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Topic: Digital I/O Pins Output (Read 461 times) previous topic - next topic


Dear all,
i got this situation:

Atmega328p circuit is built and tested.. and it works fine.
BUT, i noted that all digital pins output only 3.7V instead of 5V,
while analog pins output 5V as normal !
i tried to remove extra parts to test and figure out the problem, but still the same
now i only got the Atmega, Oscillator and a pullup resistor to the reset pin, and i got no advantage ..
tried to redo the code, i even tried a very simple code:

void setup()
  pinMode(5, OUTPUT);
void loop() {
digitalWrite(5,HIGH); delay(5000); digitalWrite(5,LOW); delay(4000);

still got 3.7V on Digital pins
what could be the problem ?!


Pins here go between ~0v and ~4.9v

You may have damaged you pins in the past.

Show us a good schematic of your circuit.
Show us a good image of your wiring. 
Give links to components.
Posting images: 

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Jul 16, 2019, 10:08 am Last Edit: Jul 16, 2019, 10:09 am by BJHenry
Cant see the image here.
You aren't missing too much...


You aren't missing too much...

So, i guess this shall work just fine


So, i guess this shall work just fine
Does it work just fine? That picture is too blurry to be of any use.


I think you don't have the digital Vcc connected to power supply - bad soldering? It would well explain such behavior.
How to insert images: https://forum.arduino.cc/index.php?topic=519037.0

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