Calculator

A simple calculator which can perform Signed operations on 64bits numbers with max of two different math symbols or any number of operands but with the same math symbol.

Author : Maryam Saeedmehr

Language : C

Functionalities

• Can perform (+,-,/,*) operations whether signed or unsigned.
• Generic number of operands with only one math operation like (2225..) : the number of operands can be set before compilation in calculator_blocks.h in (MaxNumberOfOperands) macro
• Only can handle two different math operations like 2*3+10 with priority.
• Almost detecting the user mistyping and throw exception .

Requirement

For implementing this code yourself, You Need to install below applications :

• Atmel Studio
• Proteus
• 4 * 4 keypad interface
• 16*2 LM016L LCD interface
• Avr Atmega32

The main Workflow of the program

This is just a general explaintion of what you will see in the code but the code is already commented when needed to be able to trace it

• calculator.c contains globel flag which can contain state of the program flow inside the code in enum var as defined in calculator_blocks.h: enum StageFlag{Reset,StartPoint,AnalyzePoint,CalculatePoint,DisplayPoint,ErrorPoint}; and by that i cannot move to the next stage until i complete the previous stage correctly with a flag is set to the next value when sucess.

• the next idea is that my uint8 KeyPad_getPressedKey(); returns one byte of data[0..9] but if the user enters 54578,how i convert it to valuable data to make operations on it? this is done using a simple math trick: * storing the keypad inputs in MyArr for instance * then taking the last element MYArr[len-1] + MyArr[len-2]*10 +..+MyArr[len-i]*PowerOf(10,i)= Valuable Number to use( it's deciaml number of base 10 :) )

• When the application starts, i stored all the inputs coming from the user inside an array using GetData(); then i analyze it using Analyze() and seperate the operands in another array and the operations as well.

• then i do the required operation in calculate(); then display if the input is valid.

• Higher range number(greater than signed 32bits) weather inputs or a result won't display on the LCD correctly due to the limiation in itoa.c standard function, so i modifiy it to LCD_Signed_Int64_ToString function :) .

Step1 : Create the C code in Atmel Studio

Create a new project in the atmel studio and copy all files in the /Codes folder into your new project folder .

Step2 : Build your project

After you have built it , a Calculator.hex file will be created in your project's folder. This is the only thing you need to program your avr in the proteus.

Step3 : Create your circuit

Use proteus to emulate your circuit. Try to make it as I have done....

Step4 : Program Atmega32

To ptogram your microcontroler in the proteus , just double click on it and choose the .hex file and press OK !

Step5 : Enjoy It

Files

• /Codes : This is the main folder consists of :
  • /Codes/SourceCodes/std_types.h : Contains new types of standards data types
  • /Codes/calculator_blocks.h : Contains the configuarion you set to how much the calculator can handle number of operands,operation
  • /Codes/calculator_blocks.c : Contains the main work of the calculator as will be explain later
  • /Codes/Calculator.c : the main of the application
  • /Codes/SourceCodes/lcd.c : normal c driver
  • /Codes/SourceCodes/keypad.c : normal c driver
• /Calculator.pdsprj : Simulation file using proteus
• /LICENSE : The license of this project

Support

Reach out to me at one of the following places!

• Telegram at @BitterOcean
• Gmail at [email protected]

License