I just got my Diavolino kit and I'm a total newbie. I've melted my share of wires and circuitry just messing around and I don't want to make (further) mistakes by not following the instructions. I've yet to start and I've come upon a question.

I intend on using the USB and the battery box for power ( BUT NOT AT THE SAME TIME ).

On page #22, of the diavolino_instrux.pdf "How to add the Battery Box" The pictures show a Diavolino with the Reg. Bypass ( "No Reg" ) jumper already in place. None of the instructions previous to that point show installing this jumper. As far as I can tell the jumper is for required for just the 5V DC adapter. For battery box power is this jumper needed?

And just out of curiosity, why would one jump 3.3v to vcc? I'm still very green and from what I can tell this is to provide power to microcontroller (or not), to do what?

Thanks in advance.

On page #22, of the diavolino_instrux.pdf "How to add the Battery Box" The pictures show a Diavolino with the Reg. Bypass ( "No Reg" ) jumper already in place. None of the instructions previous to that point show installing this jumper. As far as I can tell the jumper is for required for just the 5V DC adapter. For battery box power is this jumper needed?

I believe that the jumper is *not* required. However I can also assure you that adding it is *not* harmful.

And just out of curiosity, why would one jump 3.3v to vcc? I'm still very green and from what I can tell this is to provide power to microcontroller (or not), to do what?

The AVR can't actually run off of 3.3 V; the 3.3 V power is produced on brand-name Arduino boards, and is available to power accessories on shields and so forth. Our option is just there for hackers to have more choices available.

Very good. My free time has evaporated lately, so I can only look longingly at the kit parts until this weekend. SIGH. (but then making a parts run will be that much easier )

Instead of a jumper to enable USB power, I've been using a Schottky rectifier - 1N5817 (or 18 or 19) to avoid any chance of dueling power sources. Those are cheap and can be had on ebay with no minimum order.

On the battery side, it costs a little more, but I'm happiest with using an LDO regulator that is reverse polarity protected.

so if i added a 2 pin header , jumping the 3.3 and vcc..would give me 2 pins on the header to use for 5 volts

so if i added a 2 pin header , jumping the 3.3 and vcc..would give me 2 pins on the header to use for 5 volts

Yes.