Reset/brown-out problem with BS2SX (was No subject)

Skarr

(forgot the subject line...)

Greetings!

I've had a BS2SX (in a BOE) for awhile and had to shelve it due to other diversions, but now I'm back playing with it once again. I wrote a simple program to get the cobwebs out of my brain that simply controls the motion of a little robotics platform. The drive wheels are two standard (Futaba) servo motors modified for continuous rotation. The program drives the platform forward, backward, left, and right. Simple.

The problem is that the program resets after some time and will not make it through the entire sequence of maneuvers. At first I thought it was a bug in the program, so I restructured it several different ways, and eventually I got the same result - a constant reset. Often times it wouldn't make it past the first maneuver.

I've tried using the wall wart and a newly recharged 9 V battery, but the result is still the reset. I've used different outlets in different locations throughout the room, thinking it might be a bad outlet, but to no avail.

I've checked on-board voltage regulator during its maneuvers and it reads around 5 V, which is what I would expect, so I don't believe it is a problem with the VR.

Any other ideas as to why I'm getting these resets/brown-outs?

Thanks in advance.

Regards,
Jeff

Bruce Bates

Jeff -

If you're powering the servos through the voltage regulator on the Stamp, a brown-out may be occurring, and the Stamp is being reset. Provide seperate power to the servos, and remember to keep the grounds of the two power sources common, and you'll probably be all set.

Regards,

Bruce Bates

Philip Gamblin

It still sounds like sagging voltage. A nine volt battery doesn't have a lot of capacity. I personally have never used one to drive servos. I suggest trying a AA 4 pack. I use the 15 minute rechargables (Rayovac) which have excellent longevity for small projects. If the program will run without the servos, it is most likely a brown out condition. Substitute LEDs fo rservos and see how it runs.

Chris Savage

·· One thing to be careful of with the rechargeable AA batteries is that they run at a lower voltage than standard AA batteries.· 4 of these is less than 5 volts!· You're already near the Stamp Module brownout point.· 4 standard AA batteries is 6 volts.· So if you use the rechargeable, you should use 5 instead of 4.

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Chris Savage
Parallax Tech Support
csavage@parallax.com

Skarr

Thanks for the tips, guys! I added a rechargeable 9V battery (7.2V fully charged) on a switch and that did the trick - no more resets/brown-outs.

Regards,
Jeff