View Full Version : Stamp rebooting computer?

04-07-2007, 10:39 PM
Has anyone else had a problem with the stamp (BS2sx) some how making your computer restart every now and then?

Mike Green
04-07-2007, 11:23 PM
There should not be any way for this to happen from the Stamp side. The PC (if designed properly) should be pretty immune to anything you could do from the other side of a serial or USB cable other than plugging it (the serial or USB cable) deliberately into an AC socket or other source of high voltage. If there's something wrong with how you've installed the serial drivers for a USB adapter, that could cause a restart, but reinstalling the drivers should fix that. You might have a virus that interacts with the USB drivers (if you have USB).

Both USB and serial hardware ports are supposed to be pretty resistant to static discharge and other invalid signals.

04-08-2007, 11:21 AM

I played with this circuit for quite a while today, and it has not restarted my pc, so what ever that
was is hopefully gone.

The command interperter is getting warm, so I checked, and the stamp itself (between pin 21) is drawing
60 Ma. I removed the 2803, and it did not change, so I removed the 10K on the inputs, same thing
no change...

Attached is the circuit I'm using.

The program is right out of the manual for reading in a voltage, except I'm using a LM35 instead of
a pot, and outputing to an LED when it reaches a temp.. It works great! But the heat is a concern..

Does this look OK?

Mike Green
04-08-2007, 11:51 AM
As I mentioned, the BS2sx is one of the most power hungry of the Stamps and does indeed draw about 60ma when running (not in sleep mode). When driving the ULN2803 (output high), the Stamp's current consumption will go up slightly (maybe 1-2ma per high pin). The LEDs themselves will draw approximately 10ma each when on. The ADC0831 doesn't draw more than 1-3ma including the LM35.

If the Stamp is getting warm, but not hot, I wouldn't worry. You're dissipating about 1/3 watt in the Stamp and you should be able to feel that as a little warmth.

04-08-2007, 11:58 AM
Cool, thanks Mike!

I have the program only turn on one LED at a time, and turn it off for 1 sec before the next one
comes on (rising temp), so it should be good..