The 8051 Microcontroller and Embedded

Home Automation, Networking, and Entertainment LabDept. of Computer Scienc

e and Information Engineering

National Cheng Kung University

Chung-Ping Young

REAL-WORLD INTERFACING I LCD, ADC, AND SENSORS

Department of Computer Science and Information EngineeringNational Cheng Kung University

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INTERFACING LCD TO 8051 HANEL

LCD Operation

‰LCD is finding widespread use replacing LEDs¾The declining prices of LCD¾The ability to display numbers, characters, and graphics¾Incorporation of a refreshing controller into the LCD, thereby relieving the CPU of the task of refreshing the LCD¾Ease of programming for characters and graphics

Department of Computer Science and Information EngineeringNational Cheng Kung University

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INTERFACING LCD TO 8051LCD Pin Descriptions HANEL

Pin Descriptions for LCD

DescriptionsGround+5V power supplyPower supply to control contrastRS=0 to select command register, RS=1 to select data registerR/W=0 for write, R/W=1 for readEnableThe 8-bit data busThe 8-bit data busThe 8-bit data busThe 8-bit data busThe 8-bit data busThe 8-bit data busThe 8-bit data busThe 8-bit data busI/O

PinI/OSymbolVSS 1 -- 2 VCC-- VEE-- 3 4 IRS 5 R/WI 6 EI/ODB0 7 I/O 8 DB1I/O 9 DB2I/O 10 DB3I/O 11 DB4I/O 12 DB5I/O 13 DB6I/O 14 DB7

used by the LCD to latch information presented to its data bus

• Send displayed information or instruction command codes to the LCD - Read the contents of the LCD’s internal registers

Department of Computer Science and Information EngineeringNational Cheng Kung University

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INTERFACING LCD TO 8051 HANEL

LCD Command Codes

Force cursor to beginning to 1st line

80

Force cursor to beginning to 2nd line

C0

2 lines and 5x7 matrix

38

Shift the entire display to the right

1C

Shift the entire display to the left

18

Shift cursor position to right

14

Shift cursor position to left

10

Display on, cursor blinking

F

Display on, cursor blinking

E

Display on, cursor off

C

Display off, cursor on

A

Display off, cursor off

8

Shift display left

7

Shift display right

5

Increment cursor (shift cursor to right)

6

Decrement cursor (shift cursor to left)

4

Return home

2

Clear display screen

1

Command to LCD Instruction Register

LCD Command Codes Code (Hex)