GQRX controller allows you to control GQRX with a physical interface. Actually you can control the frequency you are listening at and the type of demodulation.
Watch the video.
Actually, the Arduino uses the serial port to communicate with the computer. This data is collected by a processing programme which pipe the data in TCP/IP to GQRX.
Here some improvement to do :
- Replace potentiometer with a encoder to control the frequency.
- Add a potentiometer to control the squelch threshold
- Add a network interface to avoid the using of processing