Arduino Powered 4-Speed Fan with Auto Shutoff

As the name implies, the Arduino 4-Speed Fan is just that - a fan that has 4 speeds. The speed can be set using either the keypad or dedicated buttons. As a safety feature, the fan is equipped with an ultrasonic sensor, and will automatically turn off if any object is detected within 10 cm of the sensor.

Demo Video

Hardware Components Used

• 1x Elegoo UNO R3 Microcontroller (ATmega328P)
• 1x Breadboard
• 2x Buttons
  • 1x PULLDOWN Configuration (X)
  • 1x PULLUP Configuration (Y)
• 1x 1k Ohm Resistor
• 4x LEDs
• 5x 220 Ohm Resistors
• 1x Diode Rectifier 1N4007
• 1x NPN Transistor PN2222
• 1x Fan Attachment
• 1x DC Motor
• 1x 4x4 Keypad
• 1x Ultrasonic Sensor
• 21x Wires

Software Libraries Used

• Keypad Library for Arduino (Keypad.h)
  • Used for setting up, defining, and reading the keypad inputs/buttons.
  • Used the makeKeymap() function to set up and define the buttons on the 4x4 keypad. Used the getKey() function to read the keypad inputs/buttons.
  • The software library allowed me to read user inputs from the keypad and adjust the fan speed based on the input.

Wiring Diagram