Troubles with FTDI on a custom Arduino

I am having trouble getting an external FTDI like usb2serial light working with this custom Arduino project:

As you can see, I included a capacitor of .1uF / 100nF 50V. What do I miss that is in the original Arduino's?
Of course I can and do use my ISP programmer, but especially for my students the FTDI board is more convenient.

Why do you have the FTDI connector pin CTS wired to the AREF pin of the micro? Not sure that is causing your problem symptom but it surely is wrong?


It should definitely have been wired to ground indeed! Must have been a momentarily blackout I'm afraid, or inherited from an earlier bad moment :slight_smile: