One of the nice things about the STM32 MCU is the availability of the USB (Universal Serial Bus) peripheral. With USB, it is possible to communicate directly with a desktop platform in various modes. One of these flexible modes is USB’s emulation of a serial link between the MCU and the desktop.
This chapter will explore the use of libopencm3 and FreeRTOS working together to provide a convenient means of communication. You will use the USB CDC class of operation (USB communication device class). This provides a very convenient means for interacting with your Blue Pill.
Blue Pill USB Issue
First, let’s clear ...
