Amateur radio aprs module based on nanopi neo air

Most of the APRs hardware on the market are not open source and not user-friendly. I just want to make one directly.
After seeing direwolf using a sound card to build a complete set of aprs hardware, I felt that it should be a better solution. But in fact most people still use computers to do this.
So I wondered if this could be accomplished through embedded Linux, and so I came up with this project.
 
The BG5ESN on aprs.cn is 
 
implemented using the igate/DIGI built by it. Simply put, the hardware is an Allwinner core board (NANO PI NEO AIR) + CM108 (sound card).
 
The project is produced using Allwinner's H3 (NANO PI NEO AIR). The actual system only needs to run dietpi. The software source directly supports direwolf and can be installed through apt-get. The degree of freedom is extremely high. The sound card requires no driver and is directly recognized.
 
Here is some introduction:
1. The hardware design can be powered by 12V power supply or directly powered by 5V power supply, using the standard USB-C port.
2. The USB-C port provides power and also has a serial port function, which is convenient for Linux system debugging. Because the nanopi neo air is connected directly through wifi, there is no network port left.
3. In general, the output is AUDIO OUT, MIC IN, PTT, GND
4. PTT supports multiple methods, but I only tested the level method for triggering here. It has been connected to my free pass AT778UV, and then the PTT method can Change by jumping hat. .
5. A network port butt welding cable is designed to allow users to weld and change the connection method according to their own table. It also provides a 3.5mm headphone output port.
6. A GPS module was added and connected to NANO PI NEO, but there was no time to debug it.
7. The SPI and I2C interfaces are completely introduced, and a 3.3V channel is provided for them independently to facilitate later access to the screen.
 
BOM and materials can be purchased at Lichuang Mall.
 
A few errata:
the sound card power supply must be 5V, otherwise it may be unstable.