We updated the code and now it possible not only to save learned raw codes on the sd card, but also to read and send Pronto codes that are stored on the sd card.
The output of the display could also be sent over serial, but the whole idea is you can walk around with the doctor and improve your results as you go.
@Kokosnoot good solution. I remember the discussion in the early days of MySensors. I've powered the radio's for most of my sensors from the 3.3v regulator on the arduino board and for me that works perfect. But for my latest designs I decided to add a separate ams regulator for my radio's like the guys suggested in the beginning. Because you basically want the on board regulator to power the mcu only.
@DeepCore That is a need looking design. Did you consider using an alternative power supply other than usb? My Pi can't handle a lot of usb devices power wise, so I'm using a powered usb hub. But the wife doesn't like it, it's messy xd