Silicon Labs EFR32 transceivers give access to filtered IQ samples on receive, so it's possible to make a multimode handheld transceiver using them.
- Waterfall display (12 kHz wide)
- Receives FM, AM and USB
- Transmits FM
- Minimalistic user interface with a single knob
There are two major versions of the hardware. The first version is built around a BRD4151 radio module and only works in the 2.3-2.9 GHz band. See hardware_v1/ for details.
The second version is built on a custom PCB and uses a dual band EFR32 chip. See kapula/ for a KiCad schematic and PCB design.
The second version was designed for the 70 cm (432 MHz) and 13 cm (2.3 GHz) amateur radio bands. Apparently, EFR32 can be tuned over a much broader range:
- 13.2 - 725 MHz
- 766.7 - 966.6 MHz
- 1.15 - 1.45 GHz
- 2.3 - 2.9 GHz
The firmware is released under the MIT license. It depends on the Gecko SDK from Silicon Labs, mostly licensed under the Zlib license.
I haven't decided on licensing of the hardware design yet.