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LED DOT Matrix with 16f876a

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care fully Look the data sheet of both IC .. i think same

You refer here may be helpful
thanks

Set MR=1
Set OE=0
Set STCP=0
Set SHCP=0

Give to DS the value of D7
toggle SHCP (to 1 and back to 0)
Give to DS the value of D6
toggle SHCP (to 1 and back to 0)
....
Give to DS the value of D0
toggle SHCP (to 1 and back to 0)
toggle STCP (to 1 and back to 0) to see the data in the output

SHCP shifts the data without changing the output state, when you are done shifting you toggle STCP to output the result

https://www.edaboard.com/threads/228008/

Look out the threads
 

Hello there,I got another link which helps more deeply,can you please help me to replace 74LS138 by CD4515.

I can't find those 74LS138 but the CD4515 i have them;see the link **broken link removed** on Serial Matrix topic for scrolling text.µ

Thanks.

Thanks.
 

Hello here is my project I am using PIC16F876A and 3 LED DOT MATRIX for displaying the letters "GSP" but the text is not scrolling very well;with the physical implementation on the project board the circuit is not working what I get is only some diodes which are making fluctuations but nothing displayed as a letter nor a symbol.

The problem I am not able to attach the file of schematics not inserting an image here.

Please help.
 
Last edited:

Hello who can help me to insert a Driver in this circuit of Scrolling text message.In proteus with simulation it works without the ULN2803 but when I put it the simualtiona also goes wrong,on the board when I don't put the ULN2803 no any led lighting but by adding a ULN2803 I get the same thing with simulation(with simulation I have wrong output)
.

NB:How can I proceed for attaching this document when use Reply button on post?I can't attacg but the orginal file is located on **broken link removed**SerialMatrix_Full.Zip;I replaced the PIC16F876A with PIC16F84A.

The pinout of LED DOT MATRIX I used are located on this site:https://circuitdesolator.blogspot.com/2010/12/led-dot-matrix-pin-configuration.html

Thanks.
 

IC ULN2803 invert input, So to use ULN2803 you need invert bits before set to PIN of MCU and You need used correct port to control LED.
 
Last edited:

how may I define those ports?
 

This schematic used PORT B and PORT C.
In code:
Code:
[B]TRISB [/B]= 0b00000000; // Set [B]PORTB[/B] direction to be output
[B]TRISC [/B]= 0x00; // Set [B]PORTC [/B]direction to be output
[B]PORTB [/B]= 0x00; // Turn OFF LEDs on [B]PORTB[/B]
...
        [B]PORTB [/B]= characters[count]; // [B]PORT B[/B]
        [B]PORTC [/B]= column; //[B] PORT C[/B]

View attachment 95135

See the image above.Consider if there is any other modification,please help.!!
 

I dit it but nothing going well, I even changed by adding a NOT gate but no proper result found.

Please help.
 

Could you try run without ULN2803 and with one LED matrix?
 

When I run the circuit without ULN2803 the LED DOT MATRIX are not displaying.
 

Could you post your code and schematic without ULN2803?
 

Zip and post the original mikroC code and its Proteus file which is working and mention what replacement you want. Also post the new Proteus Circuit.
 

Hello Sir,here is the circuit which works using 74LS164 and without dot matrix (it only run in simulation on the baord it is)so I want to add a dot matrix driver and replace 74ls138 withCD4017 ;all circuits are here ;here below are other codes which uses 74LS595,cd4017 and ULN2803 if possible you can help me to edit those ones and replace the 74ls595 by 74ls164;sir you see how you can help me .

PHP:
/*
  Project: Scrolling message on LED dot matrix display
  MCU: PIC18F2550 @ 48.0 MHz (StartUSB for PIC board)
  Copyright @ Rajendra Bhatt
  May 16, 2011
*/

// Define LCD module connections.
/* sbit Serial_Data at LATC2_bit;
 sbit SH_Clk at LATC6_bit;
 sbit ST_Clk at LATC7_bit;
 sbit CD4017_Clk at LATA2_bit;
 sbit CD4017_RST at LATA1_bit;
  */
 sbit Serial_Data at RC2_bit;
 sbit SH_Clk at RC6_bit;
 sbit ST_Clk at RC7_bit;
 sbit CD4017_Clk at RA2_bit;
 sbit CD4017_RST at RA1_bit;

void send_data(unsigned int temp){
 unsigned int Mask = 0x0001, t, Flag;
  for (t=0; t<16; t++){
   Flag = temp & Mask;
   if(Flag==0) Serial_Data = 0;
   else Serial_Data = 1;
   SH_Clk = 1;
   SH_Clk = 0;
   Mask = Mask << 1;
  }
  // Apply clock on ST_Clk
  ST_Clk = 1;
  ST_Clk = 0;

}

/* CharData is a two dimensional constant array that holds the 8-bit column values of
   individual rows for ASCII characters that are to be displayed on a 8x8 matrix format.
*/
const unsigned short CharData[][8] ={
{0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000},
{0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000000, 0b00000100},
{0b00001010, 0b00001010, 0b00001010, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000},
{0b00000000, 0b00001010, 0b00011111, 0b00001010, 0b00011111, 0b00001010, 0b00011111, 0b00001010},
{0b00000111, 0b00001100, 0b00010100, 0b00001100, 0b00000110, 0b00000101, 0b00000110, 0b00011100},
{0b00011001, 0b00011010, 0b00000010, 0b00000100, 0b00000100, 0b00001000, 0b00001011, 0b00010011},
{0b00000110, 0b00001010, 0b00010010, 0b00010100, 0b00001001, 0b00010110, 0b00010110, 0b00001001},
{0b00000100, 0b00000100, 0b00000100, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000},
{0b00000010, 0b00000100, 0b00001000, 0b00001000, 0b00001000, 0b00001000, 0b00000100, 0b00000010},
{0b00001000, 0b00000100, 0b00000010, 0b00000010, 0b00000010, 0b00000010, 0b00000100, 0b00001000},
{0b00010101, 0b00001110, 0b00011111, 0b00001110, 0b00010101, 0b00000000, 0b00000000, 0b00000000},
{0b00000000, 0b00000000, 0b00000100, 0b00000100, 0b00011111, 0b00000100, 0b00000100, 0b00000000},
{0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000110, 0b00000100, 0b00001000},
{0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00001110, 0b00000000, 0b00000000, 0b00000000},
{0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000100},
{0b00000001, 0b00000010, 0b00000010, 0b00000100, 0b00000100, 0b00001000, 0b00001000, 0b00010000},
{0b00001110, 0b00010001, 0b00010011, 0b00010001, 0b00010101, 0b00010001, 0b00011001, 0b00001110},
{0b00000100, 0b00001100, 0b00010100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00011111},
{0b00001110, 0b00010001, 0b00010001, 0b00000010, 0b00000100, 0b00001000, 0b00010000, 0b00011111},
{0b00001110, 0b00010001, 0b00000001, 0b00001110, 0b00000001, 0b00000001, 0b00010001, 0b00001110},
{0b00010000, 0b00010000, 0b00010100, 0b00010100, 0b00011111, 0b00000100, 0b00000100, 0b00000100},
{0b00011111, 0b00010000, 0b00010000, 0b00011110, 0b00000001, 0b00000001, 0b00000001, 0b00011110},
{0b00000111, 0b00001000, 0b00010000, 0b00011110, 0b00010001, 0b00010001, 0b00010001, 0b00001110},
{0b00011111, 0b00000001, 0b00000001, 0b00000001, 0b00000010, 0b00000100, 0b00001000, 0b00010000},
{0b00001110, 0b00010001, 0b00010001, 0b00001110, 0b00010001, 0b00010001, 0b00010001, 0b00001110},
{0b00001110, 0b00010001, 0b00010001, 0b00001111, 0b00000001, 0b00000001, 0b00000001, 0b00000001},
{0b00000000, 0b00000100, 0b00000100, 0b00000000, 0b00000000, 0b00000100, 0b00000100, 0b00000000},
{0b00000000, 0b00000100, 0b00000100, 0b00000000, 0b00000000, 0b00000100, 0b00000100, 0b00001000},
{0b00000001, 0b00000010, 0b00000100, 0b00001000, 0b00001000, 0b00000100, 0b00000010, 0b00000001},
{0b00000000, 0b00000000, 0b00000000, 0b00011110, 0b00000000, 0b00011110, 0b00000000, 0b00000000},
{0b00010000, 0b00001000, 0b00000100, 0b00000010, 0b00000010, 0b00000100, 0b00001000, 0b00010000},
{0b00001110, 0b00010001, 0b00010001, 0b00000010, 0b00000100, 0b00000100, 0b00000000, 0b00000100},
{0b00001110, 0b00010001, 0b00010001, 0b00010101, 0b00010101, 0b00010001, 0b00010001, 0b00011110},
{0b00001110, 0b00010001, 0b00010001, 0b00010001, 0b00011111, 0b00010001, 0b00010001, 0b00010001},
{0b00011110, 0b00010001, 0b00010001, 0b00011110, 0b00010001, 0b00010001, 0b00010001, 0b00011110},
{0b00000111, 0b00001000, 0b00010000, 0b00010000, 0b00010000, 0b00010000, 0b00001000, 0b00000111},
{0b00011100, 0b00010010, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010010, 0b00011100},
{0b00011111, 0b00010000, 0b00010000, 0b00011110, 0b00010000, 0b00010000, 0b00010000, 0b00011111},
{0b00011111, 0b00010000, 0b00010000, 0b00011110, 0b00010000, 0b00010000, 0b00010000, 0b00010000},
{0b00001110, 0b00010001, 0b00010000, 0b00010000, 0b00010111, 0b00010001, 0b00010001, 0b00001110},
{0b00010001, 0b00010001, 0b00010001, 0b00011111, 0b00010001, 0b00010001, 0b00010001, 0b00010001},
{0b00011111, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00011111},
{0b00011111, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00010100, 0b00001000},
{0b00010001, 0b00010010, 0b00010100, 0b00011000, 0b00010100, 0b00010010, 0b00010001, 0b00010001},
{0b00010000, 0b00010000, 0b00010000, 0b00010000, 0b00010000, 0b00010000, 0b00010000, 0b00011111},
{0b00010001, 0b00011011, 0b00011111, 0b00010101, 0b00010001, 0b00010001, 0b00010001, 0b00010001},
{0b00010001, 0b00011001, 0b00011001, 0b00010101, 0b00010101, 0b00010011, 0b00010011, 0b00010001},
{0b00001110, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00001110},
{0b00011110, 0b00010001, 0b00010001, 0b00011110, 0b00010000, 0b00010000, 0b00010000, 0b00010000},
{0b00001110, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010101, 0b00010011, 0b00001111},
{0b00011110, 0b00010001, 0b00010001, 0b00011110, 0b00010100, 0b00010010, 0b00010001, 0b00010001},
{0b00001110, 0b00010001, 0b00010000, 0b00001000, 0b00000110, 0b00000001, 0b00010001, 0b00001110},
{0b00011111, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100},
{0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00001110},
{0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00001010, 0b00000100},
{0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010001, 0b00010101, 0b00010101, 0b00001010},
{0b00010001, 0b00010001, 0b00001010, 0b00000100, 0b00000100, 0b00001010, 0b00010001, 0b00010001},
{0b00010001, 0b00010001, 0b00001010, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100},
{0b00011111, 0b00000001, 0b00000010, 0b00000100, 0b00001000, 0b00010000, 0b00010000, 0b00011111},
{0b00001110, 0b00001000, 0b00001000, 0b00001000, 0b00001000, 0b00001000, 0b00001000, 0b00001110},
{0b00010000, 0b00001000, 0b00001000, 0b00000100, 0b00000100, 0b00000010, 0b00000010, 0b00000001},
{0b00001110, 0b00000010, 0b00000010, 0b00000010, 0b00000010, 0b00000010, 0b00000010, 0b00001110},
{0b00000100, 0b00001010, 0b00010001, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000},
{0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00011111},
{0b00001000, 0b00000100, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000},
{0b00000000, 0b00000000, 0b00000000, 0b00001110, 0b00010010, 0b00010010, 0b00010010, 0b00001111},
{0b00000000, 0b00010000, 0b00010000, 0b00010000, 0b00011100, 0b00010010, 0b00010010, 0b00011100},
{0b00000000, 0b00000000, 0b00000000, 0b00001110, 0b00010000, 0b00010000, 0b00010000, 0b00001110},
{0b00000000, 0b00000001, 0b00000001, 0b00000001, 0b00000111, 0b00001001, 0b00001001, 0b00000111},
{0b00000000, 0b00000000, 0b00000000, 0b00011100, 0b00010010, 0b00011110, 0b00010000, 0b00001110},
{0b00000000, 0b00000011, 0b00000100, 0b00000100, 0b00000110, 0b00000100, 0b00000100, 0b00000100},
{0b00000000, 0b00001110, 0b00001010, 0b00001010, 0b00001110, 0b00000010, 0b00000010, 0b00001100},
{0b00000000, 0b00010000, 0b00010000, 0b00010000, 0b00011100, 0b00010010, 0b00010010, 0b00010010},
{0b00000000, 0b00000000, 0b00000100, 0b00000000, 0b00000100, 0b00000100, 0b00000100, 0b00000100},
{0b00000000, 0b00000010, 0b00000000, 0b00000010, 0b00000010, 0b00000010, 0b00000010, 0b00001100},
{0b00000000, 0b00010000, 0b00010000, 0b00010100, 0b00011000, 0b00011000, 0b00010100, 0b00010000},
{0b00000000, 0b00010000, 0b00010000, 0b00010000, 0b00010000, 0b00010000, 0b00010000, 0b00001100},
{0b00000000, 0b00000000, 0b00000000, 0b00001010, 0b00010101, 0b00010001, 0b00010001, 0b00010001},
{0b00000000, 0b00000000, 0b00000000, 0b00010100, 0b00011010, 0b00010010, 0b00010010, 0b00010010},
{0b00000000, 0b00000000, 0b00000000, 0b00001100, 0b00010010, 0b00010010, 0b00010010, 0b00001100},
{0b00000000, 0b00011100, 0b00010010, 0b00010010, 0b00011100, 0b00010000, 0b00010000, 0b00010000},
{0b00000000, 0b00001110, 0b00010010, 0b00010010, 0b00001110, 0b00000010, 0b00000010, 0b00000001},
{0b00000000, 0b00000000, 0b00000000, 0b00001010, 0b00001100, 0b00001000, 0b00001000, 0b00001000},
{0b00000000, 0b00000000, 0b00001110, 0b00010000, 0b00001000, 0b00000100, 0b00000010, 0b00011110},
{0b00000000, 0b00010000, 0b00010000, 0b00011100, 0b00010000, 0b00010000, 0b00010000, 0b00001100},
{0b00000000, 0b00000000, 0b00000000, 0b00010010, 0b00010010, 0b00010010, 0b00010010, 0b00001100},
{0b00000000, 0b00000000, 0b00000000, 0b00010001, 0b00010001, 0b00010001, 0b00001010, 0b00000100},
{0b00000000, 0b00000000, 0b00000000, 0b00010001, 0b00010001, 0b00010001, 0b00010101, 0b00001010},
{0b00000000, 0b00000000, 0b00000000, 0b00010001, 0b00001010, 0b00000100, 0b00001010, 0b00010001},
{0b00000000, 0b00000000, 0b00010001, 0b00001010, 0b00000100, 0b00001000, 0b00001000, 0b00010000},
{0b00000000, 0b00000000, 0b00000000, 0b00011111, 0b00000010, 0b00000100, 0b00001000, 0b00011111},
{0b00000010, 0b00000100, 0b00000100, 0b00000100, 0b00001000, 0b00000100, 0b00000100, 0b00000010},
{0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100, 0b00000100},
{0b00001000, 0b00000100, 0b00000100, 0b00000100, 0b00000010, 0b00000100, 0b00000100, 0b00001000},
{0b00000000, 0b00000000, 0b00000000, 0b00001010, 0b00011110, 0b00010100, 0b00000000, 0b00000000}
};

unsigned int DisplayBuffer[]={0,0,0,0,0,0,0,0};
unsigned int speed;
short i, l, k, ShiftAmount, scroll, temp, shift_step=1, StringLength;
char message[]="SCROLLING MESSAGE ON LED DOT-MATRIX DISPLAY FROM WWW.EMBEDDED-LAB.COM ";
char index;
void main() {
 CMCON = 0x07;   // Disable comparators
 ADCON0 = 0x00; // Select ADC channel AN0
 ADCON1 = 0b00001110;  // RA0 as analog input
 TRISC = 0x00;
 TRISB = 0xFF;
 TRISA = 0x01;
 StringLength = strlen(message) ;
 do {
 for (k=0; k<StringLength; k++){
  for (scroll=0; scroll<(8/shift_step); scroll++) {
   for (ShiftAmount=0; ShiftAmount<8; ShiftAmount++){
    index = message[k];
    temp = CharData[index-32][ShiftAmount];
    DisplayBuffer[ShiftAmount] = (DisplayBuffer[ShiftAmount] << shift_step)| (temp >> ((8-shift_step)-scroll*shift_step));
   }

  speed = 10+ADC_Read(0)/10;
  for(l=0; l<speed;l++){

   for (i=0; i<8; i++) {

    send_data(DisplayBuffer[i]);
    CD4017_Clk = 1;
    CD4017_Clk = 0;
    Delay_ms(1);
   }  // i
  CD4017_Rst = 1;
  CD4017_Rst = 0;
  } // l
  } // scroll
 } // k

 } while(1);

} With those ones the circuits in use is 74HCT595

Thanks,please help..
 

Attachments

  • Proposed_Circuit.zip
    32.7 KB · Views: 84
  • Running codes_Circuit.zip
    62.8 KB · Views: 90

Experts are needed to solve the problem. I am attaching a file which is not fully working. If you replace NOT gates by UNL2803 then you should put pullups at the o/ps of ULN2803 to keep the pins high so that only one pin is made low each time.
 

Attachments

  • Proposed_Circuit.rar
    110.5 KB · Views: 87

I have to replace the ULN2803 or I have to add a NOT gate,I did this but it is not succeeding ,I know that the 74LS138 is active low while ULN2803 is active high but
when adding a NOT gate I saw the column scrolling nothing else,
Let me test the codes you posted here I let you know the o/p.

Thanks.
 

Hello jayanth.devarayanadurga the circuit is not working ,the codes you proposed are the ones for the same circuit?

Please let me know.
 

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