February 2015: See the status update at the homepage link below.
Here's a prototype of a cape that turns your BeagleBone Black into a web-controlled shortwave receiver. Several simultaneous web connections are possible each of which can independently tune a channel of the receiver. See the project homepage for details of the web interface.
The cape consists of an active antenna coupler, followed by an HF low-pass filter, +20 dB amplifier, 14-bit ADC and Xilinx LX25 FPGA connected to the Beagle over the SPI0 connection. For the software-defined GPS a Skyworks SE4150 GPS front-end chip connects to the FPGA. The GPS is used to accurately calibrate the receivers.
Since low cost is a primary goal this cape is not designed to be a general purpose FPGA development board. Existing capes (LOGi-Bone etc.) are already available. However, the FPGA is programmed from the Beagle and you can download any firmware you choose. The open-source software and firmware will allow experimentation with SDR and SD-GPS design.