We have updated our site with a short article with source code for a Arduino Mega 2560 - Midi Merging Analog Controller
The article is a about a quick mock up of a controller with MIDI IN, MIDI OUT and 3 analog controllers that send MIDI Controller Messages, on the MIDI Channel it receives from the MIDI IN.
The system could be adapted to not use MIDI OUT, and only send via the USB.
We are doing this as a first step in making a controller for VST instruments in our music production environment. We will be expanding this with more and other controllers.
It could be possible this will also work with the AlternateSerial that produces an extra serial port in software for the UNO version.
This is a short demo video of the mock up
We can be contacted at Art & Technology.