user14727: What are the most common ways of destroying a Arduino using the I/O pins?
Also, in what situation would it be acceptable to attach the positive or negative end of a power supply to an I/O pin?

user6424: There are many ways to destroy an Arduino, check out this article, 10 Ways to Destroy An Arduino.


Shorting I/O Pins to Ground
Shorting I/O Pins to Each Other
Apply Overvoltage to I/O Pins
Apply External Vin Power Backwards
Apply >5V to the 5V Connector Pin
Apply >3.3V to the 3.3V Connector Pin
Short Vin to GND
Apply 5V External Power with Vin Load
Apply >13V to the Reset Pin
Exceed Total Microcontroller Current



14727: <p>What are the most common ways of destroying a Arduino using the I/O pins?</p>

<p>Also, in what situation would it be acceptable to attach the positive or negative end of a power supply to an I/O pin?</p>
 6424: <p>There are many ways to destroy an Arduino, check out this article, <a href="http://www.rugged-circuits.com/10-ways-to-destroy-an-arduino/" rel="nofollow noreferrer">10 Ways to Destroy An Arduino</a>.</p>

<blockquote>
  <ol>
  <li>Shorting I/O Pins to Ground</li>
  <li>Shorting I/O Pins to Each Other</li>
  <li>Apply Overvoltage to I/O Pins</li>
  <li>Apply External Vin Power Backwards</li>
  <li>Apply >5V to the 5V Connector Pin</li>
  <li>Apply >3.3V to the 3.3V Connector Pin</li>
  <li>Short Vin to GND</li>
  <li>Apply 5V External Power with Vin Load</li>
  <li>Apply >13V to the Reset Pin</li>
  <li>Exceed Total Microcontroller Current</li>
  </ol>
</blockquote>
