RasberryPi

Here is the truth about the Raspberry Pi: it’s a real computer that costs about as much as a meal out, small enough to forget in a drawer and open enough to understand all the way down to the pins. That combination is why it changed how people learn computing.

What it is, in plain words

The Raspberry Pi is a family of single-board computers made by Raspberry Pi Ltd (the trading arm of the UK Raspberry Pi Foundation, an education charity). The first model shipped in 2012. A Pi is a whole computer on one board: an ARM processor (Broadcom system-on-chip), RAM, USB, networking, HDMI output, and – the special part – a 40-pin GPIO header that lets software switch real electrical signals on and off.

The current family, roughly:

• Raspberry Pi 5 (2023) – quad-core Cortex-A76 at 2.4 GHz, 2–16 GB RAM, a PCIe connector for NVMe SSDs, and Raspberry Pi’s own RP1 I/O chip.
• Raspberry Pi 500 / 500+ – a Pi 5 built into a keyboard, like the home computers of the 1980s.
• Raspberry Pi Zero 2 W – tiny and cheap, for embedded projects.
• Compute Modules – the Pi on a small card for building into products.
• Pico / Pico 2 – a different beast: a microcontroller (RP2040 / RP2350 chips) with no operating system, programmed in C, MicroPython or Rust.

The official OS is Raspberry Pi OS (Debian-based, 64-bit by default). Ubuntu, Fedora, Arch Linux ARM, LibreELEC, Home Assistant OS and others run too – and so does Void Linux, which publishes aarch64 images for the Pi.

Why it matters

A Pi lets you own a whole Linux server for the price of a few cups of coffee and a couple of watts of power. People use them as home servers, ad blockers (Pi-hole), media centres, retro game consoles, network monitors, robots, weather stations and classroom computers. More importantly, GPIO lets software touch the physical world, and that’s the moment computing stops being abstract.

An everyday analogy: a Swiss Army knife with a breadboard attached

A laptop is a sealed appliance. A Pi is more like a pocket knife – small, cheap, useful for many jobs – with a set of terminals on the side where you can clip on wires, buttons, lights and sensors. Plug it into a TV and it’s a desktop; leave it headless in a cupboard and it’s a server; wire it to a motor and it’s a robot.

flowchart LR
  SD["microSD / NVMe: OS"] --> SOC["BCM2712 SoC: CPU + GPU"]
  SOC --> RP1["RP1 I/O chip"]
  RP1 --> GPIO["40-pin GPIO: LEDs, sensors, I2C, SPI, UART"]
  RP1 --> USB["USB, Ethernet"]
  SOC --> HDMI["2 x micro-HDMI"]

A hands-on example: a headless Pi and a blinking LED

1. Flash the OS. Use Raspberry Pi Imager (on Void/Arch: rpi-imager from the repos or Flatpak). Choose your board and Raspberry Pi OS Lite (64-bit), then in the settings set hostname, username, Wi-Fi and enable SSH with your public key. Write to the card, insert it, power on.

2. Log in.

ssh vikid@pi.local
sudo apt update && sudo apt full-upgrade -y
cat /proc/device-tree/model     # Raspberry Pi 5 Model B Rev 1.0
vcgencmd measure_temp           # SoC temperature

3. Wire an LED. Connect GPIO 17 (physical pin 11) → 330 Ω resistor → LED long leg; LED short leg → ground (pin 9).

4. Blink it. Use gpiozero, which works on every model including the Pi 5. (The old RPi.GPIO library doesn’t support the Pi 5’s RP1 chip.)

from gpiozero import LED, Button
from signal import pause

led = LED(17)
led.blink(on_time=0.5, off_time=0.5)

button = Button(2)          # optional: button between GPIO 2 and ground
button.when_pressed = led.toggle
pause()

python3 blink.py

Or from the shell with the modern libgpiod tools:

gpioset GPIO17=1                    # LED on until Ctrl-C (libgpiod v2)
pinctrl get 17                      # inspect a pin (Pi's own tool)

5. Give it a job. A few one-command ideas: curl -sSL https://install.pi-hole.net | bash (read the script first!), a Syncthing node, a Git server over SSH, or a PicoLisp web app running on aarch64 – PicoLisp’s tiny footprint suits a Pi perfectly.

Common misconceptions

• “It’s a toy.” A Pi 5 is faster than many laptops from a decade ago and runs real server workloads 24/7.
• “Any phone charger will do.” Under-powering causes random crashes and corrupted cards. Use the official 27 W USB-C supply for the Pi 5.
• “SD cards are fine forever.” They wear out under heavy writes. Use a good card, log to RAM, or boot from an NVMe SSD.
• “Pico is a small Pi.” It’s a microcontroller: no Linux, no files, just your program running on bare metal.
• “GPIO pins are 5 V.” They’re 3.3 V. Connecting 5 V directly can kill the chip.

Connections

• Linux and Linux Tools – everything you’ll use on the Pi.
• Python – the usual language for GPIO projects.
• Cool Hardware – other gadgets worth knowing.
• SSH Login – how you’ll talk to a headless Pi.
• Networking – turning it into a home server.

Links