Software GPS receiver for ESP32
See article (in Russian): https://habr.com/ru/articles/789382/
You can find same project for STM32 here: https://github.com/iliasam/STM32F4_SDR_GPS
This is a demo project of ESP32 based SDR GPS receiver.
No additional factory/commercial "black box" GPS receiver is needed here - just connect MAX2769 to the ESP32 MCU.
All "raw" GPS signal processing is done at the ESP32.
Results of the receiving are displayed at the LCD:
Video about this project:
https://youtu.be/1hBnaDsQgMc
Configured for ESP32-2432S024C board (SPI ILI9341 + CST820 capacitive touchscreen) - CYD variant.
-O2 optimization is used here
RTOS tick period - 1ms
LCD+Touch pinout is set by menuconfig
LVGL 8.3.0 is a managed component, must be downloaded by ESP-IDF
ESP-IDF 5.0 is used here
User must enter PRN codes of 4 satellites in GUI before start.
User can enter Doppler frequency offset to make acquisition much faster. "-" symbol is entered by holding "delete" GUI key.
Compiler output:
Total sizes:
Used static DRAM: 134404 bytes ( 46332 remain, 74.4% used)
.data size: 8372 bytes
.bss size: 126032 bytes
Used static IRAM: 58930 bytes ( 72142 remain, 45.0% used)
.text size: 57903 bytes
.vectors size: 1027 bytes
Used Flash size : 480075 bytes
.text : 393267 bytes
.rodata : 86552 bytes
Total image size: 547377 bytes (.bin may be padded larger)
RF frontend pinout (See config.h):
#define GPS_SPI_CLK_PIN 18 //MAX2769 - CLKOUT
#define GPS_SPI_MOSI_PIN 23 //MAX2769 - I1
#define GPS_SPI_CS_PIN 5 //To GND
Part of the code is taken from these projects:
https://github.com/tomojitakasu/RTKLIB
https://github.com/taroz/GNSS-SDRLIB
https://github.com/VitorAlho/lvgl_esp32_drivers