Dan Michaels email (remove spam text)
Fred Bailey wrote:
>I have built a few interfaces from PIC's to ultrasonic sensors. Basically, you
>ping (trigger) the transducer using a FET and a good sized inductor (1uH). You
>have to wait for the ping ring to dampen down before you can see the echo
Were you using a Polaroid transducer, or the ceramic kind? I found the
following simple ckt on the robohacking sites. Any comments?
22K <--- probably too large
c U/S xmtr
PIC---1K-----b NPN |
>The echo amplifier is done with four or more op-amps in series to get about 10K
>gain in total. Many stages are used to keep the frequency bandwidth high.
Uh oh. Guess I would learn this soon as I breadboarded the ckt.
The ckts I've seen had fewer stages with more gain, but you are
certainly right. Hmmm.
>Try puting the sensor on a stepping motor and map in all directions.
Tom has stepper motors for everything :). My bot will probably
just turn its whole body [initially].
- dan michaels
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