Tagged: motorola

GopherTrunk: A New Pure-Go Trunked Radio Scanner Supporting P25, DMR, TETRA, NXDN and More

Thank you to Matt Cheramie, who wrote in to let us know about his new software called GopherTrunk, a new RTL-SDR compatible radio scanner that follows digital trunked-radio voice calls and decodes them into audio. Gopher Trunk runs on a pool of RTL-SDR dongles and ships as a single ~10 MB static binary for Linux, macOS, and Windows. There are no C dependencies, so neither librtlsdr nor libusb are required at build or runtime, which makes deployment on a fresh machine or Raspberry Pi very straightforward.

On the protocol side, GopherTrunk handles control-channel decoding for P25 (Phase 1 and 2), DMR, TETRA, NXDN, Motorola Type II, EDACS, LTR, MPT 1327, dPMR, D-STAR, and YSF. The voice path is written in pure-Go and implements IMBE and AMBE+2 vocoders directly, removing the dependency on external DVSI or mbelib. The interface is terminal-based, but also includes a full browser-based operator console. There is also a configuration importer that parses RadioReference.com PDF exports and CSV bundles straight into the daemon config.

Matt notes that while the engine is running end-to-end, he is looking for SDR enthusiasts to test it against real-air captures to help refine the on-air FEC layers and vocoder audio levels. Prebuilt releases and the quick start guide are available at gophertrunk.org/downloads, and the full source is on GitHub. Feedback and bug reports are very welcome if you give it a try.

Gopher Trunk: A New Digital Trunking Scanner for RTL-SDR written in Pure-Go
GopherTrunk: A New Digital Trunking Scanner for RTL-SDR written in Pure-Go

Building an RTL-SDR “Moto Mod”

One nice feature of modern Motorola smartphones is that some models can accept ‘mods’, which are essentially phone cases that snap onto the back of the phone and interface via some exposed data pins. Some examples include a snap on speaker, projector, battery pack and zoom lens. Currently Moto Mods and Indiegogo are running a promotional campaign that gives developers a chance to pitch new Moto Mod ideas to Motorola, and if successful be partnered with Motorola and receive funding to complete and sell the hardware.

Vaclav Bouse is one developer who has been working on an RTL-SDR based Moto Mod. The idea is to integrate RTL-SDR hardware into the Moto Mod phone case form factor and possibly even add transceiver capabilities via an AX5043 transceiver chip. The hardware is still in the very early concept and design phases, and Vaclav is seeking donations on Indiegogo to help fund the development of a prototype (note that donating will not get you the final product). As it will be an RTL-SDR, it should be compatible with all Android RTL-SDR software, such as SDR Touch.

The hardware is also related to his other Moto Mod campaign idea which is a universal remote control.

The Moto Mod RTL-SDR Concept
The Moto Mod RTL-SDR Concept