Embedded programming for LCD interfacing with microcontroller (ATMEL / PIC)

LCD Interfacing - Download PDF

Embedded programming for LCD display Interfacing

(Book: The 8051 Microcontroller an Embedded Systems – using Assembly and C, Muhammad Ali Mazidi, Janice Gillispie Mazidi, Rolin D. McKinlay)

LCD Interfacing

Pin	Symbol	I/O	Description
1.	Vss	-	Ground
2.	Vcc	-	+5V power supply
3.	VEE	-	Power supply to control contrast
4.	RS	I	RS=0 – select command register RS =1 – select data register
5.	R/W	I	R/W=0 – Write R/W=1 – Read
6.	E	I/O	Enable
7.	DB0-DB7	I/O	8-bit data bus

LCD Command Codes

Code (Hex)	Command to LCD instruction register
1	Clear display screen
2	Return home
4	Decrement cursor (shift cursor to left)
6	Increment cursor (shift cursor to right)
5	Shift display right
7	Shift display left
8	Display off, cursor off
A	Display off, cursor on
C	Display on, cursor off
E	Display on, cursor blinking
F	Display on, cursor blinking
10	Shift cursor position to left
14	Shift cursor position to right
18	Shift the entire display to the left
1C	Shift the entire display to the right
80	Force cursor to beginning of 1st line
C0	Force cursor to beginning of 2nd line
38	2 lines and 5×7 matrix

Example Program:

To write/read on the LCD, first a set of commands (from above table) should be sent to the LCD module to set mode and clear display. Below is a set of functions in an order to make you understand easily.

(Don’t consider the item displayed, instead “HELLO!” will be displayed)

LCD Interfacing - Download PDF