Features: 1. This product MMDVM is designed to be an open source multi-mode digital voice modem, which utilizes the functions of an ARM processor and a simple analog interface board. 2. The multi-mode digital voice modem is a combination of hardware and software development of the modem, which can handle all amateur digital voice modes. 3. Initially it will support D-Star and , later will support other versions, and built-in FM repeater controller. 4. The modem can be used in either simplex or duplex mode for all modes except and FM, while full duplex must be used for and FM. 5. This board needs to be used For PI3, , and various school development boards. Parameter 1. This board needs to be used with for PI3, , and various school development boards, running pi-star 2. This board has been used in GM300, GM3188, 3688, 950I, 338, -1X, other types of repeaters and bus stations need to be studied by themselves 3. For self-developed programming, Teensy 3.1/3.2 and mbed platforms, the only requirement for hardware is to be based on ARM M3, or M7, and have access to raw interrupts and ADC and ADC ports and digital signaling ports. 4.MMDVM open source multi-mode digital voice modem for Material: PC+Metal colour: green Package Contents: 1 x module 1 x connecting wire 2 x terminals Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.