Welcome to the Hobitronics mini-project series! This repository contains three exciting Arduino-based projects designed for beginners and intermediate learners to explore touch and light sensors. Each project includes full code, explanations, and YouTube Shorts demos.
Description:
This project uses a metal touch sensor to cycle through 8 beautiful colors on an RGB LED every time you touch it.
- Arduino UNO
- RGB LED (Common Cathode or Anode)
- Metal Touch Sensor Module
- Resistors (220Ω for RGB LED)
- Jumper Wires & Breadboard
- Cycles through 8 preset colors with each touch
- Uses PWM to control LED color mixing
- Debounced for stable interaction
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
Control the brightness of a single LED using a touch sensor! Each touch cycles through 5 brightness levels from dim to full brightness.
- Arduino UNO
- LED
- Metal Touch Sensor
- 220Ω Resistor
- Jumper Wires & Breadboard
- 5 levels of brightness (0 to 255)
- PWM used to control LED intensity
- Simple and intuitive interface
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
Use an LDR (Light Dependent Resistor) module to detect ambient light and automatically turn an LED ON or OFF.
- Arduino UNO
- LDR Sensor Module (with digital output)
- LED (or use built-in LED on pin 13)
- Jumper Wires
- Detects light vs. dark environments
- Digital input means no analog processing needed
- Can be extended for street light automation
Description:
This simple yet powerful project uses a flame sensor to detect fire and automatically turns on an LED as an alert. It’s a great beginner-friendly safety project!
- Arduino UNO
- Flame Sensor (Digital Out – D0)
- LED
- Resistor (220Ω for LED)
- Jumper Wires & Breadboard
- Detects flame using a digital flame sensor
- Turns on an LED when fire is detected
- Real-time flame detection output on Serial Monitor
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
This project reads the analog X and Y axis values of a joystick module and lights up different LEDs based on direction (up, down, left, right). A fun and interactive way to learn about analog input and conditional logic!
- Arduino UNO
- Joystick Module (2-axis)
- 4 LEDs (Green, Red, Blue, White)
- 220Ω Resistors (one per LED)
- Jumper Wires & Breadboard
- Detects direction based on joystick tilt
- Lights up a corresponding LED
- Real-time analog value monitoring via Serial Monitor
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
A fun and challenging memory game built using LEDs, push buttons, and a buzzer! The player must repeat an ever-growing sequence of LED flashes. If you press the wrong button — game over!
- Arduino UNO
- 4 Push Buttons
- 4 LEDs (any colors)
- 4 × 220Ω Resistors (for LEDs)
- 4 × 10kΩ Resistors (for buttons, optional if using
INPUT_PULLUP) - Buzzer
- Jumper Wires & Breadboard
- Random sequence generation up to 100 steps
- LED + buzzer feedback for each step
- Detects wrong input and restarts the game
- Perfect for practicing arrays, logic, and interaction
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
A simple mini synthesizer using four push buttons to play different musical notes through a buzzer. Press any button to play a tone!
- Arduino UNO
- 4 Push Buttons
- Buzzer
- Jumper Wires & Breadboard
- Plays 4 distinct notes (C, D, E, G)
- Uses internal pull-up resistors for buttons
- Immediate audio feedback with buzzer
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
This project uses a rotary encoder to count rotations and display the count on a 16x2 LCD screen. Press the encoder button to reset the count.
- Arduino UNO
- Rotary Encoder (with CLK, DT, SW pins)
- 16x2 LCD Display (with LiquidCrystal interface)
- Jumper Wires & Breadboard
- Counts rotary encoder steps (increments/decrements)
- Displays count live on LCD
- Reset count via encoder button
- Uses LiquidCrystal library for easy LCD control
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
This project uses an ultrasonic sensor to detect when a hand is near the dustbin lid, which then automatically opens using a servo motor and closes after a short delay.
- Arduino UNO
- Ultrasonic Sensor (HC-SR04)
- Servo Motor
- Jumper Wires & Breadboard
- Detects hand within 20 cm using ultrasonic sensor
- Opens lid automatically with servo motor
- Closes lid after 2 seconds delay
- Serial monitor outputs distance readings
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
This Arduino project cycles through 30 vibrant RGB colors using a single push button. Each press switches to a new shade by controlling the PWM of red, green, and blue pins.
- Arduino UNO
- RGB LED (Common Cathode)
- Push Button
- Resistors
- Jumper Wires & Breadboard
- 30 distinct colors defined in a 2D array
- Smooth color transition with button press
- Internal pull-up for button debounce
- PWM control for accurate color mixing
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
Description:
This project uses a DHT22 sensor to measure the temperature and humidity, and displays the values on a 16x2 LCD in real-time.
- Arduino UNO
- DHT22 Temperature & Humidity Sensor
- 16x2 LCD Display
- 10KΩ Potentiometer (for LCD contrast)
- Jumper Wires & Breadboard
- Real-time temperature and humidity monitoring
- LCD display output with clear formatting
- Serial monitor output for debugging
- Handles sensor read failures gracefully
👉 Watch on YouTube Shorts
👉 Find Code on GitHub
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License - Use and Modify freely, but please credit Hobitronics if you share!