The Blue Pill PCB provides one GPIO-controlled LED to communicate by. Needless to say, this would be limiting if it were all you had. Perhaps the best early-development peripheral to pursue for communication is the USART (Universal Synchronous/Asynchronous Receiver/Transmitter).
This chapter will examine how to coax a STM32 USART to speak to your desktop through a USB serial adapter cable. A second project will demonstrate the same USART using two FreeRTOS tasks and a message queue.
USART/UART Peripheral
Within this book and technical literature at large, you will see the terms USART and UART used almost interchangeably. ...
