Generic embedded stuff used throughout hobby projects.
Comprised in here are drivers for processors, drivers for processor peripherals (e.g. SPI, UART, I2C), drivers for chips I come across (e.g. sensors, transmitters, etc).
Also contains kernel like stuff, e.g. task queue, preemptive scheduler, a.o.
Right now aimed mostly at STM32F1 and STM32F4.