USB-Serial Converter Overheated - Faulty Code?

Hello,

during my first prject with the arduino I ran into an unexpected problem, the USB/Serial converter MEGA16U2 seems to have overheated.

I wrote a simple sketch, which sends a IR-Signal using a IR-LED on pin 13 at a specified time using Time.h and TimeAlarms.h. When I left it running overnight the first time, I removed the USB-Connection and powered the Arduino via a 12V power supply. When I woke up the Arduino was really hot and the USB/Serial converter looks like the plastic melted a bit.

The sketch sends a current time every second via serial, could that be the reason for this or was I just unlucky?

Thanks for any input!

Enrico

I don't think faulty code could overheat it. Most likely a fault in how you wired it to the LED or to the 12V power supply. You may want to have a look at the data sheet for the IR-LED and for the voltage regulator on the Arduino, and make sure you are using them properly. Some power supplies output higher voltage than they claim on the label. The best way to power an Arduino board is to use a USB cell phone charging block, such as one that comes with an iPhone, Android, or Blackberry phone, and connect it via a regular USB cable. If the LED calls for a series resistor, don't forget that.