Programmable pins used as digital inputs or outputs.
General-purpose I/O pins configured as input (with pull-up/down) or output (push-pull/open-drain) via registers. Read buttons, drive LEDs, bit-bang protocols. Respect current limits per pin; use transistors for loads. Alternate functions connect peripherals.
Setting a bit in the port output register turns an LED on.
General-purpose I/O pins are the basic link between a microcontroller and the real world, so their configuration decides what a board can do.
Programmable pins used as digital inputs or outputs.
General-purpose I/O pins are the basic link between a microcontroller and the real world, so their configuration decides what a board can do.
A push-pull output drives both high and low. An open-drain output only pulls low, so an external pull-up is needed and it allows wired connections.
Each pin and port has a maximum current, so driving a motor or a bright LED directly can damage the pin or the chip.
Typical applications include driving an LED from a GPIO pin with a series resistor, reading a push button with an internal pull-up resistor and toggling a pin to bit-bang a custom protocol.
Study "Interrupts" first (topic 60 of 104 in Electronics & Embedded). It covers the groundwork this topic builds on.
Pin multiplexing. Debounce. Drive strength.
Setting a bit in the port output register turns an LED on.
The next topic is "Timers and counters", which builds directly on this one.
It is classed as Intermediate in Electronics & Embedded (topic 61 of 104). It is an intermediate topic. Work through the beginner topics in Electronics & Embedded first.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.