The Stm32f103 Arm Microcontroller And Embedded Systems Work May 2026
The STM32F103 is a popular 32-bit microcontroller family based on the ARM Cortex-M3 core, widely used in embedded systems due to its balance of performance, low cost, and rich peripheral set. It is frequently the subject of textbooks, such as The STM32F103 Arm Microcontroller and Embedded Systems
Priya grinned. “It wasn’t the ARM core. It wasn’t the peripherals. It was your NVIC priority grouping. You had the ADC interrupt preempting the USART transmit complete flag.” the stm32f103 arm microcontroller and embedded systems work
Interrupts: The microcontroller can generate interrupts in response to events, such as timer expiration or I/O completion. Interrupts can preempt the main loop and execute interrupt service routines (ISRs).
The trade-off? HAL adds overhead. A bare-metal pin toggle takes ~50 ns; a HAL toggle takes ~500 ns. For most applications, this is irrelevant. For tight loops, you mix HAL (for setup) with direct register writes (for speed). The STM32F103 is a popular 32-bit microcontroller family
To turn on an LED, you don't call a function like digitalWrite() (unless you use a library). You write a 32-bit value to a specific address. For example, to set PA5 high on GPIO Port A: Interrupts : The microcontroller can generate interrupts in
- Flash Wait States: At 72 MHz, the Flash memory can't keep up. The CPU inserts 1-2 wait states, slowing execution. To fix this, critical code is copied to SRAM (which runs at 72 MHz with zero wait states).
- 5V Inputs: The STM32F103 is 3.3V logic. It is 5V tolerant on most pins (meaning you can apply 5V safely via a series resistor), but it outputs only 3.3V. Driving a 5V relay requires a transistor or level shifter.
- Debugging: Without an OS, you can't
printf easily. Instead, you use Serial Wire Debug (SWD) with a ST-Link adapter. You set breakpoints in Keil, IAR, or PlatformIO. For cheap logging, you route printf to a USART and watch on a serial monitor.
