📚 Section 1 – Fundamentals & Python Libraries for GPIO and IoT

🔘 Push Buttons & GPIO Input

A push button is a simple switch that connects or disconnects a circuit when pressed. Most breadboard push buttons have 4 pins:

• Pins A & B are internally connected.
• Pins C & D are internally connected.
• Pressing the button connects A→C and B→D.

When connected to a Raspberry Pi GPIO pin:

• One side of the button gets 3.3V.
• The other side connects to a GPIO pin.
• A pull-down resistor ensures the pin reads LOW (0) when not pressed.
• Pressing the button sends HIGH (1) to the pin.

🔔 Active Buzzer & GPIO Output

An active buzzer produces a tone when powered. Unlike a passive buzzer, it does not need PWM signals to generate sound.

• Connect VCC to 3.3V or 5V.
• Connect GND to ground.
• Control sound by sending HIGH/LOW signals to the GPIO pin.

📦 My Journey into Full Stack IoT

My journey into Full Stack IoT started with a simple goal: Master hardware and software integration before university resumed. Since I already had a background in Python, I chose the Raspberry Pi over Arduino. Arduino is excellent for microcontroller projects, but the Pi gave me the flexibility of a full Linux environment, Python support, and the ability to handle more complex IoT systems.

I ordered my Raspberry Pi B+ Model from Direnc.net, a popular electronics store in Turkey. My excitement turned into panic when the Pi wouldn’t turn on. I had used a normal phone charger instead of the recommended Pi power supply. The Pi requires 5.1V and 2.5A for stable operation, but my phone charger was underpowered. I even bought a Raspberry Pi Pico thinking I had fried the board, only to discover the issue was just insufficient current. Lesson learned: always check power requirements first!

Once I got the proper power supply, the Pi booted perfectly. I installed Raspberry Pi OS using the official imager and booted into Linux for the first time. I began exploring the terminal with commands like cd, ls, sudo, pwd, and mkdir. Soon, I was ready to start coding with Thonny IDE and controlling my first LED.

This early stage was full of small mistakes, but each taught me something new. Now I feel more confident in handling hardware, software, and Linux basics. My plan is to document everything—not only the successes but also the struggles— so that I can look back on my growth and help beginners relate to the journey.

🔌 Raspberry Pi B+ / 400 GPIO Pinout

Understanding the GPIO pins is essential for connecting LEDs, buttons, and sensors. Here's the pinout diagram of my Raspberry Pi 3B+ (similar to the Pi 400):

💡 Section 3 – GPIO Projects

This section contains all my beginner GPIO projects using the Raspberry Pi. Here, I experiment with controlling LEDs, buttons, and basic electronic components using Python libraries like RPi.GPIO and GPIOZero.

🔹 Project 1: Blinking Two LEDs – My first hands-on GPIO project using Python. 🔹 Project 2: 4 LEDs & 5 Buttons – A small reaction-style game with multiple GPIO inputs and outputs. 🔹 More Projects Coming Soon – I will update this section as I explore motors, sensors, and interactive IoT systems.

Check the Projects Menu for detailed write-ups and demos of each GPIO project.

🎯 🎮 GPIO Project 3: LED Roulette Game with Raspberry Pi

This project is a fun little game built using a Raspberry Pi, a set of LEDs, push buttons, and Python. The goal is simple: spin the roulette of LEDs, press the stop button, and try to land on the “lucky” LED to score points! Your scores are saved between rounds, so you can keep improving over time.

💡 Tip: This is a great beginner-friendly Raspberry Pi GPIO project that teaches you about LED control, button inputs, random number generation, and persistent storage in Python.

📜 How It Works

1. When you start the game, the program randomly selects one LED to be the “lucky” LED.
2. The LEDs then start lighting up in a fast sequence, like a spinning roulette.
3. When you press the stop button, the LEDs freeze on one position.
4. If you land on the lucky LED, you earn a point!
5. Your score is saved using a small local database, so it remembers you between plays.

🛠 Components Needed

• Raspberry Pi (any model with GPIO pins)
• 10 LEDs
• 10 suitable resistors (220Ω recommended)
• 2 push buttons
• Jumper wires & breadboard
• Python 3 installed on your Raspberry Pi

💻 The Code

The code below controls the LED roulette. It uses the gpiozero library for easy GPIO handling and shelve to store scores.

💾 View Python Code & Download →

🚀 How to Run

1. Install the gpiozero library if you haven’t already:

   pip install gpiozero

2. Save the Python code to a file, for example led_roulette.py.
3. Wire up your LEDs and buttons according to the led_pins list in the code.
4. Run the program:

   python3 led_roulette.py

5. Follow the instructions on the terminal, start the roulette, and try to stop on the lucky LED!

⚠️ Safety Note: Always power off your Raspberry Pi when making changes to your wiring to avoid short circuits.

🎯 Final Thoughts

This project is a fun way to mix Python programming with hands-on electronics. It’s also a perfect example of how you can add a competitive twist to simple hardware projects by introducing scoring, randomness, and persistent data storage.

My 5 Buttons & 4 LEDs Game Circuit on a Breadboard

🎮 GPIO Project 2: 5 Buttons & 4 LEDs Game

This project is an **interactive LED guessing game** built with a Raspberry Pi, 4 LEDs, 5 push buttons, and a passive buzzer. It combines inputs (buttons) and outputs (LEDs & sound) to create a fun, hands-on GPIO challenge. The goal is to guess which LED the Raspberry Pi randomly selects in each round.

🕹 How the Game Works

1️⃣ Press the **Start Button** to begin the game. 2️⃣ Enter your **name** in the terminal to personalize the score. 3️⃣ The Raspberry Pi **randomly chooses one of the 4 LEDs**, but keeps it secret. 4️⃣ Use the 4 LED buttons to make your guess. When a button is pressed:

• The corresponding LED lights up to show your selection.
• If correct: ✅ +5 points and a **double beep** plays on the buzzer.
• If wrong: ❌ -2 points and a **single low beep** plays.

5️⃣ The game runs for **5 rounds**, tracking your score after each guess. 6️⃣ At the end, your **total score** is displayed and stored in a Python Shelve database for future reference.

🔧 Components Used

• Raspberry Pi B+ Model
• Breadboard & Jumper Wires
• 4× LEDs (Red, Green, Blue, Yellow) + 220Ω resistors
• 5× Push Buttons (4 for guesses, 1 as the start button)
• 1× Passive Buzzer (for audio feedback)

📚 Circuit Explanation

If you want to understand how push buttons and active buzzers are wired and work, check the Fundamentals Section → Push Buttons & GPIO Input.

My 5 Buttons & 4 LEDs Game Circuit on a Breadboard

🧠 Game Logic in Python

- The game uses the random module to select a secret LED each round. - Player input is captured via GPIO button presses. - Scoring: +5 for correct guess, -2 for wrong guess. - Sound Feedback:

• Double short beeps = Correct
• Single long beep = Wrong

-Storage: Player name and score are saved using shelve for local storage.

💾 View Python Code & Download →

    import RPi.GPIO as GPIO
    import time
    
    GPIO.setmode(GPIO.BCM)
    
    led1 = 17
    led2 = 27
    
    GPIO.setup(led1, GPIO.OUT)
    GPIO.setup(led2, GPIO.OUT)
    
    try:
        while True:
            GPIO.output(led1, GPIO.HIGH)
            GPIO.output(led2, GPIO.LOW)
            time.sleep(1)
    
            GPIO.output(led1, GPIO.LOW)
            GPIO.output(led2, GPIO.HIGH)
            time.sleep(1)
    except KeyboardInterrupt:
        GPIO.cleanup()