talking about, use analog 5 to connect your GP2D12.
> Trimming the trace between RP3 and that pin has the anticipated result.
>
> The sensors are available at http://www.acroname.com Check out some of
> my robots in the gallery while you are there.
>
> Gary Livick
>
>
|
|
1 Message in This Thread:
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
