While somewhat trickier to set up and use than a GPIO peripheral, the U(S)ART of ST’s STM32 families is fairly ... For our purposes (basic UART without DMA), pretty much anything goes, but ...

This day came when [Frans-Willem] was introduced to the STM32 series of chips with the ... LEDs all happens on an STM32F4 with the help of DMA and FSMC, or the Flexible Static Memory Controller ...