Write n Read 24C04

Hello Mr Ajay,
Good evening.
You had asked in the last post
" 1. Are you getting character displayed properly? "
" 2. Are they scrolling the way you want (discard the speed or smoothness as its simulation)? "
Sorry to say both the answers are NO.
I had tested the code on my hardware today, the Chars/Texts are not properly showing, its some kind of garbage and the movement is from right to left.
But in my static char code it shows proper Chars/texts. I don't know why it is so. The static display code is same as the Scrolling code just without the 2 loops.
How could you guess just those 2 faults?
Please give some clues.
Thanks
with best regards
sks

I am going though your main loop and trying to understand how display works... but for you I have a suggestion.
As you have mentioned that your display part is working fine if you are using static display. try to move your display in open loop first just to get a clear idea. not much but 2-3 segment shifts. so all the tie time its gonna be a static display but everytime starting with a shift.

Sequence is (assuming you read eeprom and display ram is updated):

A. Normal static display for some time
B. Normal static display starting from next display location (Ram location: 50H + second col start)
C. Normal static display starting from 50H + third col start

if you are able to display this way.. (We call it open looping, e.g. for loop is opened and task is done n times) then surely something is wrong with display loop that scrolls. or you have not written it correct way. I am not sure if am able to make you understand what I am trying to say

Dear Mr Ajay,
Thanks for the reply and the advice. To night, i could see the text but the movement is in wrong direction and the LEDs are on where there is no texts. Ok i will try to correct that.
I don't know why you are not sure to make me understand? i am here for last 3 years and learning. what ever i have learnt, learnt from you like people.
Of course i am not capable to learn or understand things very easily.
I will try to modify the code as per your advice and let you know. Can you please tell me about Circular/Ring buffer or how can i shift data in my Ram?
Thanks
With best regards
sks

Dear Mr Ajay,
Thanks for giving some clue by writing in your last reply. You had written:
"if you are able to display this way.. (We call it open looping, e.g. for loop is opened and task is done n times) then surely something is wrong with display loop that scrolls. or you have not written it correct way"

I rewrite the display routine as advised by you, the chars moved 10 columns from left to right after repeating the display sub-routine 10 times, the only modification is incrementing 1 in each display ram address.
So my display loop is wrong some where. I don't know what to do now?
Thanks
with best regards
sks

you do not have to shift data in Ram all you need to do is shit the read pointer e.g. you 50 has the 5 bytes of first character and so on... now when scrolling one column at a time for next frame you need to read from location 55 which will have the next column data. and you need to put a check during ram read if incase you have reached the end of ram location read from 50 again and read till no of columns...

Thank you for appreciation

Thanks Mr Ajay for helping me.
Sorry i couldn't follow you completely. If possible please clarify little.

A: " you do not have to shift data in Ram all you need to do is shit the read pointer"
I understand this.

B: " you 50 has the 5 bytes of first character and so on.. "
I don't understand this. Are you saying, i should read for 1st char from 1st display ram address 50H to 55H (5 bytes) then increase address pointer by 6D?
Little confusion, let me try.

C: " you need to put a check during ram read if incase you have reached the end of ram location read from 50 again and read till no of columns... "
I do understand this.

Thanks
With best Regards
sks

For point B. i made little typo... I meant your display data starts from 50H. and each column uses 5 bytes (5x7 char). so during first iteration start reading from 50H, second iteration 51H third iteration 52H and so on.. your text will scroll shifting one column at a time. I hope i am clear this time no more confusion?

Thanks Mr Ajay.
No confusion now, its very clear.
Thanks
sks

Dear Mr Ajay,
Thanks for the helps and guidance from you and from all of your team members. I just competed the code and could see the texts are scrolling in right direction. Thanks all of you. I couldn't have completed without you and with out this forum.
Little bit modification has to be made in my code, like managing RAM area. My display hardware is completely assembled only the CPU part to be assembled. I was testing my code in my 8051 development kit.
I will test the code in real hardware in few days and post the result.
Thanks all
with best regards
sks

Great news SKS keep up the good work. I will wait for the final stuff with video