This post provides a simple calculator implementation for PIC16F84A microcontroller. This is a simple one digit calculator which implements only 4 functions addition(+), subtraction(-), multiplication(x) and division(/). The code for PIC16F84A is written in C language using MPLAB with HI-TECH C compiler. You can download this code from the ‘Downloads‘ section at the bottom of this page.
In this post, it is assumed that you know,
- How to interface keypad with PIC16F84A microcontroller. If you don’t then please read this page.
- How to interface LCD with PIC16F84A microcontroller using only 3 pins. If you don’t then please read this page.
The result of the Proteus simulation is shown below.
In the above figure, we can see that a result of “5×6=30” is shown on the screen. To achieve this result, first press ‘5’ from the keypad. Then press ‘x’ and then press ‘6’ again. After that, on pressing ‘=’ from the keypad the result ’30’ is automatically displayed on the screen.
Features of this calculator
- You can give any single digit input from 0 to 9.
- You can press ‘ON/C‘ button at any time to reset the calculator.
- 4 functions are implemented i-e addition, subtraction, multiplication and division.
- Error messages are displayed if wrong input is detected. For example, if calculator is expecting a number, but a function key is pressed then ‘Wrong Input‘ message is displayed. Similarly, ‘Wrong Function‘ message is displayed if wrong key is pressed instead of a function key.
Main function code
The code for the main function is shown below.
The calculator code for PIC16F84A was compiled in MPLAB v8.85 with HI-TECH C v9.83 compiler and simulation was made in Proteus v7.10. To download code and Proteus simulation click here.
For more detail: PIC16F84A based simple calculator (Code+Proteus simulation)