You’ve found the GitHub repository for the outdoor unit / transmitter part of my wireless weather station, a.k.a. WX-TX.
A STM32 Nucleo-F429ZI ARM Cortex M4 development board running FreeRTOS serves as the heart of the outdoor unit. A BOSCH BMP280 sensor provides temperature, humidity and pressure measurements. A uBlox NEO-6M GPS receiver with a patch antenna provides time and location. An RFM69HCW ISM radio operating at 915 MHz transmits time, location and weather data periodically to the indoor unit / receiver for display and eventual upload to the cloud.
All code is written in C, with separate modules and tasks for each peripheral and a “core” task managing messaging between the peripherals.
More detailed information is available in the WX-TX Project Wiki