We'll configure a GPIO pin as a plain digital input, read the PIR module's output, and react to it, lighting an LED and printing over UART when motion is detected. This is about as basic as digital sensor reading gets, a good one to have in your back pocket before moving on to trickier analog and protocol-based sensors.

3. Prerequisite

3.1 Hardware

• STM32 Nucleo-F070RB development board

• HC-SR501 (or similar) PIR motion sensor module

• Breadboard and jumper wires

• Micro-USB cable

• PC with PuTTY

3.2 Software

• STM32CubeMX (standalone)

• STM32CubeIDE

• ST-LINK USB driver

• PuTTY, or an equivalent serial terminal app