need help for data shifting control in 8x8 dot matrix display

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sureshkanna

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Hi dear friend...
* i am using PIC16f877A MC and
* 74HC595 for shifting ...
* 12MHz crystal frequency
* now i am giving 1 ms time delay

i wanna to scroll left to right on dot matrix display(13 characters). Actually it shifting well , but i cann't control the data shifting ... if i increased delay means it shifting character very slow, we cannt view.. also i gave less time delay,but it shifting very fast. i don't known correct time delay ... so pls give suggest for this problem dear friends....


left to right shifting logic
/***********************************************************/
void Green_disp_fh(void)
{
DS=0;
SHCP=0;
SHCP=1;
delay_ms(1);
STCP=1;
STCP=0;
for(i=0;i<70;i++)
{
PORTB=fh[k];
k++;
if(k==69)
{
k=0;
}
DS=1;
SHCP=0;
SHCP=1;
delay_ms(1);
STCP=1;
STCP=0;
}
}
/***********************************************************/
 

Seems it's a part of a column-scanning system but I see some problems.
If you are working in Proteus and using MikroC then attach here the complete project (DSN and all sources in a ZIP), only then can we help you.
 

ok fine dear friend ... herewith i add rar file. it contain full code , Proteus design ,photo of my hardware .... try to resolve my problem friends ....


my problem is
* i wanna to shift left to right without flickering and also
* to control data control flow . if i increase character means what i should change .



i am expecting for your valuable replay friends.
 

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    jito79

    Points: 2
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Hi sureshkanna;
Thanks for the attachment. Just as I thought, it really is a column-scan system.

I never use this method due to its brightness problems, but many people use it, they can quickly help you.
Later, if I have more time, I'll also try to fix your code, but in the meantime:

Here are a thread, where you can find many well working MMD projects. For example look at my posts (#671 to #689):
https://www.edaboard.com/posts/1125963/#post1125963
True, it uses the row-scan method ...
 

hi friend .... in row side i am connecting ULN2981 ,so i think it enough that brightness ,but still also i feeling difficult, to control data flow ...also what is refresh rate ? how to calculate this .... i am expecting valuable reply
 

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