serial to osc

Yup. I've come across the same problem when trying to connect TouchOSC to an Arduino ( well actually it was a Teensy3).
TouchOSC only receives and sends OSC messages and not OSC bundles.

Also, the library had a memory leak that had me scratch my head for a while but has been fixed in the meantime. You may want to download a fresh copy from The OSCuino GitHub site.