vx8_gps | DIY GPS module for Yaesu VX-8DR/VX-8DE

vx8_gps is a C library typically used in Internet of Things (IoT), Arduino applications. vx8_gps has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can download it from GitHub.

When I was buying my Yaesu VX-8DE, I knew that I wasn't going to buy the original Yaesu FGPS2 module. There is very little APRS coverage in Israel and APRS in general seemed quite useless to me. The unreasonably high price of the original module didn't make me want to try it either. After receiving far APRS stations during a strong tropo over the Mediterranean I thought it would be nice to transmit some data. I started investigating how GPS transmits data and discovered the NMEA protocol I had never encountered before. My first source of information was the article Reverse Engineering the Yaesu VX-8DR GPS Interface by Taylor J Meek KG7BBG. I started from writing a Python program which was sending NMEA sentences to the transceiver. After some research I discovered the required message format and wrote a program which drew flowers on APRS map. Later, David Fannin's project inspired me to build my own GPS module. Thanks to his project I found out the ublox NEO-6M chip and a simple search on AliExpress showed that a ready module can be puchased for $10-20. I wrote my own software which isn't based on David Fannin's code. I started it as Arduino project but after finding out that the standard Arduino Serial library doesn't support interrupt driven writing and reading I decided to write it in pure C. After small changes the C code can be compiled in Arduino environment. The Arduino code is located in /arduino/vx8_gps_16mhz folder of this repository. I tried to document this project as much as possible and I hope it will be interesting and useful for other radio amateurs.