4*74hc595 for an animated display

Using Arduino LEDs and Multiplexing
1

Hi ,
i want to do a display with 84 leds so i used a 74hc595 with an arduino Uno. However , i don't know how to manage the four 74hc595 to light up the led one by one and make them all blink. For this implementation ,i do first a modelisation on Proteus . i learn how one 74hc595 function but when i use the four 74hc595 i don't know how to shiftOut 4bytes to create sequence of byte for lighting up my 84 led one by one and after make them all blind.
I already thanking you for your help

2

i don't know how to shiftOut 4bytes

Lots of ways. I don't know how you are doing it now.
You can split the output pattern into 4 bytes and use shift out four times. Or use the idea below and shift the output pattern 8 places to the right before each shift out. Do not latch the data between these four shift outs, only latch at the very start and very end.

To handle 4 shift registers you need a variable type that is 4 bytes lone. The long unsigned int is such a variable type.

3

Hi ,thank you for answering.In fact,to light up the leds one by one i have to shift out 4 bytes.I try to used a special shiftOut algorithm to transmit 4bytes simultaneously that i read in another topic on the 16th message that you can see on the link below:
http://forum.arduino.cc/index.php?topic=157756.msg1966948#msg1966948
But my program don't work i don't know why.I might have done a bad modification to use it for 4 registers 74hc595
Waiting your answer.

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4

There is nothing more useless than a screen dump of code, other than a Frtizing layout diagram.

Please post the code, and all the code, correctly.

Please read this:-
How to use this forum

5

sorry Here is my code:

const int verrou = 10;
//Broche connectée au SH_CP du 74HC595
const int horloge = 12;
//Broche connectée au DS du 74HC595
const int data = 11;
//The 4bytes i want to shift out 
uint32_t myData=0b11001111000010101111111111111111;
void setup()
{
    
    pinMode(verrou, OUTPUT);
    pinMode(horloge, OUTPUT);
    pinMode(data, OUTPUT);
}
 

void loop()
{
    for (int i = 0; i < 32; i++)
    {
       
        digitalWrite(verrou, LOW);
        shiftOut32(data, horloge, MSBFIRST,myData,32,100); 
       //myData=myData>>8;
          //myData =    myData | (0x00000001 << i);
    
        digitalWrite(verrou, HIGH);
        delay(500);
}
  
}

//This function might shift out 4bytes
void shiftOut32(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint32_t val, uint8_t count, uint8_t delayTime)
{
  int i;

  for (i = 0; i < count; ++i)
  {
    if (bitOrder == LSBFIRST)
      digitalWrite(dataPin, !!(val & (1 << i)));
    else
      digitalWrite(dataPin, !!(val & (1 << ((count - 1) - i))));

    digitalWrite(clockPin, HIGH);
    delayMicroseconds(delayTime);
    digitalWrite(clockPin, LOW);
    delayMicroseconds(delayTime);
  }
}
6 
const int verrou = 10;
//Broche connectée au SH_CP du 74HC595
const int horloge = 12;
//Broche connectée au DS du 74HC595
const int data = 11;
//The 4bytes i want to shift out
byte myData[4] = {0b11001111, 0b00001010, 0b11111111, 0b11111111};
void setup()
{

  pinMode(verrou, OUTPUT);
  pinMode(horloge, OUTPUT);
  pinMode(data, OUTPUT);
}


void loop()
{

  digitalWrite(verrou, LOW);
  for (int i = 0; i < 3; i++)
    shiftOut(data, horloge, MSBFIRST, myData[i]);
  digitalWrite(verrou, HIGH);
  delay(500);

}

Simpler?

7