Arduino Calculator

Electronic Calculator using Arduino UNO R3

2. Objectives

• To build a basic calculator (addition, subtraction, multiplication, division) using Arduino UNO R3 as the main controller.
• To study how to interface a Keypad with Arduino for user input.
• To learn programming in Arduino IDE to process input and display results.
• To design a portable calculator powered by a 9V battery.

3. Components Used

1. Arduino UNO R3
2. 4x4 Keypad (for numbers and operators)
3. Switch (Power ON/OFF)
4. 9V Battery with connector
5. Jumper wires and Breadboard
6. LCD (16x2) or OLED Display [for showing results]

4. Working Principle

• When the switch is turned ON, the 9V battery powers the Arduino UNO R3 board.
• The user presses numbers and operators on the Keypad → Arduino reads the signals.
• Arduino processes the input and performs calculations (+, −, ×, ÷).
• The result is displayed on the LCD/OLED screen (or Serial Monitor if no display is used).
• A “Clear” button can reset the input to start a new calculation.

5. Scope of Work

• Supports only basic arithmetic operations: addition, subtraction, multiplication, division.
• Works with integer numbers (basic level, no complex equations).
• Powered by a 9V battery for portability.

6. Benefits

• Can be used as a prototype for a simple electronic calculator.
• Enhances knowledge of microcontrollers and C++ programming on Arduino.
• Improves skills in circuit design and embedded system development.