Digital or analog Write multiple pins in one command ?

[mektek 0]

digitalWrite(12, LOW);

 

digitalWrite(10, LOW);

 

digitalWrite(8, LOW);

 

digitalWrite(6, LOW);

 

Is there a way to combine these four commands in one command?

 

thanks in advance

[energia 484]

You could if you would use pin 9 instead of 6. We will have to get into the nitty gritty details of port registers though. The idea is that the pins you want to control at the same time are on the same port. In this case P2. Assuming that you do a pinMode(xxx, OUTPUT) on all your pins in setup then you can do the following to set all pins at once.

 

First let's figure out which port bits are associated with the pins. If you use pin 8, 9, 10 and 12 then:

 

8  = P2.0 = bit 0 = 1 < 0
9  = P2.1 = bit 1 = 1 < 1
10 = P2.2 = bit 2 = 1 < 2
12 = P2.4 = bit 4 = 1 < 4

 

To set all bits at once you would do:

P2OUT |= (1 < 0) | (1 < 1) | (1 < 2) | (1 < 4);

to clear all bits at once you would do:

 

 

P2OUT &= ~((1 < 0) | (1 < 1) | (1 < 2) | (1 < 4));

 

In your loop() it would look something like this.

 

loop() {
 /* Turn all LED's on */
 P2OUT |= (1 < 0) | (1 < 1) | (1 < 2) | (1 < 4);
 delay(500);
 /* Turn all LED's off */
 P2OUT &= ~((1 < 0) | (1 < 1) | (1 < 2) | (1 < 4));
 delay(500);
}

[oscarl1718 0]

I am doind a DC-AC inverter, and i need to toggle two pins at the same time, but i need a 1us accuracy, but for example, there is a 3us delay between a HIGH and a LOW for Q1 and Q2, thar are always complementary. This is my code:

 

//Primer semiciclo
  //2)Q1 y Q4
  digitalWrite(Q2,LOW); digitalWrite(Q3,LOW);	 //Q2 y Q3 apagado
     //delayMicroseconds(td);						  //Tiempo muerto
  digitalWrite(Q1,HIGH); digitalWrite(Q4,HIGH);   //Q1 y Q4 ENCENDIDO
  delayMicroseconds(duty);					    //Duracion del semiciclo (T/4)
  //1)Q2 y Q4
  digitalWrite(Q3,LOW); digitalWrite(Q1,LOW);	  //Q1 y Q3 apagado
     //delayMicroseconds(td);						   //Tiempo muerto
  digitalWrite(Q4,HIGH); digitalWrite(Q2,HIGH);    //Q4 y Q2 ENCENDIDO
  delayMicroseconds(tr-duty);					  //Duracion del semiciclo (T/4)

  //Segundo semiciclo

//2)Q1 y Q4
     digitalWrite(Q2,LOW); digitalWrite(Q3,LOW);     //Q2 y Q3 apagado
     //delayMicroseconds(td);                          //Tiempo muerto
     digitalWrite(Q1,HIGH); digitalWrite(Q4,HIGH);   //Q1 y Q4 ENCENDIDO
     delayMicroseconds(duty); 
  //3)Q2 y Q4
  digitalWrite(Q3,LOW);digitalWrite(Q1,LOW);	    //Q1 y Q3 apagado
     //delayMicroseconds(td);						    //Tiempo muerto
  digitalWrite(Q4,HIGH);digitalWrite(Q2,HIGH);    //Q2 y Q4 ENCENDIDO
  delayMicroseconds(tr-duty);					   //Duracion del semiciclo (T/4)

 

is there any chance to get a better response time? maybe with some modification like you suggested in this post? i mean... is faster to set and clear this bits in this way than if i use digitalWrite?

 

Thanks a lot for your Help.

[jsolarski 94]

Yes you can get faster results but you either have to code it in C and interface with the registers directly

I.E. P1OUT |= bit1+ bit2 or P1OUT &= ~bit1 + bit2

the other option is code it in assembly

[oscarl1718 0]

Yes!! this is just what i was needing... thanks a lot for your help.