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Topic: LED stays on with ATmega chip removed (Read 1 time) previous topic - next topic

markdil

Maybe I am missing something.  I have a Arduino UNO board.  I remove the ATmega chip and the LED (pin 13) stays on.  According to the schematic, it should not.  What am I missing?  Thanks!

Mark

johnwasser

See the LMV358IDGKR (Op Amp) that drives the LED (to reduce load on the pin)?  Since removing the chip leaves that input floating it is possibly floating high and causing the LED to light.
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markdil

Thanks John.

Here is a link to the schematic I am looking at.  I see no OpAmp driving the LED.  Could someone point me in the direction of where I can get the current schematic?

http://arduino.cc/en/uploads/Main/arduino-uno-schematic.pdf

CrossRoads

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.

markdil


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