[SOLVED] DOT matrix flickering problem/incomplete character

[Umer Hassan]

Hello, I am new to PIC UC and i am in learning phase. well i am getting problem in simulating Dot matrix that when i display only static 6 characters on the 6 8x8 dot matrix. they look perfectly fine. but when i increase the dot matrix, let say 8 8x8 dotmatrix the characters dont display properly and flickering occurs. also i need help to improve my code. Right now i have not used

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#define data_line PORTB
#define address_line PORTC
#define digit PORTD
#define en1 PORTD.B0
#define en2 PORTD.B1
#define en3 PORTD.B2
#define en4 PORTD.B3
#define en5 PORTD.B4
#define en6 PORTD.B5
#define en7 PORTD.B6
#define en8 PORTD.B7
#define segdel 500
 
 
unsigned char i,acol, afont[10][8] = {
        0x18, 0x24, 0x24, 0x24, 0x24, 0x24, 0x18, 0x00,
        0x08, 0x18, 0x08, 0x08, 0x08, 0x08, 0x1C, 0x00,
        0x18, 0x24, 0x04, 0x1C, 0x20, 0x20, 0x3C, 0x00,
        0x18, 0x24, 0x04, 0x18, 0x04, 0x24, 0x18, 0x00,
        0x24, 0x24, 0x24, 0x3C, 0x04, 0x04, 0x04, 0x00,
        0x3C, 0x20, 0x38, 0x04, 0x04, 0x24, 0x18, 0x00,
        0x18, 0x20, 0x38, 0x24, 0x24, 0x24, 0x18, 0x00,
        0x3C, 0x04, 0x04, 0x08, 0x10, 0x10, 0x10, 0x00,
        0x18, 0x24, 0x24, 0x18, 0x24, 0x24, 0x18, 0x00,
        0x18, 0x24, 0x24, 0x1C, 0x04, 0x04, 0x18, 0x00
        };
 
unsigned int count;
void main()
{
TRISB=TRISC=TRISD=0x00;
PORTB=0x00;
en1=en2=en3=en4=en5=en6=en7=en8=0;
while(1)
{
for(acol=0;acol<8;acol++)
{
en8=0;
en1=1;
data_line = 0x00;
data_line = afont[0][acol];
address_line = acol;
delay_us(segdel);
en1=0;
en2=1;
data_line = 0x00;
data_line = afont[1][acol];
address_line = acol;
delay_us(segdel);
en2=0;
en3=1;
data_line = 0x00;
data_line = afont[2][acol];
address_line = acol;
delay_us(segdel);
en3=0;
en4=1;
data_line = 0x00;
data_line = afont[3][acol];
address_line = acol;
delay_us(segdel);
en4=0;
en5=1;
data_line = 0x00;
data_line = afont[4][acol];
address_line = acol;
delay_us(segdel);
en5=0;
en6=1;
data_line = 0x00;
data_line = afont[5][acol];
address_line = acol;
delay_us(segdel);
en6=0;
en7=1;
data_line = 0x00;
data_line = afont[6][acol];
address_line = acol;
delay_us(segdel);
en7=0;
en8=1;
data_line = 0x00;
data_line = afont[7][acol];
address_line = acol;
delay_us(segdel);
}
}
}

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[FvM]

Don't know what the "segment delay" value actually is, but there should be no problem to run the code in real hardware without flicker.

In case you are talking about flickering in the proteus simulation, I suspect a pure simulation problem. Adjust the timeout in the LED display properties.

 

[Umer Hassan]

segment delay is just a constant value for delay_us(). Well thanks bro i just adjusted the Led Trigger time and it works well.