2
\$\begingroup\$

I was making a voltage tester with the Uno and the input was A0. When I went above 10 volts into A0, that pin stopped working. Is it possible to fix the pin? If so, what do I do?

\$\endgroup\$
  • 4
    \$\begingroup\$ No. It's dead. Time to move on to the next pin and see how long that one lasts... \$\endgroup\$ – brhans Oct 1 at 3:05
  • 1
    \$\begingroup\$ Bag it and tag it and get another Uno. Write "NG" on the tag. "NG" is understood all the world around to mean "No Good." \$\endgroup\$ – mkeith Oct 1 at 3:11
  • 1
    \$\begingroup\$ @mkeith except at Arduino, where the "Arduino NG" was actually a product. But I digress... You are correct, that input is clearly gone, the rest of the chip should be looked on with extreme suspicion and used only as a last resort in unimportant temporary experiments. Replacing the MCU on the board would be a good experience. \$\endgroup\$ – Chris Stratton Oct 1 at 3:22
  • 1
    \$\begingroup\$ I would cut the pin off the module. It would be pretty clear to your future self that you knew it didn't work and made it obvious regardless of nomenclature. If you're brave enough to continue using it that is. \$\endgroup\$ – DKNguyen Oct 1 at 3:23
  • 2
    \$\begingroup\$ Is there an Arduino “NFG”? Because that’s what we usually mark such devices. Or “FUBAR” if there is room. \$\endgroup\$ – Spehro Pefhany Oct 1 at 6:24
4
\$\begingroup\$

You've definitely killed A0.

You may have killed other pins too so I'd avoid using that device again because you may end up chasing phantom problems which are going to slow you down.

| improve this answer | |
\$\endgroup\$
3
\$\begingroup\$

Your A0 pin is killed. Every I/O pin on a microcontroller is protected with a diode clamp, if the voltage on the IO pin goes above or below the supply voltage or very small time then it is clamped. But if it stays there for a longer time the clamp diode burns internally.

So, for using IO as input always use around 1KΩ series resistor and an external Zener clamp to avoid damaging of Microcontrollers Pin. as shown here!

| improve this answer | |
\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.