Hello all, I have been doing a lot of reading up on Di2 and the e-tube app for iPad and iPhone. I'm pretty sure I have the proper battery, but do I need the bluetooth transmitter to connect my iPad to the Di2, or can I use the USB cable? I want to tinker with synchro shifting, plus I want to tinker with some other settings. I am new to Di2 so forgive the newbie questions. I downloaded the e-tube app, and it appears that I can only connect by Bluetooth. But I have read that I can connect with the USB. Thanks for any help, and I would also appreciate any good links you may have.