PING))) alternative?

Philldapill

I was looking around on Futurlec.com today for some misc. parts I've been needing. I stumbled upon some pretty spiffy little ultrasonic sensors that looks strikingly similiar to the PING))) sensors Parallax sells. I'd love to buy the premade PING))) unit, but $25 is a little pricy... Instead, I'm wondering if these on Futurlec would work. Does anyone have any experience with these?

http://futurlec.com/Ultrasonic_Sensors.shtml
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Timmoore

I haven't used them but I believe these are the basic sensors, you will need the components to drive the tx and amplify the rx, which the ping has on board. Depending on the range you want, there are other options, Sharp have range detectors using IR. Take a look at
www.hvwtech.com they have some ir sensors and acroname.com they have both ir and ultrasonic sensors.
also the technical details on acroname.com on some of the ultrasonic sensors have schematics which might help you with using the futurlec sensors.

VIRAND

I have a PING which I haven't used yet for a specific application.
I do not remember the range of the PING but I DO remember an
ultrasonic experiment I did with a microcontroller driving a small piezo directly,
and receiving it's ultrasonic CW beeps by heterodyning with a small electret mic amplified by an op amp and LM386.
The range of that experiment was "between opposite corners of a warehouse" and included eerie echos
and doppler effects.

Therefore IMO, Small piezo + Small electret is probably a good alternative to those ultrasonic transducers.

Ken Peterson

VIRAND: Do you have more information about that configuration? How directional was it?

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KenLem

I can't tell if those are similar or not. Also, since there are no part numbers or data sheets, I wouldn't even know where to start to work with them.

So for $4, you could have a couple of sensors and spend who knows how many hours trying to figure out how to use them or, for $25, you can get the sensors on a board with documentation. Also, it's not just any documentation, it's Parallax documentation.

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Oldbitcollector (Jeff)

I think the PING unit is worth the money. I had a little trouble getting mine up and running at first,
but it was a software issue that was easily corrected. You are welcome to my code.

Most Radio Shacks have them in-stock, just don't forget the 1K resistor to play safely with the Prop.
(Better yet, all UPENE Expo attendees who are on my list will get one for free)

OBC

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Post Edited (Oldbitcollector) : 7/31/2008 4:18:27 PM GMT

Nick McClick

I've used the IR diode / receiver setup for a few projects. I've never used the PING sensor. What's the advantage? Better range? Easier interface?

The IR diode setup seems to work fine for me for some projects.

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jazzed

Nick, I found that IR reflection reiliability varies greatly with the color of the reflector ... white surfaces work best. Sonic reflections are not impacted by color but from other effects.

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grasshopper

Jameco sells these as well might want to take a look,

Philldapill

How is it that Jameco can sell these sensors FROM Parallax, yet buying them through the manufacturer, Parallax, they are more expensive...?

I just ordered one from parallax to reverse engineer it and see if the sensors I bought from futurlec will work as a drop in replacement. I'll update this thread when I get them in.

Anyone know what parts are need to build one of these PING sensors from scratch?

Mike Green

Parallax can charge less per item for large quantity orders. Jameco can decide how much profit to make. Perhaps they consider these "loss leaders" where they can sell them at cost or near cost in the hope of attracting customers for other items where they make more profit.

There's some kind of custom programmed microprocessor (SX28) and two other ICs. One I think is a driver for the transmitter. The other may be part of the receiver. You won't be able to get the pre-programmed microprocessor. You'll have to recreate it or its equivalent.

Timmoore

http://www.robot-electronics.co.uk/images/srf08schematic.gif
is a schematic of a similar ultrasonic sensor.

VIRAND

VIRAND said...
I have a PING which I haven't used yet for a specific application.
I do not remember the range of the PING but I DO remember an
ultrasonic experiment I did with a microcontroller driving a small piezo directly,
and receiving it's ultrasonic CW beeps by heterodyning with a small electret mic amplified by an op amp and LM386.
The range of that experiment was "between opposite corners of a warehouse" and included eerie echos
and doppler effects.

Therefore IMO, Small piezo + Small electret is probably a good alternative to those ultrasonic transducers.

Ken Peterson said...
VIRAND: Do you have more information about that configuration? How directional was it?

It was quite omnidirectional. I vaguely remember impressive range perhaps well over 30 feet.
(The transmitter and receiver were two totally separate devices, unlike a PING.)
I made it in 1992 and no longer have schematics but it would be easier to do nowadays I think.

jazzed

Anyone tried the MaxBotix stuff?

They're using a single transducer for both tx and rx.
Not sure if a Propeller based ADC would work with just the transducer or not.
The "buy now" link shows all their products on one page.
http://www.maxbotix.com/BUY_NOW.html

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