Basic Calculator for 8051

Hello Everyone, Finally I come back after along absence. Today's blog will be about something I like most.  It took from me the last two nights. Fortunately it's required for my next class homework. I hope it could help my colleagues :)

The post provides a simple calculator project code using assembly for 8051 micro-controller. This is a simple one decimal digit calculator which implements only 4 functions: addition(+), subtraction(-), multiplication(x) and division(/).

Code, flowchart and Proteus simulation is given in the 'Downloads' section at the bottom of this page. It is assumed that you know how to interface LCD and keypad with 8051 micro-controller.

The result of the Proteus simulation is shown below.



In the above figure, we can see that a result of "9x9=81" is shown on the screen. To achieve this result, first press '9' from the keypad. Then press 'x' and then press '9' again. After that, on pressing '=' from the keypad the result '81' is automatically displayed on the screen. Then after seconds the screen cleared automatically for next try.

Flowchart

The flowchart describes the main routine and each one of the four subroutines included at the assembly code.

the program acts as follows:

1. Initialize the memory and LCD for display after powering up.


2. Get input form user as " 10/2="


3. Calculate the result depending on the operation once the user press (=)


4. Print the output on LCD

Features of this calculator

• You can give any single digit input from 0 to 9.


• 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 'Error!!' message is displayed. Similarly, 'Error!!' message is displayed if wrong key is pressed instead of a function key.

Downloads

The code was compiled in Kiel uvision 4 and simulation was made in Proteus v7.8 SP2.
To download code , flowchart and proteus simulation click here

How Famous Tech Companies Got Their Names?!

Apple Computers:

It was the favorite fruit of founder Steve Jobs. He was three months late for filing a name for the business, and he threatened to call his company Apple Computers if the other colleagues didn't suggest a better name by 5 o’clock. 

 Google:

The name started as a joke boasting about the amount of information the search-engine would be able to search. It was originally named ‘Googol’, a word for the number represented by 1 followed by 100 zeros. After founders – Stanford graduate students Sergey Brin and Larry Page presented their project to an angel investor; they received a cheque made out to ‘Google’. So, instead of returning the cheque for correction, they decided to change the name to Google. 

Hewlett Packard:

 

Bill Hewlett and Dave Packard tossed a coin to decide whether the company they founded would be called Hewlett-Packard or Packard-Hewlett :D

INTEL:

  Bob Noyce and Gordon Moore wanted to name their new company ‘Moore Noyce’ but that was already trademarked by a hotel chain so they had to settle for an acronym of INTegrated ELectronics.

Microsoft:

Coined by Bill Gates to represent the company that was devoted to MICROcomputer SOFTware. Originally christened Micro-Soft, the ‘-’ was removed later on.

Motorola :

Founder Paul Galvin came up with this name when his company started manufacturing radios for cars. The popular radio company at the time was called Victrola.

SONY:

It originated from the Latin word ‘sonus’ meaning sound and ‘sonny’ as lang used by Americans to refer to a bright youngster.