Led matrix project using shift register and pic16f628a micro

This is aproject to move words on led matrix display
we use
1-pic16f628a as microcontroller :cheap,program memory 2k,has internal oscillatror,two ports A,B and alot of things.
2-led matrix 8*8  rows common anode and columns common cathode
3-shift register i use 74ls164 it is simple than 74595 his job is scanning columns activate one at atime
4-uln 2803
every time maximum of eight led work so current=8*(15ma for every led=120ma
shift register can't sink this much current so we use uln .it can sink current up to 500ma
5-eight resistors 120ohm,pack resistors 10k
The Complete Circuit diagram is Shown
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Step 1: Led matrix construction

ledmatrix is shown in pictures
to light aspecfic led we apply logic high(1) to anode and logic zero to cathode
so we make anode as data source and cathode as scanning (activate cathode of aspecfic column) so we connect anodes(rows) to portb and cathodes to uln and shift register
we discuss this later
dulari1 year ago
hllo.. cn i get data sheet for 8x8 led dot matrix?
cn u gv link fr dat?
we r prform same dis project at our university
alzrc_13j3 years ago
hi sir gudevening...im also planning to make a 8x8 led matrix......but im using PIC16f877A and micro c for my program...somehow i got the scanning for the columns but i dont know how to make my image appear fixed.....i, using proteus also to simulate the program and my clock is 4mhz...i tried to make my code run in a 8mhz clock but the program is still the same..i used 10us sec for the delay but its still the same...hope you could help me
mansman (author)  alzrc_13j3 years ago
Hi
You don't want to move the words isn't it you want to display words only and not move