interface lcd and keypad with 8051 micro

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Interface lcd and keypad with 8051

microcontroller in C

Post on October 23, 2012 by Technology tagged: Interface lcd and keypad with 801

!icrocontroller , "i!#lation for Interface keypad with 801 !icrocontroller , "i!#lation for

Interface lcd and keypad with 801, "i!#lation for Interface lcd and keypad with 801!icrocontroller , "i!#lation for Interface lcd with 801

To interface lcd and keypad with 801 !icrocontroller in $ , we first need few hardware and a

software%Software : &o# need a co!piler, here i #sed a keil co!piler%&o# also #sed other $ co!piler%

Hardware : 'hen yo# done yo#r progra!!ing, yo# definitely want to see it in action% 'ell for

that we need so!e harware co!ponents%

1% (cd 1)*22% 801 !icroprocessor + I #sed t8-c1 of t!el

3% .eypad /*/

/% Two 33p $apacitors% One 0%1# $apacitor and 10k register

Interface lcd and keypad with 8051 microcontroller in C

language & Simulation

This post proides the keypad interfacing code #sing c lang#age for 801 !icro4controller e4g for T8-$1 or T8-$2 etc % This code is written in s#ch a way that, when we press any key

on the keypad then that al#e is displayed on the ($5%

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http://straight2masti.com/tag/simulation-for-interface-keypad-with-8051-microcontroller

http://straight2masti.com/tag/simulation-for-interface-lcd-and-keypad-with-8051



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http://straight2masti.com/tag/simulation-for-interface-lcd-with-8051





Interface lcd and keypad #sing T8-$1

crystal of 11%0-2 67 is #sed here% &o# can #se any crystal al#e fro! 3 to 2/67 with

801% s we know that 801 !icro controller has an architect#re which e9ec#tes an instr#ctionin 12 $P cycles ;1<, hence this 11%0-26h crystal !akes this 801 r#n at 0%-2 6IP" 6illion

of instr#ctions per second%

Port 2 is being #sed to write data on the ($5% lso, P3%= pin is #sed as >" >egister "elect for

($5 and P3%) pin is #sed as ? ?nable pin for ($5% Port 1 is #sed here to interface the keypad%P1%0 to P1%3 pins are #sed for the rows and P1%/ to P1%= are #sed for the col#!ns of the keypad%

Interface Keypad with 8051 microcontroller in c language

How to detect preed key !alue "

'hen key 1 is pressed then >ow$ wire is shorted with $1 wire inside the keypad% "i!ilarly,when key - is pressed then >ow wire is shorted with $3 wire% This behaior is tr#e for all the

keys% Then the ne9t @#estion is, how to detect this behaior in the !icro4controller code A



'e can detect pressed key al#e in the !icro4controller #sing the B"canning lgorith! $odeC%

This algorith! is written with the na!e of D>?5E"'IT$7?"F f#nction in the code% This

f#nction is shown belowchar >?5E"'IT$7?"oid

G

>ow H 1 >owJ H 1 >ow$ H 1 >ow5 H 1 KKTest >ow >ow H 0

if $1 HH 0 G delay10000 while $1HH0 ret#rn F=L M

if $2 HH 0 G delay10000 while $2HH0 ret#rn F8L Mif $3 HH 0 G delay10000 while $3HH0 ret#rn F-L M

if $/ HH 0 G delay10000 while $/HH0 ret#rn DKF M

>ow H 1 >owJ H 1 >ow$ H 1 >ow5 H 1 KKTest >ow J

>owJ H 0if $1 HH 0 G delay10000 while $1HH0 ret#rn F/L M

if $2 HH 0 G delay10000 while $2HH0 ret#rn FL M

if $3 HH 0 G delay10000 while $3HH0 ret#rn F)L Mif $/ HH 0 G delay10000 while $/HH0 ret#rn D9F M

>ow H 1 >owJ H 1 >ow$ H 1 >ow5 H 1 KKTest >ow $

>ow$ H 0

if $1 HH 0 G delay10000 while $1HH0 ret#rn F1L Mif $2 HH 0 G delay10000 while $2HH0 ret#rn F2L M

if $3 HH 0 G delay10000 while $3HH0 ret#rn F3L M

if $/ HH 0 G delay10000 while $/HH0 ret#rn D4F M

>ow H 1 >owJ H 1 >ow$ H 1 >ow5 H 1 KKTest >ow 5

>ow5 H 0if $1 HH 0 G delay10000 while $1HH0 ret#rn D$F M

if $2 HH 0 G delay10000 while $2HH0 ret#rn F0L M

if $3 HH 0 G delay10000 while $3HH0 ret#rn DHF Mif $/ HH 0 G delay10000 while $/HH0 ret#rn DNF M

ret#rn DnF KK 6eans no key has been pressed

M

Interface lcd and keypad with 8051 microcontroller in C language

Complete #rogram :

incl#de

incl#de

KK#nction declarations

oid cctEinitoid

oid delay#nsigned int



writedatas

sNN

MM

oid 7o!eoidG

writec!d0902delay200

M

oid cctEinitoid

GP0 H 0900 KKnot #sed

P1 H 09f0 KK#sed for generating o#tp#ts and taking inp#ts fro! .eypad

P2 H 0900 KK#sed as data port for ($5

P3 H 0900 KK#sed for >" and ?M

oid delay#nsigned int a

Gint i

foriH0i

M

oid writedatachar tG

>" H 1 KK This is dataP2 H t KK5ata transfer ? H 1

delay10

? H 0delay10

M

oid writec!dint

G>" H 0 KK This is co!!and

P2 H KK5ata transfer

? H 1delay10

? H 0

delay10

M



oid lcdinitoid

G

delay1000writec!d0930

delay/00writec!d0930

delay300writec!d0930

delay)0

writec!d0938 KKf#nction set

writec!d090f KKdisplay on,c#rsor off,blink onwritec!d0901 KKclear display

writec!d090) KKentry !ode, set incre!ent

M

char >?5E"'IT$7?"oid

G

>ow H 1 >owJ H 1 >ow$ H 1 >ow5 H 1 KKTest >ow

>ow H 0if $1 HH 0 G delay10000 while $1HH0 ret#rn = M

if $2 HH 0 G delay10000 while $2HH0 ret#rn 8 M

if $3 HH 0 G delay10000 while $3HH0 ret#rn - Mif $/ HH 0 G delay10000 while $/HH0 ret#rn K M

>ow H 1 >owJ H 1 >ow$ H 1 >ow5 H 1 KKTest >ow J

>owJ H 0if $1 HH 0 G delay10000 while $1HH0 ret#rn / Mif $2 HH 0 G delay10000 while $2HH0 ret#rn M

if $3 HH 0 G delay10000 while $3HH0 ret#rn ) M

if $/ HH 0 G delay10000 while $/HH0 ret#rn 9 M

>ow H 1 >owJ H 1 >ow$ H 1 >ow5 H 1 KKTest >ow $>ow$ H 0


if $2 HH 0 G delay10000 while $2HH0 ret#rn 2 Mif $3 HH 0 G delay10000 while $3HH0 ret#rn 3 M

if $/ HH 0 G delay10000 while $/HH0 ret#rn 4 M

>ow H 1 >owJ H 1 >ow$ H 1 >ow5 H 1 KKTest >ow 5

>ow5 H 0if $1 HH 0 G delay10000 while $1HH0 ret#rn $ M


if $3 HH 0 G delay10000 while $3HH0 ret#rn H Mif $/ HH 0 G delay10000 while $/HH0 ret#rn N M

interface lcd and keypad with 8051 micro

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