I hope this paper provides a good overview of the STM32F103 ARM microcontroller and embedded systems work! Let me know if you have any questions or need further clarification.
"Blue Pill" is a low-cost entry point for students and hobbyists. Core Learning Pillars the stm32f103 arm microcontroller and embedded systems work
Includes up to 80 fast I/O ports, two 12-bit ADCs, and various timers including PWM for motor control. How Embedded Systems Work with STM32F103 I hope this paper provides a good overview