Adafruit moto shield and PING sensor - sensor stops working

by ncoronges on Sun Feb 10, 2013 9:26 am

I have assembled and soldered the adafruit motor shield from kit, and successfully got motors, servo and PING distance sensors working.. HOWEVER, once the motors run for about 10-20 seconds, the PING sensor appears to just power off.. The distance readings also stop showing accurate readings. It appears that running the motors causes the PING sensor to power off, because i can run tests without the motors running and the sensor works consistently and apparently indefinitely.

The solder job is over all pretty crappy but i dont see anything obvious. Before i start general clean up, wondering if the above behavior sounds indicative of something particular. thanks in advance for any help.
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Re: Adafruit moto shield and PING sensor - sensor stops working

by adafruit_support_bill on Sun Feb 10, 2013 10:26 am

DC motors (and in particular the ones from that 4WD chassis in the photo) generate a LOT of brush noise that feeds back into the system. Sometimes it is bad enough to cause the Arduino to reset. In your case it sounds like it may be interfering with your ping sensor.

Look down near the end of the FAQ for a solution: http://learn.adafruit.com/adafruit-motor-shield/faq
Your kit may have come with 1 capacitor per motor, but based on the feedback we have been getting, most need the full 3 capacitor treatment.
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Re: Adafruit moto shield and PING sensor - sensor stops working

by ncoronges on Sun Feb 17, 2013 5:34 pm

Just wanted to mention i put 2 additional capacitors on each motor, for a total of 3 on each.. and this worked perfectly. no more signal failure on the PING sensor. thanks.
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