I don’t know what is going on with my original Arduino Uno R2 board
I have downloaded the “blink” app which is toggeling PIN13 perfectly fine as long as it is connected via USB to my PC.
Once I have connected an external 12V power supply to the board, the green power supply LED is ON but the builtin LED on PIN 13 is not blinking anymore…
Am I missing something? Isn’t it possible to run a sketch on the board without the USB connection to the PC?
Thanks for your support