Raspberry Pi Series
From blinking an LED to a NAS server and AI camera — a full-featured embedded computer
GPIO Basics
Working with the Raspberry Pi's I/O pins.
Raspberry Pi + Button/LED: Intro to GPIO, Interrupts, and Debouncing
An introduction to GPIO input/output on Raspberry Pi using a push button and an LED: basic digital read/write, handling interrupts (event detection), and software debouncing.
Raspberry Pi + Relay: Controlling Electrical Devices via GPIO
Use a 5V single-channel relay to switch electrical devices (lights, fans) on/off via Raspberry Pi's GPIO, with a safety watchdog that auto-shuts-off if left on too long.
Raspberry Pi + PIR: Basic Motion Alarm
Build a basic motion alarm on Raspberry Pi using an HC-SR501 PIR sensor, triggering an LED and buzzer when a person or object moves through its detection zone.
Raspberry Pi + HC-SR04: Measuring Distance via GPIO
Reads distance from 2–400cm using an HC-SR04 ultrasonic sensor over Raspberry Pi's GPIO, with a voltage divider protecting the 5V ECHO pin, using the RPi.GPIO library.
AI Voice Assistant
Voice assistants and natural language processing on Raspberry Pi.
Raspberry Pi + Google Assistant SDK: Basic Voice Assistant
Build a basic voice assistant on a Raspberry Pi 4 with the Google Assistant SDK (gRPC), asking and answering questions via a mic and I2S speaker, activated by a push button.
Raspberry Pi + Text-to-Speech: Speaking Sensor Readings Aloud
Read temperature/humidity from a DHT22 sensor and speak it aloud through an I2S speaker on a Raspberry Pi 4, using pyttsx3/espeak-ng for fully offline speech synthesis.
Camera
Computer vision and camera modules on Raspberry Pi.
Raspberry Pi Camera: Basic License Plate Recognition (ALPR)
Uses a Raspberry Pi 4 + Camera Module v3 and OpenCV (Canny edge detection + contours) to locate a license plate using a geometric heuristic method — an intro step into computer vision, not a production-grade deep-learning ALPR system.
Raspberry Pi Camera: Automatic QR Code/Barcode Scanning
Uses a Raspberry Pi 4 + Camera Module v3 with the pyzbar library and OpenCV to automatically scan QR codes and common barcode formats (EAN-13, Code128, etc.) in real time, logging each scan with a timestamp.
Raspberry Pi + OpenCV: People Counter (Object Detection & In/Out Counting)
Uses a Raspberry Pi 4 and Camera Module v3 with OpenCV's HOG people detector to count people crossing a virtual line, distinguishing in/out direction from each centroid's movement.
AI and IoT Project: Smart Waste Sorting
Use AI, a Raspberry Pi, and various sensors to build a device that recognizes objects and automatically sorts waste, helping raise environmental awareness.