Microcontrollers

What is a Microcontroller?

Microcontrollers are integrated circuits combining a processor core, memory, and input/output peripherals on a single chip. As the cornerstone of embedded systems, they come in various architectures like AVR, PIC, STM32, ARM Cortex-M, and ESP32. Choosing the right one depends on processing power, power consumption, available peripherals, and the development ecosystem.

Types and Selection Criteria

• Architecture: 8-bit (AVR, PIC) vs 32-bit (ARM Cortex-M, STM32, ESP32). For complex tasks such as GUI or TCP/IP stacks, a 32-bit chip is recommended; for battery-powered minimal projects, low-power 8-bit devices excel.
• Flash / RAM: Program and working memory sizes limit code complexity. If using graphical interfaces or communication stacks, aim for at least 64 KB Flash and 20 KB RAM.
• GPIO and Peripherals: UART, SPI, I2C, ADC, PWM outputs. Ensure enough pins and protocol support for your sensors and actuators.
• Package Type: DIP (breadboard-friendly), QFP, QFN. Prototyping ease vs mass production priorities determine this choice.
• Supply Voltage: 3.3V and 5V are common. Mismatching with other components without level shifters can lead to failure.

Common Mistakes

Insufficient memory selection, bootloader incompatibility, neglecting decoupling capacitors on power lines, leaving analog inputs floating, and incorrect oscillator configuration are frequent pitfalls. Additionally, connecting high-current actuators directly to low-current GPIO pins causes permanent damage.