KBox serial outputs lock up when connected to a Raspberry Pi

[sarfata]

See discussion on mailing list:

I was able to reproduce the problem with a Raspberry Pi at home tonight and I have found a fix.

The problem is that the raspberry pi echoes back some USB packets back to KBox which other serial drivers do not do (apparently this is specific to raspberry pi). Because KBox was not reading the input, the serial port was getting stuck. Just reading and discarding incoming data fixes this.
For more details, you can read this message on the teensy forum: https://forum.pjrc.com/threads/23770-Teensy-3-0-goes-mute-when-sending-to-Raspberry-Pi?p=32304&viewfull=1#post32304

The solution is very simple, just add the following lines in the loop() function of your src/host/main.cpp file:

while (Serial.read() > 0 ) {}