The Raspberry Pi 5 has a 40-pin GPIO (General Purpose Input/Output) header that lets you connect the Pi to the physical world.

There are different types of pins:

• GPIO Pins – These can be programmed to send or receive signals. They're used to turn things on or off or detect if a button has been pressed.
• Power Pins – Provide constant 3.3V or 5V power to components like sensors or displays. The Raspberry Pi 5 has two 5V pins (2 and 4), and two 3.3V pins (1 and 17).
• Ground (GND) Pins – These complete the circuit by connecting your components to the Pi's ground. The ground pins are 6, 9, 14, 20, 25, 30, 34, 39.
• Special Function Pins – Some GPIO pins also support communication protocols like I2C, SPI, and UART, which are used for more advanced components like displays or GPS modules.

The special function pins include:

I2C (Inter-Integrated Circuit)

A simple two-wire connection used to communicate with sensors, displays, and other low-speed devices. Great for
connecting multiple devices using just two pins.

SPI (Serial Peripheral Interface)

A faster connection used for high-speed communication with things like touchscreens, SD cards, and sensors.
Uses multiple pins but is very reliable for data-heavy devices.

UART (Universal Asynchronous Receiver/Transmitter)

A basic serial connection, often used to communicate with GPS modules, other microcontrollers, or for debugging. Uses just two pins: one for sending and one for receiving.

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A reference guide to pinouts can be accessed directly on the Raspberry Pi including the Pi 5. Open the command terminal and type pinout, then press enter.