Software GPS receiver for STM32F4
See article (in Russian): https://habr.com/ru/articles/789382/
You can find same project for ESP32 here: https://github.com/iliasam/ESP32_SDR_GPS
This is a demo project of STM32-based SDR GPS receiver.
No additional factory/commercial "black box" GPS receiver is needed here - just connect MAX2769 (GNSS RF Frontend IC) to the STM32 MCU.
All "raw" GPS signal processing is done at the STM32.
Results of the GPS signal processing are send to the UART:
This is what the receiver looks like:
Video about this project:
https://youtu.be/1hBnaDsQgMc
Configured for STM32F4-DISCOVERY dev. board.
-Os optimization is used here
User must set PRN codes of 4 satellites in the code - before compiling FW (I'm too lazy to create real CLI).
User can set Doppler frequency offsets in the code to make acquisition much faster.
RF frontend pinout (See config.h):
#define SPI_CLK_PIN GPIO_Pin_13 //MAX2769 - CLKOUT
#define SPI_MOSI_PIN GPIO_Pin_15 //MAX2769 - I1
Both - GPIOB
Part of the code is taken from these projects:
https://github.com/tomojitakasu/RTKLIB
https://github.com/taroz/GNSS-SDRLIB