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Author Topic: Now I really need help.  (Read 312 times)
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baum
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« on: January 15, 2011, 10:19:16 am »
 Bigger Bigger Smaller Smaller Reset Reset
None of my digital pins, except for pin 13, work. They all ouput ~4VDC and almost no current-- a 3mm green led plugged in to any of them stays off. (I wrote some simple code which pulls pins 2-13 high.)
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westfw
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« Reply #1 on: January 15, 2011, 11:12:08 am »
 Bigger Bigger Smaller Smaller Reset Reset
did you remember the pinMode(n, OUTPUT); statement in setup?  the behavior you describe is typical of leaving that out, in which case writing HIGH enables the internal pull-up resistor (about 30k[ch937]; very weak.)
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baum
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« Reply #2 on: January 15, 2011, 11:16:27 am »
 Bigger Bigger Smaller Smaller Reset Reset
Thanks!
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« Reply #3 on: January 15, 2011, 10:01:38 pm »
 Bigger Bigger Smaller Smaller Reset Reset
And you have a 330ohm or so current limit resister in series with your LED also so you don't damage the output?
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baum
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« Reply #4 on: January 15, 2011, 10:14:07 pm »
 Bigger Bigger Smaller Smaller Reset Reset
Yes.
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