8051 microcontroller interfacing with lcd pdf

The idea of 4 bit communication is used save pins of microcontroller. Thus 4 bit mode data transfer is most commonly used. In this LCD each character is displayed in 5x7 pixel matrix. This LCD has two registers. A command is an instruction given to LCD to do a predefined task like initializing, clearing the screen, setting the cursor position, controlling display etc. Data Register- stores the data to be displayed on the LCD.

Therefore before passing any data to LCD, its command register should be read and busy flag should be checked. A high to low pulse is given at EN pin when data is sent. Each write operation is performed on the positive edge of the Enable signal. This microcontroller has 40 pins with four 8-bit ports P0, P1, P2, and P3. Here P1 is used as output port which is connected to data pins of the LCD.

The control pins pin are controlled by pins of P0 port. Pin 3 is connected to a preset of 10k to adjust the contrast on LCD screen. A16x2 LCD display is very basic module and is very commonly used in various devices and circuits. These modules are preferred over seven segments and other multi segment LEDs. A 16x2 LCD means it can display 16 characters per line and there are 2 such lines.

The command register stores the command instructions given to the LCD. A command is an instruction given to LCD to do a predefined task like initializing it, clearing its screen, setting the cursor position, controlling display etc.

The data register stores the data to be displayed on the LCD. It can be erased and program to a maximum of times. All these ports are 8-bit bi-directional ports i. Except P0 which needs external pull-ups, rest of the ports have internal pull- ups. When 1s are written to these port pins, they are pulled high by the internal pull-ups and can be used as inputs. These ports are also bit addressable and so their bits can also be accessed individually. Port P0and P2are also used to provide low byte and high byte addresses, respectively, when connected to an external memory.

It can be programmed to operate at different baud rates. Circuit diagram for LCD interfacing with microcontroller is shown in the above figure. I have used these Pins in above circuit. And control pins RS, RW and E to the pin 12,13,14 pin 2,3,4 of port 3 of microcontroller respectively.

Pin 3 V0 is connected to voltage Vcc through a variable resistor of 10k to adjust the contrast of LCD. Middle leg of the variable resistor is connected to PIN 3 and other two legs are connected to voltage supply and Ground. Function msdelay has been created to create delay in milliseconds and called frequently in the program, it is called so that LCD module can have sufficient time to execute the internal operation and commands.

Please refer this: Getting Started with Microcontroller. Check your circuit connections again. Agree with you harish kumar If you got the solution kindly share with us. Thanku for ur explanation and code. Can u tell me how to store multiple strings into LCD? Hello circuit digest! The above video shows lcd interface on bread board Can this project be shown on general purpose board??? Also on pcb??? Very useful article. Get Our Weekly Newsletter! Helena St. Related Content. Controlling Light using Touch Sensor and Microcontroller.

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