Arduino executing code, but not showing up on computer

Development Tools IDE 1.x
1

Hi there!

As the title suggests I do have a small problem with my Arduino Uno R3. I tried to power it with 12V on the Vin pin. Everything was running fine and even after connecting it to a regular 9V battery it was still working.
The only problem is that it is not recognized by my computer anymore. Everytime I plug it in the error "USB Device not recognized" shows up.

I don't know what I should do and any help would be appreciated.

2

Did you try the loopback test as described in a thread at the top if this forum?

3

I just tried to and I get stuck at connecting the serial monitor. When I click on ports in the Arduino IDE it doesn't show anything.