1. DIGITAL CALCULATOR USING 8051
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2. Contents: ©Copyright 2016 : make it or take it.in Project overview.
Block diagram.
Components used
Microcontroller.
Power supply
Liquid Crystal Display
Potentiometer
4*4 keypad
Software used.
Circuit diagram.
Working.
Applications.
Future scope.
Conclusion.
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3. Project overview:
It uses 4*4 keypad matrix to take input number or operation sign, controller processes the data n send output to port 2 where LCD is connected.
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4. Block diagram:
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5. Components used - Power supply:
7805
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6. Microcontroller – 8051: Features of 8051 microcontroller
4 KB on chip program memory.
128 bytes on chip data memory(RAM).
128 user defined software flags.
8-bit data bus.
16-bit address bus.
32 general purpose registers each of 8 bits.
16 bit timers (usually 2, but may have more, or less).
3 internal and 2 external interrupts.
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7. MICROCONTROLLER USED AT89S51
The AT89S51 is a low-power, high-performance CMOS 8-bit microcontroller with 4K bytes of In-System Programmable Flash memory.
The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout.
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8. Liquid Crystal Display
LCD (Liquid Crystal Display) is an electronic display module.
A 16x2 LCD is very commonly used in various devices and circuits.
A 16x2 LCD means it has 16 columns and 2 rows for displaying information.
A command is given to LCD to do a predefined task like initializing it, clearing its screen, setting the cursor position, controlling display etc.
The data sent to the LCD is in parallel combination i.e. by using D0 to D7 pins.
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9. It is used to control the brightness of the LCD by connecting it at V0
Potentiometer
A potentiometer, informally a pot, is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider.
Potentiometers consist of a resistive element, a sliding contact (wiper) that moves along the element, making good electrical contact with one part of it, electrical terminals at each end of the element, a mechanism that moves the wiper from one end to the other, and a housing containing the element and wiper.
The potentiometer available are of multiple ranges, in this project the potentiometer used is an 10KΩ
It is used to control the brightness of the LCD by connecting it at V0
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10. 4*4 keypad
The need for 4x4 keypad is to use less lines for the 16 switches. normal method shown uses only 8 lines.
4 lines are output from uC, and connect to each column 4 lines are input to uC and connect to each row.
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11. We used keil uVision5 IDE software for concern project.
Software used:
Microcontrollers mostly use different software's from compiling code or to creating a ‘hex file’ till making its PCB( Printed Circuit Board ).
Integrated Development Environment (IDE) - contains a text editor for writing code, a graphic window (Serial Monitor), a text console, a toolbar with buttons for compiling the code.
We used keil uVision5 IDE software for concern project.
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12. Finally, the fourth stage is performed when the equal sign is pressed.
Working:
A simple calculator takes input from a keypad and displays the answer on a 16*2 LCD display. To build a simple calculator that adds and subtracts, four stages are needed.
The first stage takes the serial input of a number from a keyboard, converts the number into hex, and stores it into memory.
The second stage also takes serial input from the keypad only this time it is an operation key.
The third stage repeats the first stage by storing a second hex number to memory.
Finally, the fourth stage is performed when the equal sign is pressed.
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13. Conclusion:
Digital calculator is yet another simple device which can be used to calculate simple 2 digit number algebraic calculations, using microcontroller interfaced with a LCD can perform various operation which are highly accurate. Thus this project is very suitable for small scale as well as medium scale calculation.
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14. Thanking You
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