Write fails but Read successful in EEPROM using I2C protocol

Please take a look at this link pastebin.com/fzV9R6hzfor my complete project code.
no, thank you, I have no intention of connecting to some obscure website and get flooded with emails/pick up a virus/...

This site does have a facility for posting code here.

my complete project
I doubt many hav e the trime to go through your "complete project", reduce the code to just the EEPROM code and post. BTW such a reductionm may, indeed, lead you to find the cause yourself.

Erik

Hello Erik this forum just doesn't allow more than 7000 characters and moreover pastebin.com link is just text copy/paste ..I am not asking anyone to download any file from that site ....no way ..I have pasted the code on that site and the link refers to the code I have pasted ...Oh God how should I convince someone that it isn't sinister ...ok atleast please refer this link for some convincing factor..

A pastebin is a type of web application that allows its users to upload snippets of text, usually samples of source code, for public viewing. It is very popular in IRC channels where pasting large amounts of text is considered bad etiquette. A new trend is that users use Pastebin to post Twitter messages that contain more than a 140 chars. A vast number of pastebins exist on the Internet, suiting a number of different needs and providing features tailored towards the crowd they focus on most.

from -- en.wikipedia.org/.../Pastebin

thanks and regards

Hello Erik this forum just doesn't allow more than 7000 characters

if you need more than that, to show your EEPROM code, that is why your code fails.

on the other hand, if you expect someone to filter out the EEPROM code from some huge mass of code, good luck.

A pastebin is a type of web application probably supported by selling the list of users.

Erik

Hello Erik I don't think you got the point regarding my code and pastebin.com..

First- Pastebin doesn't require any kind of registration ..just copy and paste and then distribute the link ...other options include - support for formatting in almost 20 languages C,C++,Javak,perl ...even shell..... etc...

Second: please think about my project modules ..I have created libraries myself and I intend to use it in a more modular way ...this way one can understand the modules better and no one would appreciate cramping the whole logic in one C file... and 7000+ Chars well that could evem mean the blank spaces ...tabs etc...and of course the comment beginning for the post as well....

There are altogether 5 files ...
1) .c file containing main()
2) AT24C04-I2C.H & AT24C04-I2C.c --> these are for the I2C routines handling
3) AT24C04-EEPROM.h & AT24C04-EEPROM.c -->these are for the EEPROM routines
4) AT24C04-LCD.h & AT24C04-LCD.c --> these are for LCD handling.

So I would request you to take a look ...and infact I explained where the problem rises ...may be along with the comments in the code you can find that one deceptive error and help me....

thanks and regards

I doubt many hav e the trime to go through your "complete project", reduce the code to just the EEPROM code and post. BTW such a reductionm may, indeed, lead you to find the cause yourself.

OK Erik ...I have almost posted to a dozen forum and I can't find anyone able for this issue because its strange ...I wouldn't had asked you to look into this since if it hadn't been so deceptive I would have just ignored ...but everyone here just can't believe it and have been pondering ..it isn't any logical spaghetti but plain logic ...almost all debugging has been done and timing diagrams,circuit debugging ...almost everything is done ....

I use the same I2C library funcions defined in AT24C04-I2C.c file and the 2 functions are EERPOM_read() and EEPROM_write();

These 2 functions call the same functions from AT24C04-I2C.c file ....whats strange is that EEPROM_write() writes DEVICE ADDRESS,EEPROM REGISTER ADDRESS & USERDATA...

on the the other hand EEPROM_read() writes DEVICE ADDRESS,EEPROM REGISTER ADDRESS & USERDATA... followed by RESTART and then receives the data from EEPROM ..

So no doubt both the EEPROM_read() and EEPROM_write functions call the same I2C related function its only the EEPROM_read() which is succeeding

THIS IS STRANGE AS ITS TANTAMOUNT TO SAYING THE EEPROM_read() is ACTUALLY WRITING FIRST THE DEVICE ADDRESS,EEPROM ADDRESS.....THIS IS A MUST TO FETCH THE USER DATA... and EEPROM_write() whereas does the same thing but just can't write !!!!!!

on a read you write ONE byte, on a write, you write more than one byte. have a look.

if you use a chip such as SILabs or HAVE an ICE, debugging this should be a breeze.

try the code on a SILabs devboard if you do not have an ICE

good tools are half the job, thus buy two sets :)

Erik

So, you have activated people on a dozen forums, without telling people that they are doing the same thing lots of other peoples are also doing.

Cross-posting in itself isn't bad. Cross-posting without adding links to all forums are really not nice.

Hello Erik well I am working on a custom designed kit and the MC is P89V61RD2BN - 8051 from Philips...so no ICE :( ..and moreover I have finished debugging again - I have put a break point at the if condition i.e if( ! SDA ){} ...just to check the timimg on the simulator of KEIL V4 ...everything seems OKAY but again to REPEAT EEPROM_write() is doing the same as EEPROM_read() and checking of ACK is also done and i get the expected results for each of ACK(s) but EEPROM_read() still succeeds and EEPROM_write() fails !!!!

If you can take a look the way I am handling logic for ACK and if you can give your feedback ..then it would be great....If you get some time ...please let me know thanks

Hello Per Westerrek ...yes I indeed involved other people and they too have beemn pondering about what might have gone wrong ..because they too can't figure out ...this STRANGE error of mine and moreover I have coded it all by myself and now I am trying to get it worked for the past 8 days or so ..hope you can understand the frustration.. I am trying to get max help from all ..but still nothing :( ..heres one post ..

www.edaboard.com/thread232357.html

thanks

the MC is P89V61RD2BN - 8051 from Philips
could not find a datasheet

If you can take a look the way I am handling logic for ACK and if you can give your feedback

as said before: the people that pay me for my time would be upset if I spent the time needed to scour through a "project".

EXTRACT FROM YOUR CODE A SIMPLE PROGRAM THAT WRITES AND READ FROM EEPROM NOTHING ELSE

Erik

I indeed involved other people and they too have beemn pondering about what might have gone wrong ..because they too can't figure out
or maybe did not have the time to extract the significant parts from a "project".

I am trying to get it worked for the past 8 days or so
if you, day one, had extracted the EEPROM code into a simple program and published it, you would have been up and running a week ago. Your unwillingness to help those that may be willing to help you only hurts you

btw you keep saying there is no difference between the write before read and a write there is a difference: if your code can wirie one byte, but not multiple bytes, read will work, write will not

Erik