STM32F401 Drivers Drivers build with the support of interrupts & some support DMA OS Scheduler Core Drivers NVIC SysTick MCAL Drivers RCC GPIO UART I2C SPI ADC DMA Flash CRC Timer (Counter) (PWM) (Input Capture) WatchDog Timer HAL Drivers LED Switch Character LCD Keypad HSerial HSPI Seven Segment EEPROM HI2C LED Matrix