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Topic: Now I really need help. (Read 759 times) previous topic - next topic

baum

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.)

westfw

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.)

baum


CrossRoads

And you have a 330ohm or so current limit resister in series with your LED also so you don't damage the output?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

baum


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