Comments on: Controlling a Seven-Segment Display Using Arduino Part 2

By: Natalia

Natalia — Tue, 30 Aug 2011 20:50:47 +0000

Thanks for stopping by, and I appreciate your input. You are right about the delays. I guess what happens is that beginner hobbyists are not yet creating projects that need to maximize use of those processor cycles. At this point all I do is overkill and inefficient, but I still have fun! Your vintage display sure looks cool, and I’ve bookmarked the sketch. Thanks for sharing!

By: ElectroNick

ElectroNick — Tue, 30 Aug 2011 20:31:17 +0000

Not to beat a dead horse, guys, but I find the use of delay in software servicing displays of any kind to be a disadvantage, really. The 5-10ms refresh delay needed for creating a stable non-flickering image on a multi-digit 7-segment display means that you’re forcing the processor to stay put for the time it would have taken it to execute a thousand or so more commands. In other words, the processor pauses exactly where it would have actually done a lot of useful work had you not paused it for the display’s sake.

Anyway, some time ago I’ve posted an Arduino sketch with a non-stopping display refresh:
http://elabz.com/arduino-nano-and-hp5082-7433-vintage-7-segment-led-display/
It can be used in projects where the display function is secondary to something else Arduino is supposed to be doing. Like I said, a lot of useful work can be done during the time otherwise taken by the display pause.

Keep up great work!

Cheers!

By: João Alexandre da Silveira

João Alexandre da Silveira — Thu, 17 Jun 2010 00:58:21 +0000

Here is another sketch to show the position of a 10k potentiometer in the Arduino analog pin 0 in 0-9 digits in a 7-segments display.

/*
potDigital
Mostra a posição de um potenciometro no mostrador de 7 segmentos
by João Alexandre da Silveira
http://www.OrdemNatural.Com
16 junho 2010
*/
#define pausa delay(1000) //define uma pausa de 1 segundo

int digito0[7]={1,1,1,1,1,1,0}; //matriz dos segmentos do digito 0
int digito1[7]={0,1,1,0,0,0,0}; //digito 1
int digito2[7]={1,1,0,1,1,0,1}; //digito 2
int digito3[7]={1,1,1,1,0,0,1}; //digito 3
int digito4[7]={0,1,1,0,0,1,1}; //digito 4
int digito5[7]={1,0,1,1,0,1,1}; //digito 5
int digito6[7]={1,0,1,1,1,1,1}; //digito 6
int digito7[7]={1,1,1,0,0,0,0}; //digito 7
int digito8[7]={1,1,1,1,1,1,1}; //digito 8
int digito9[7]={1,1,1,1,0,1,1}; //digito 9

int pinoUSADO[7]={2,3,4,5,6,7,8}; //matriz dos pinos usados no Arduino
int i=0; //contador para a estrutura ‘for’
int potPin=0; //potenciometro no pino 0
int conversor; //

void setup(){
for(i=0; i<7; i++){
pinMode(pinoUSADO[i],OUTPUT); //configura cada pino usado como saida
}
}

void loop(){
conversor=analogRead(potPin)/100; //converte a entrada 0-1024 para a faixa 0-10

switch (conversor) {
case 0:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito0[i]); //acende o digito 0
}
break;

case 1:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito1[i]); //digito 1
}
break;

case 2:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito2[i]); //digito 2
}
break;

case 3:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito3[i]); //digito 3
}
break;

case 4:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito4[i]); //digito 4
}
break;

case 5:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito5[i]); //digito 5
}
break;

case 6:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito6[i]); //digito 6
}
break;

case 7:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito7[i]); //digito 7
}
break;

case 8:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito8[i]); //digito 8
}
break;

case 9:
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito9[i]); //digito 9
}
break;
}
}

By: Natalia

Natalia — Thu, 17 Jun 2010 00:11:41 +0000

I’m originally from Brazil, too, Joao. Thanks for your input. Also, check out the final version I wrote where the segment array for each digit is bit packed and is unpacked using the bitRead function to light each segment. It just makes for shorter code and uses less memory. You can check it out here:
http://www.theelectronicshobbyist.com/blog/2010/02/controlling-a-seven-segment-display-using-arduino-part-4-of-4/

By: João Alexandre da Silveira

João Alexandre da Silveira — Wed, 16 Jun 2010 23:53:12 +0000

I write a new version of this sketch for a common catode dispay. The comments are in portuguese, I am from Brazil. Here it:

/*
Digitos0a9
Mostra a cada segundo os digitos 0 a 9 no mostrador de 7 segmentos
*/
#define pausa delay(1000) //define uma pausa de 1 segundo

int pinoUSADO[7]={2,3,4,5,6,7,8}; //matriz dos pinos usados no Arduino
int i=0; //contador para a estrutura ‘for’

void setup(){
for(i=0; i<7; i++){
pinMode(pinoUSADO[i],OUTPUT); //configura cada pino usado como saida
}
}

void loop(){
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito0[i]); //acende o digito 0
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito1[i]); //digito 1
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito2[i]); //digito 2
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito3[i]); //digito 3
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito4[i]); //digito 4
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito5[i]); //digito 5
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito6[i]); //digito 6
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito7[i]); //digito 7
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito8[i]); //digito 8
}
pausa;
for (i=0; i<7; i++){
digitalWrite(pinoUSADO[i],digito9[i]); //digito 9
}
pausa;
}