Deng Dazhong's RTL-SDR Expansion Board Brings Software-Defined Radio to Clockwork Pi's uConsole

Software engineer and hobbyist hardware developer Deng Dazhong is bringing a little connectivity to Clockwork Pi's compact uConsole handheld — with an expansion board that adds software-defined radio (SDR) reception to the gadget.

"I posted a few weeks ago about the RTL-SDR extension board project, but that board didn't go well. The RTL-SDR part didn't work at all," Dazhong admits of the project's inauspicious start. "The schematic of the RTL-SDR was based on my reverse engineering work on the RTL-SDR Blog V4 dongle. I still need to figure out the problem, but I did make a working RTL-SDR dongle based on the regular schematic with the R820T2 tuner. So, I use it for the RTL-SDR extension board, and this time, although the PCB still has some mistakes, after some fly wires, it works well."

The expansion board is designed for Clockwork Pi's uConsole, its compact handheld successor to the still-pretty-small DevTerm. Created using a modular design philosophy, the uConsole houses a system-on-module — either a Raspberry Pi Compute Module or one of Clockwork Pi's in-house SOMs — on a carrier board with the option of an expansion board to one side. Thus far, the only official expansion board is a cellular modem — but Dazhong's board uses the same connector for a software-defined radio instead.

"I designed an extension board with an RTL-SDR circuit, USB hub, and RTC [Real-Time Clock]," Dazhong explains of the design, which he is already working to expand with additional connectivity options — including a LoRa transceiver capable of transmission, on top of the receive-only RTL-SDR. "I will add GPS and LoRa to the RTL-SDR extension board. After that, I will start the production."

More information on the project is available in Dazhong's Reddit post; those interested in joining the waiting list for launch, or for consideration as a beta tester or reviewer, can fill in this form.