SBITX: Hackable HF SDR For The Raspberry Pi
Cheap, easy-to-use SDR switches are an extremely powerful tool for learning radio technology. However, building your own SDR is not something that many hackers are convinced they have to deal with. [Ashhar Farhan, VU2ESE] hopes to change that with sBITX, a hacker HF SDR transceiver designed around the Raspberry Pi.
[Ashhar] presented the project in a conversation at the virtual annual conference “Four Days in May” of QRP Amateur Radio Club International. Watch the full conversation in the video after the break. He first reviews the available open source SDR radios and then delves into his design solutions for sBITX. One of the main goals of the project was to reduce the barrier to entry. To do this, he chose the Raspberry Pi as the base and wrote C code that anyone who has done a little Arduino programming should be able to understand and modify. The hardware is designed to be as simple as possible. On the receiving side, a simple superheterodyne architecture is used to feed a 25 kHz wide range of RF spectrum to an audio codec that sends digital audio to the Raspberry Pi. The signal is then demodulated in software using FFT. For transmission, the signal is generated in software and then converted to the desired radio frequency. [Ashhar] also created a graphical interface for a 7-inch Raspberry Pi screen.