Discussion in "Project Help" started by    navintiwari08    Apr 12, 2012.
Thu Apr 12 2012, 07:10 PM
#1
hello everyone..
am having problem in writing and reading data from serial eeprom 24c02 interfaced with 8051(P89V51RD2).. please have a look at my program and help me out..
thanks a bunch:)

;-------------------------------------------
; using atmel 24c02 serial eeprom with 8051
;-------------------------------------------
sda equ p2.0
scl equ p2.1

org 00h
sjmp main

org 30h
main:

lcall eeprom_write
lcall eeprom_read
here:
sjmp here


eeprom_start:
setb sda
setb scl
lcall delay
clr sda
lcall delay
clr scl
ret

eeprom_stop:
clr sda
setb scl
lcall delay
setb sda
lcall delay
clr scl
ret

eeprom_write:
lcall eeprom_start
mov a,#0a0h ;device address with write bit
lcall send_data
mov a,#00h ;memory address on device to write to
lcall send_data
mov a,#25h ;data to write on the eeprom
lcall send_data
lcall eeprom_stop
ret

eeprom_read:
lcall eeprom_start
mov a,#0a0h ;device address with write bit(to perform dummy write)
lcall send_data
mov a,#00h ;memory address on device to set the address pointer
lcall send_data
lcall eeprom_start ;repeated start
mov a,#0a1h ;device address with read bit
lcall send_data
lcall get_data ;start reading
lcall eeprom_stop
ret

send_data:
mov r0,#08
loop: clr scl
lcall delay
rlc a
mov sda,c
lcall delay
setb scl
lcall delay
clr scl
djnz r0,loop
setb sda
ack: jb sda,ack ;polling the acknowledge by the device
setb scl
lcall delay
clr scl
ret

get_data:
mov r0,#08
setb sda
nop
loop1:
mov c,sda
setb scl
nop
nop
clr scl
rlc a
djnz r0,loop1
mov p0,a
ret

delay: mov r1,#10
rep: djnz r1,rep
ret

end


[ Edited Thu Apr 12 2012, 07:18 PM ]
Sat Apr 14 2012, 03:01 AM
#2
you have to put delay of atleast 5 to 10 ms after eeprom write to complete the write cycle. I am assuming your I2C is working fine.
Sat Apr 14 2012, 08:28 AM
#3
hello Ajay.. thanx for the reply.. i tried giving it the delay u proposed but it is still not working.. is my program correct? i checked many times but cant spot the error.. pls help. thanks..
Sun Apr 15 2012, 04:43 AM
#4
I dont see any problem the way you are reading from EEPROM but as I said, I am assuming your I2C driver is correct and working fine. You can take i2c reference from tutorial section. and see if everything is alright.
Sun Apr 15 2012, 08:23 AM
#5
thanks a lot Ajay, for the help.. i just solved it.. the 24c02a IC was damaged. i think i burnt it up.. i got a new 24c02 and its working perfectly.. thanks for caring to reply.. have a great day:)
Mon Apr 16 2012, 06:21 PM
#6
thats a good news. keep up the good work. Good Luck!

Get Social

Information

Powered by e107 Forum System

Conversation

Thu Jan 29 2015, 11:24 AM
durai
I found discussion relevant to my problem (link:http://www.8051projects.net/t59199/gsm-cdma-discussion/flashing-new-firmware-in-sim900-modem.htm) but i could not find the project mentioned in that discusion
Thu Jan 29 2015, 11:21 AM
durai
Hi i am using a SIM/900A GSM modem, I want to send email with an attachement using a microcontroller but when i try to use AT_Email commands it gives me error,I think modem doesnot support those commands,is there any other way to send mail using that modem??
ajay_bhargav
Thu Jan 29 2015, 06:54 AM
@gaurav, please mail me message you're trying to post.
ExperimenterUK
Thu Jan 29 2015, 01:17 AM
bhagyesh.bhavasar/gaurav.k I can post with Firefox. Can you try other browsers ?
naqirizvi
Wed Jan 28 2015, 08:08 AM
the web theme is too much buggy and heavy , admin please change it to simple theme, so that user can browse quickly
naqirizvi
Wed Jan 28 2015, 08:07 AM
some one please share software name or ebooks related to avr
bhagyesh.bhavasar
Tue Jan 27 2015, 11:06 AM
i want to share my project but there is problem occurred during postng
bhagyesh.bhavasar
Tue Jan 27 2015, 05:58 AM
@ExperimentalUK i have used that purple button but same as previous it takes me to blank page
ExperimenterUK
Sun Jan 25 2015, 08:10 PM
This box is for chat. Post problems in a suitable forum
ExperimenterUK
Sun Jan 25 2015, 08:04 PM
@gaurav.k Use the purple "Post reply" button. Green buttons often present a fresh edit box.

Downloads

Comments

sachinmm
Thu Jan 29 2015, 07:09 AM
nawfel
Sat Jan 17 2015, 07:27 AM
Rohi123
Sat Jan 10 2015, 11:00 AM
safakarici
Fri Jan 09 2015, 08:55 PM
Nikita_Pinjare
Thu Jan 08 2015, 03:10 PM
mayank058
Wed Jan 07 2015, 05:43 AM
Overeating
Tue Jan 06 2015, 05:56 AM
trancebreaker11
Sun Jan 04 2015, 07:42 AM

Online

Guests: 39, Members: 1 ...
ExperimenterUK viewing forum.php

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 37574
Newest member: sachinmm
Forum Activity
ExperimenterUK Avatar
Posted By ExperimenterUK
Thu Jan 29 2015, 06:45 PM
@naqirizviAs you already have a thread running I t...
naqirizvi Avatar
Posted By naqirizvi
Thu Jan 29 2015, 02:11 PM
Circuit diagram i am following i am not sure is it...
naqirizvi Avatar
Posted By naqirizvi
Thu Jan 29 2015, 02:11 PM
Circuit diagram i am following i am not sure is it...
naqirizvi Avatar
Posted By naqirizvi
Thu Jan 29 2015, 02:11 PM
Circuit diagram i am following i am not sure is it...
naqirizvi Avatar
Posted By naqirizvi
Thu Jan 29 2015, 01:50 PM
Hi,I am new to programming got some issues in RFID...
sachinmm Avatar
Posted By sachinmm
Thu Jan 29 2015, 07:21 AM
hello sir, plz tell me the circuit diagram interfa...
ajay_bhargav Avatar
Posted By ajay_bhargav
Thu Jan 29 2015, 06:28 AM
Moreover I see the segment Anode is connected via ...
ajay_bhargav Avatar
Posted By ajay_bhargav
Thu Jan 29 2015, 06:20 AM
LCD tutorial is written for 8051, you need to chan...
ajay_bhargav Avatar
Posted By ajay_bhargav
Thu Jan 29 2015, 06:17 AM
did you try any data sharing websites like 4shared...
ajay_bhargav Avatar
Posted By ajay_bhargav
Thu Jan 29 2015, 06:16 AM
you need to vary your PWM from 0 to 100 and then 100 to 0... it will generate sinewave.