raspberry-pi-projects

Personal Raspberry Pi projects and experiments with sensors, automation, and Python.

Raspberry Pi 3 — Sensor & Control Circuits

This repository contains a series of educational circuits developed on the Raspberry Pi 3 to demonstrate fundamental principles of electronics, GPIO programming, and sensor control using Python.

It includes hardware, software, and four circuits, designed for clarity and educational presentation.

Hardware Overview

• Model: Raspberry Pi 3 Model B
• CPU: Quad-core 1.2GHz processor
• GPU: Dual-core VideoCore IV
• RAM: 1GB
• Ports: 4× USB, HDMI output, 40× GPIO pins
• Power: Micro USB (5V)

Software Setup

• Operating System: Raspberry Pi OS (Linux)
• Programming Language: Python 3
• IDE: PyCharm / Thonny / Visual Studio Code
• Terminal Access: via HDMI or SSH

Tools

• PuTTY – terminal emulator for remote access
• PyCharm – IDE for Python development

Circuits Overview

1. LED Control with Push Button

File: button_led.py

• Goal: Toggle an LED using a push button.
• Connections:
  • LED → GPIO 17 → GND
  • Button → GPIO 27 → 3.3V
• Library: RPi.GPIO
• Description: Demonstrates basic GPIO input/output interaction.

2. Temperature-Based LED Control (DHT22 Sensor)

File: temp_led_control.py

• Goal: Light up LEDs based on DHT22 temperature readings.
• Connections:
  • DHT22 → GPIO 17, 5V, GND
  • LED1 → GPIO 20, GND
  • LED2 → GPIO 21, GND
• Logic:
  • Temp < 25°C → LED1 ON
  • Temp ≥ 25°C → LED2 ON
• Library: Adafruit_DHT

3. Relay Activation on Fault Condition

File: relay_led_fault.py

• Goal: Simulate a system fault that triggers a relay and LED alert.
• Connections:
  • Relay → GPIO 17, 5V, GND
  • LED → GPIO 4, GND
• Library: RPi.GPIO

4. LED Brightness Control via Potentiometer (PWM + ADS1115)

File: pwm_led_ads1115.py

• Goal: Control LED brightness using a potentiometer via ADS1115 ADC.
• Connections:
  • ADS1115 → VDD (3.3V), GND, SDA (GPIO 2), SCL (GPIO 3)
  • Potentiometer → 3.3V, GND, A0
  • LED → GPIO 18 (PWM), GND
• Library Installation:

  pip3 install adafruit-circuitpython-ads1x15

• Description: Reads the analog value from the potentiometer and maps it to LED brightness using PWM.

Running the Code

1. Clone the Repository

git clone https://github.com/<your-username>/raspberrypi-projects.git
cd raspberrypi-projects

2. Install Dependencies

sudo apt-get update
sudo apt-get install python3-pip
pip3 install RPi.GPIO Adafruit_DHT adafruit-circuitpython-ads1x15

3. Run a Script

python3 button_led.py

4. Stop Execution Safely

Press Ctrl + C

Tools & Components

• Breadboard and jumper wires
• LEDs and resistors (330Ω)
• DHT22 temperature and humidity sensor
• Relay module
• Potentiometer (10kΩ)
• ADS1115 ADC module

Author

[Kalliopi Angeli]

License

Licensed under the MIT License.
Free for educational use, modification, and distribution.