You can, but that's irritating to do. In the case of the Pi there is no barrel connector, it's a USB port. So your only option is the header, either directly in

You can, but that's irritating to do. In the case of the Pi there is no barrel connector, it's a USB port. So your only option is the header, either directly into the holes if its unpopulated, or get a 40-way female header and solder to that, or go for a daughter board.