arnaud acquired a HackRF Blue and has been busy coding up a GNURadio project for analyzing Crazyflie radio transmissions. Crazyflie is a nano quadcopter/drone controlled over a wireless link. The Crazyradio is the official radio dongle for the Crazyflie Nano Quadcopter. It is a 2.4GHz USB radio dongle based on the nRF24LU1+ chip from Nordic Semiconductor.
arnaud uses GNU Radio companion to design a receiver for the Crazyradio’s GFSK signal, calulating the magnitude of the complex signal which allows to locate data packets by setting the scope trigger. Once able to synchronize on a packet, we can add a filter and a quadrature demodulator to demodulate the FM signal and show the data packet (in green).
For more information and explanation of the GRC file, check out the detailed post at Bitcraze.io.