This is the source code of ADF7021 version of the MMDVM firmware (MMDVM Hotspot), based on Jonathan G4KLX's MMDVM software. This firmware supports D-Star, DMR, System Fusion and P25 digital modes.
This software is intended to be run on STM32F103 microcontroller. You can build this code using Arduino IDE with STM32duino package, and using "make" with ARM GCC tools. Also, Arduino with 3.3 V I/O is supported, this firmware works on Arduino Due and Arduino Zero.
This software is licenced under the GPL v2 and is intended for amateur and educational use only. Use of this software for commercial purposes is strictly forbidden.