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karthickiw
Joined: 09 Aug 2007
Posts: 82
Location: TN, India
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| Problem with LED dot matrix display |
 Posted: Sun Mar 29, 2009 7:12 am |
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Hi friends,
I write the program to display the “Hello” in scrolling 7X60 LED display. I successful to scrolling the “Hello” massage in 7X60 LED display. I have problem with brightness of LED display  . I don’t put any resistor for LED display. My coding is below….
| Code: |
#include<16f876.h>
#use delay(clock=20M)
#fuses NOWDT,HS, PUT, PROTECT, NODEBUG, BROWNOUT, NOLVP, CPD, WRT
#byte port_b=6
#define EXP_OUT_ENABLE PIN_A2 //RCK
#define EXP_OUT_CLOCK PIN_A1 //SCK
#define EXP_OUT_DO PIN_A0 //SER
#define NUMBER_OF_74595 7
#include <74595.C>
int inc=0,chr_no=31,column_no=56,last_inc; // chr_no calculate from zero//
long int time2=0;
int CONST str_MAP[]={0x00 , 0x00 , 0x00 , 0x00 , 0x00,
0x7F , 0x08 , 0x08 , 0x08 , 0x7F,
0x00 , 0x38 , 0x54 , 0x54 , 0x54,
0x48 , 0x00 , 0x7F , 0x00 ,
0x00 , 0x7F , 0x00 ,
0x38 , 0x44 , 0x44 , 0x44 , 0x38,
0x00 , 0x00 , 0x00 , 0x00 , 0x00};
#INT_timer2 // move the character in display
void seconds_timer2()
{
time2++;
if(time2==100)
{
inc++;
if (inc==(chr_no+1)) inc=0;
time2=0;
}
}
void main() {
int data[7]=0XFF,0XFF,0XFF,0XFF,0XFF,0XFF,0X7F;
int mask[7]; //ffef
int Column=0,str=0,act=0;
setup_timer_2(T2_DIV_BY_16,255,1);
enable_interrupts(INT_TIMER2);
enable_interrupts(GLOBAL);
//disable_interrupts(INT_TIMER2);
set_tris_b (0x00);
str=chr_no;
column=column_no;
while (TRUE)
{
IF (str==255)
{
str=chr_no;
}
mask[0]=data[0]; // move the data into the mask temp space
mask[1]=data[1];
mask[2]=data[2];
mask[3]=data[3];
mask[4]=data[4];
mask[5]=data[5];
mask[6]=data[6];
// port_b=0x00;
write_expanded_outputs (data); // sent the data to 74HC595
act=str+inc;
if (act >chr_no) act=act-(chr_no+1); // rotate the string
port_b= str_map[act]; // sent the string to port B
data[0]=mask[0]; // move the temp data into the data
data[1]=mask[1];
data[2]=mask[2];
data[3]=mask[3];
data[4]=mask[4];
data[5]=mask[5];
data[6]=mask[6];
str--; // increase the string pointer
if(Column==1) // check colume is end or not
{
data[0]=0XFF; // referene from frist column
data[1]=0XFF;
data[2]=0XFF;
data[3]=0XFF;
data[4]=0XFF;
data[5]=0XFF;
data[6]=0X7F;
Column=column_no;
str=chr_no;
}
else
{
Column--;
if ( column <= 8)
{
if (column==8)
{
data[0]=0X7F;
data[1]=0XFF;
data[2]=0XFF;
data[3]=0XFF;
data[4]=0XFF;
data[5]=0XFF;
data[6]=0XFF;
}
else
{
rotate_right( &data[0] , 1); //move the next column L <---- R
}
}
else if( column<=16)
{
if (column==16)
{
data[0]=0XFF;
data[1]=0X7F;
data[2]=0XFF;
data[3]=0XFF;
data[4]=0XFF;
data[5]=0XFF;
data[6]=0XFF;
}
else
{
rotate_right( &data[1] , 1); //move the next column L <---- R
}
//rotate_right( &data[1] , 1);
}
else if( column<=24)
{
if (column==24)
{
data[0]=0XFF;
data[1]=0XFF;
data[2]=0X7F;
data[3]=0XFF;
data[4]=0XFF;
data[5]=0XFF;
data[6]=0XFF;
}
else
{
rotate_right( &data[2] , 1); //move the next column L <---- R
}
}
else if( column<=32)
{
if (column==32)
{
data[0]=0XFF;
data[1]=0XFF;
data[2]=0XFF;
data[3]=0X7F;
data[4]=0XFF;
data[5]=0XFF;
data[6]=0XFF;
}
else
{
rotate_right( &data[3] , 1); //move the next column L <---- R
}
}
else if( column<=40)
{
if (column==40)
{
data[0]=0XFF;
data[1]=0XFF;
data[2]=0XfF;
data[3]=0XFF;
data[4]=0X7F;
data[5]=0XFF;
data[6]=0XFF;
}
else
{
rotate_right( &data[4] , 1); //move the next column L <---- R
}
}
else if( column<=48)
{
if (column==48)
{
data[0]=0XFF;
data[1]=0XFF;
data[2]=0XfF;
data[3]=0XFF;
data[4]=0XFF;
data[5]=0X7F;
data[6]=0XFF;
}
else
{
rotate_right( &data[5] , 1); //move the next column L <---- R
}
}
else if( column<=56)
{
if (column==56)
{
data[0]=0XFF;
data[1]=0XFF;
data[2]=0XfF;
data[3]=0XFF;
data[4]=0XFF;
data[5]=0XFF;
data[6]=0X7F;
}
else
{
rotate_right( &data[6] , 1); //move the next column L <---- R
}
}
}
//delay_us(500);
}// while
}// main |
Give the idea to increase the brightness of the LED display… |
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asmboy
Joined: 20 Nov 2007
Posts: 2128
Location: albany ny
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| Posted: Sun Mar 29, 2009 7:55 am |
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without knowing the schematic you have for the HARDWARE - posting all the code in the world won't get an answer. perhaps if you post the same question 5 more times - .............
yours is not a problem of CODE - but of lack of electronics understanding - it appears THAT problem is very common here and has no easy answer . |
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rote
Guest
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| Do you have a schematic? |
| Posted: Mon Apr 20, 2009 10:25 pm |
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I am interested in this project. I look at code and test is working but I
don't know your circuits.
Please post schematic of this project.
Thank you. |
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OE8PCK
Joined: 19 Apr 2009
Posts: 14
Location: Klagenfurt, AUSTRIA
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| Posted: Tue Apr 21, 2009 6:03 am |
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I would suggest driving the leds through transistors, this way you can adjust the brightness with resistors. Driving directly on this scale does not seem to be a good idea. 
Paul OE8PCK |
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karthickiw
Joined: 09 Aug 2007
Posts: 82
Location: TN, India
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| Re: Do you have a schematic? |
| Posted: Fri May 22, 2009 11:21 pm |
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| rote wrote: | I am interested in this project. I look at code and test is working but I
don't know your circuits.
Please post schematic of this project.
Thank you. |
Give me your email id, I send schematic. |
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