Hi, I have 4 buttons that connected to digital pin of arduino mega 2560, each pin is connected by using pulldown resistor with resistor 10k ohm and the source is 5v pin of the arduino..it was work before, bot now it doesnt work, i have checked the circuit but there is no problem there. after I use another pin it work again, what can cause the pins broke?
Thanks
Over-voltage perhaps?
Inadvertent contact with a higher voltage?
Long wires to the switches picking up strong interference from nearby power wiring?
Static electricity?
Or over current - setting the pins as OUTPUTs by mistake?
It is my opinion that connecting a switch to ground and using the internal pull up resistors is a better way of connecting a switch. See this Inputs
Did you set the pin as output, perhaps by loading the wrong program - and then push the button? That could result in a potentially damaging amount of current flowing.
Is the 5v supply not the same supply as the Arduino's 5v? If so, was it ever powered when the Arduino was not, and the button held down while it was in that state? That will back power it, which is a great way to blow pins.
Have you ruled out poor connections (ie, have you proved that the pin is bad, and it wasn't a wiring error incidentally fixed when you moved to a different pin)
@MarkT maybe,, is it possible 5v pin of arduino has higher voltage? because I use 12 V as source. i think the wire is not so long, and i'm sure i set the pin as output.
@Grumpy_Mike yesterday i try using internal pullup, and it work on pin that I think broken, maybe I will replace my circuit with this method..
@DrAzzy I already checked my connection and there is no problem, I use 5 volt pin of Arduino
patrixx:
Hi, I have 4 buttons that connected to digital pin of arduino mega 2560, each pin is connected by using pulldown resistor with resistor 10k ohm and the source is 5v pin of the arduino..it was work before, bot now it doesnt work, i have checked the circuit but there is no problem there. after I use another pin it work again, what can cause the pins broke?Thanks
Many relatively complex systems can break or fail at any time. Sometimes due to incorrect set-up or configuration, and sometimes due to a manufacturing fault or material flaw, or even a condition that the designer didn't bank on (unforeseen operating condition).
If it wasn't damaged due to the user, then it could be due to a failure that wasn't your own fault. But there's no certainty of it due to the lack of reliable operating history for this system.