Hex Keypad interfacing with 8051

Hex Keypad interfacing with 8051
commented till here -->

Keypad Interface
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Embedded system design


Hex Keypad and LCD interfacing with microcontroller

For any micontroller based device, the LCD forms one of the best ways to interact with its users. Here the LCD with HD440780, controller has been interfaced to an 8051 microcontroller. The controller used it 89c52, and the LCD is JHD 162a, 16 x 2 (16 characters x 2 lines)



The LCD has 3 control pins:
RS: Register select [To select Command (RS = 0) or Data register (RS = 1)]
R/W: Read/Write [To send Read (R/W = 1) or write command (R/W = 0)]
E: Enable [To latch the data and command to LCD (High to Low transistion)]

The LCD has 8 data pins:
The data pins are: DB0 to DB7
Pins on LCd are Pin-7 to Pin-14

Other connections:' The LED+ and LED- pins of LCD are used for the Backlight of LCD.
Vcc, Vee and Vss of LCD are used for powering the LCD and controlling the contrast of LCD


Hex Keypad and LCD interface diagram