need help to write code for 8051 : 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes

Forums

8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes :: Forums :: Discuss and Learn :: 8051 Discussion Forum		<< Previous thread \| Next thread >>
need help to write code for 8051

Go to page 1 2 3 ... 16 [17] 18 ... 26 27 28
Moderators: Ajay, Junied , abbas1707, Arun Kumar V, pdi33, Shailesh NAYAK, ۞ TPS ۞, shyam, sashijoseph

Author

Post

sks

Wed Nov 05 2008, 02:01AM

Registered Member #9477

Joined: Thu Jul 31 2008, 07:51AM

Posts: 160
Thanked 0 times in 0 posts

Hi balu,
thanx fr ur valuable suggestion. i m reading AYALA. i m new learner and trying to write code fr 8051 getting a lot of helps from RW.
thanks again
sks

sks

Fri Nov 07 2008, 08:46PM

Registered Member #9477

Joined: Thu Jul 31 2008, 07:51AM

Posts: 160
Thanked 0 times in 0 posts

hello Mr Arun,
good morning. i am waiting fr ur guidance, pl reply.
thanks
sks

sks

Fri Nov 07 2008, 08:54PM

Registered Member #9477

Joined: Thu Jul 31 2008, 07:51AM

Posts: 160
Thanked 0 times in 0 posts

hi pdi,
good morning, hv i don some thing wrong?
plzzzzzzzz reply.
thanks all
sks

Arun Kumar V

Sat Nov 08 2008, 03:35AM

Registered Member #426

Joined: Sun Jan 28 2007, 11:50PM

Posts: 522
Thanked 219 times in 186 posts

Hello sahuji,

i am waiting fr ur guidance, pl reply.

no you haven't done anything wrong, we thought you were out of station or been busy, your last post was on Nov 5th and today you came back.

AVR and 8051 are not the same ( for the time being keep the thought of AVR out of your mind).

So, you are ready for timers, study the basics of timers in your book and of course our tutorial section.
and write a small program using timer

Arun

by the way(BTW), you can check this link : http://www.8051projects.net/forum-t14321-last.html

This post has been thanked 1 time

sks

sks

Sat Nov 08 2008, 09:33PM

Registered Member #9477

Joined: Thu Jul 31 2008, 07:51AM

Posts: 160
Thanked 0 times in 0 posts

hello every body,
good morning all. this is a small code fr hex keypad matrix. this is not working properly
please help by finding errors in the code. this is most urgent.
thanks all
sks

CODE:

;4*4matrix keypad sub routine

        org     00h

stay:

        mov     p1,#0fh

        mov     a,p1

        anl     a,#0fh

        cjne    a,#0fh,stay

here:

        mov     a,p1

        anl     a,#0fh

        cjne    a,#0fh,loop1

        jmp     here

        acall   init

        mov     dptr,#val1

loop1:        

        acall   find

        djnz    r1,loop1

        acall   init

        mov     dptr,#val2

loop2:        

        acall   find

        djnz    r1,loop2

        acall   init

        mov     dptr,#val3

loop3:        

        acall   find

        djnz    r1,loop3

        acall   init

        mov     dptr,#val4

loop4:        

        acall   find

        djnz    r1,loop4

        acall   init

init:

        mov     r1,#04h

        ret

find:

        rrc     a

        jnc     match

        inc     dptr

        ret

match:

        clr     a

        movc    a,@a+dptr

        mov     p2,a

        jmp     stay

val1:

        db 1, 2, 3, 4,

val2:

        db 5, 6, 7, 8

val3:

        db 9, 'a', 'b', 'c'

val4:

        db 'd', 'e', 'f', 0

end

[ Edited Mon Nov 10 2008, 10:22AM ]

pdi33

Sun Nov 09 2008, 06:44AM

Registered Member #1329

Joined: Mon Jun 04 2007, 09:28AM

Posts: 770
Thanked 185 times in 180 posts

sks wrote ...

hi pdi,
good morning, hv i don some thing wrong?
plzzzzzzzz reply.
thanks all
sks

hi sks,
why on earth do u think u have done something wrong???

In fact , u have been very focused and determined in ur objective which is obvious from ur progress.
btw, u and ur nephew are really progressing looking at ur keypad routine. have u tested it yet? what is the problem u r facing?

* inspired to develop,developing to inspire *

This post has been thanked 1 time

sks

sks

Sun Nov 09 2008, 08:29AM

Registered Member #9477

Joined: Thu Jul 31 2008, 07:51AM

Posts: 160
Thanked 0 times in 0 posts

hi,pdi
thanks fr the reply. my nephew is taking a short term course in EMBEDDED SYSTEMS at ISM in BANGALORE. i hv come to meet him & my son. he asked me to help, but u know i hv not yet written keypad subroutine . so i posted the code. i hv tested the code, its showing erratic values, and showing different values by pressing a single switch in each press. i don't understand his logic. if u can help him by solving his problem, it will be a great help. thanks
sks

pdi33

Mon Nov 10 2008, 08:28AM

Registered Member #1329

Joined: Mon Jun 04 2007, 09:28AM

Posts: 770
Thanked 185 times in 180 posts

hi sks,
i too m am not getting the logic for the posted code . can u give the connection of the keypad to the uC?do note that 'a' will return the ASCII code of 'a' back to the variable and not the hex value . For that u have to declare 0x0a in the table.

anyways , glad to see that the whole family is into embedded programming.I would like to give our best wishes to ur nephew and son.

* inspired to develop,developing to inspire *

This post has been thanked 1 time

sks

Ajay

Mon Nov 10 2008, 10:24AM

Rickey's World Admin

Registered Member #1

Joined: Fri Feb 24 2006, 04:56AM

Posts: 4042
Thanked 753 times in 712 posts

sks never forget to mention the behavior of the program on hardware.. well from what you told..

sks wrote ...

its showing erratic values, and showing different values by pressing a single switch in each press

it seems that scanning of keypad is not proper. It may also because of hardware design. So its better if you can provide the circuit. Do label the rows and columns.

www.rickeyworld.info
If you feel satisfied with the user's forum reply please click on the thank button.

Obey forum rules!
Respect others!

This post has been thanked 1 time

sks

sks

Mon Nov 10 2008, 07:48PM

Registered Member #9477

Joined: Thu Jul 31 2008, 07:51AM

Posts: 160
Thanked 0 times in 0 posts

hi pdi,
good morning, i was busy fr the whole day, sorry i couldn't reply u. any way i could write the code fr him in assembly, he translated to C its working fine. here is the code fr ur comments. i hv also attached the schematic.
thanks
sks
;A subroutine that continuously scans the keypad and returns the hex key
;pressed in the Accumulator & displays the hex value in port2
;my keys are like row0--0--1--2--3
;row0--0--1--2--3
;row1--4--5--6--7
;row2--8--9--A--B
;row3--C--D--E--F
org 0000h
main:
call kscan
mov p2,a
sjmp main

kscan:
call rowrd
jc kscan
call colrd
call convert
ret
rowrd:
clr c
mov p1,#0fh
mov r0,#0
jnb p1.0,gobk1
mov r0,#1
jnb p1.1,gobk1
mov r0,#2
jnb p1.2,gobk1
mov r0,#3
jnb p1.3,gobk1
setb c
gobk1:
ret
colrd:
mov p1,#0f0h
mov r1,#0
jnb p1.4,gobk2
mov r1,#1
jnb p1.5,gobk2
mov r1,#2
jnb p1.6,gobk2
mov r1,#3
jnb p1.7,gobk2
jmp colrd
gobk2:
ret
;Here i hv multiply the row no by 4 and added the column no
convert:
mov b,#4
mov a,r0
mul ab
add a,r1
ret