The M17 Working Group has a lofty goal for its open source communications project: "To kick the proprietary protocols off the airwaves" and give radio hams fully-open competitive alternatives.
"Ham radio is about experimentation and learning, but almost all radios used by Amateurs today are closed source and proprietary. The protocols themselves are usually more accessible, but require proprietary bits to actually implement, such as the voice encoding software," the Working Group explains of the M17 Project. "All current VHF+ digital radio protocols (D-STAR, DMR, Yaesu System Fusion, P25, ...) use some form of AMBE voice codec — which is patent encumbered and expensive to license, and certainly not available to the average ham. At the time these protocols were designed, AMBE was the only choice, but luckily, there is an excellent modern vocoder that is fully open — Codec2, by David Rowe."
"There's been a lot of work on making radios like this more accessible and more open, like all the work on OpenGD77, and MD380tools, but without open software from the OEM, this is a hard slog, constantly working just to stay in place. Even with fully open replacement firmware projects like OpenGD77, closed hardware means an incredible amount of work reverse engineering how the radio works. So let's build a radio protocol called M17, and a radio called the TR-9, that are fully open, and leverage all these lessons and projects we and others have built."
The TR-9 itself is a handheld radio built around the STMicro STM32F777VIT6 system-on-chip, with an Analog ADF7021 transceiver and an ESP8266 providing Wi-Fi connectivity. A 1.44in 128x128 TFT display offers an output for the user interface, while input is handled by an array of switches on the front of the two-layer "sandwich" board design.
The hardware's only half the project, however. The other half comes in developing the M17 protocol that runs atop the TR-9. M17 includes open source voice codecs and digital data protocols — with project founder Wojciech Kaczmarski declaring that "it's not just good enough to be open, it has to be legitimately competitive" against proprietary equivalents.