I flashed both my U3S and QCX using an Arduino Uno. It turned out to be a lot easier than I expected. And the Uno can be called on to do a lot of other things! There's a pretty good document in the Files section on the process. You also need a few DuPont style jumpers which are easy to source, or make your own using one of the kits of DuPont connectors.
Cheers!
--Al
WD4AH
