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Devantech Sonar

Hi guys, I have a strange problem. I have a small rover type robot that is controlled by a OOPic-R microcontroller. The problem is that the Devantech SFR05 Sonar Detectors have suddenly stopped working. When ever I plug them in something in the controller board starts making a high pitched squeaking sound. At first when this happened, the LED on the back of the sonar device would flash bright, then go very dim, but not go out. But now nothing happens. I have been running the oopic on a 9 Volt 200 mA transformer which seems to work for the oopic, but I don't know about the sonar. I have verified that the I/O lines that I am using work. Also the board makes the squeaking sound even if the signal lines are not plugged in and just the ground and 5V lines are plugged in. What happened? and If this in normal then what sonar detectors would you suggest?

Thanks

-Kit

Reply to
kitmor
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I'd provide battery power (four AA's should do) for anything off-board from the OOPic. This would include servo motors or sensors.

Be sure to connect the grounds of all battery supplies.

-- Gordon

kitmor wrote:

Reply to
Gordon McComb

Is the SFR05 able to run on 6V? I can't find a datasheet.

Reply to
kitmor

Don't bother trying to do that. I don't see an onboard voltage regulator on that ranger.

Personallay, I tend to use an external 5 volt power supply for my offboard stuff on most projects and I keep an eye on the current ratings of the added components.

Your words seem to indicate that the ranger was working at one point and then stopped - but I'm not certain of this. Not enough info. I can't tell if you are attempting to add other devices to the oopic that over tax the oopic's voltage regulator.

You may find this link usefull:

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The oopic-r seems to have a good plan for supplies.

If it was working and then stopped there could be a number of reasons including component failure (After all - there wouldn't be a need repair facilities and warranties if components didn't fail), solder splashes, or even a tiny bit of cut wire that got stuck on the board. Note... your description of a squeal and gradual-to-total failure leads me to believe that you have a component failure - certainly a sad, but not uncommon situation for experimenters such as yourself. Male and female connectors can also be problems. I've also found that I've even broken ribbon cables or accidently burned through ribbon cables with a soldering iron.

Other things I would do is try to run the ranger off a computer instead of the oopic - just to isolate the problem. Verify your wiring!

Bart

Reply to
Bart

Gerry doesn't do "standard" datasheets, but this page does answer the question, in a strict sense:

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It says +5V supply, so the answer to 6V is no -- at least until someone has tried it and says otherwise.

-- Gordon

Reply to
Gordon McComb

Without a datasheet, the pedantic question would be "What about 5.01V, 5.1V,

5.2V...?"

Mitch

Reply to
Mitch Berkson

The supply is 5 volts. It should be regulated and filtered for the 40khz spikes. A 7805 should be no problem. Don't sweat that small stuff, but I think 5.2V is getting close to the limit.

Reply to
Bart

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