Yukarıdaki devrede Arduino UNO ve 74HC595 Shift Register ile 7 Segment Displayli Sayıcı Uygulama Devresi görülmektedir.

Bu devrede push butona basılarak 7 segment displayde ileri yönde sayma yapılmaktadır.

Kullanılan Malzemeler : 

Arduino UNO board
4 Digit ortak anotlu 7 segment display
74HC595 shift register
4 x PNP transistor (2SA1015, 2S9015, 2N3906 …)
8 x 100 ohm direnç
4 x 4.7k ohm direnç
Push buton
Breadboard


Arduino Kod :


/*
* 7-segment display with 74HC595 shift register
* 4-Digit counter example.
* Common anode 7-segment display is used.
* This is a free software with NO WARRANTY.
* http://elektrikelektronikegitimi.blogspot.com/
*/

// counter button definition
#define button A0

// shift register pin definitions
#define clockPin 7 // clock pin
#define dataPin 6 // data pin

// common pins of the four digits definitions
#define Dig1 5
#define Dig2 4
#define Dig3 3
#define Dig4 2

// variable declarations
byte current_digit;
int count = 0;
void disp(byte number, bool dec_point = 0);

void setup()
{
pinMode(button, INPUT_PULLUP);
pinMode(Dig1, OUTPUT);
pinMode(Dig2, OUTPUT);
pinMode(Dig3, OUTPUT);
pinMode(Dig4, OUTPUT);
pinMode(clockPin, OUTPUT);
pinMode(dataPin, OUTPUT);

disp_off(); // turn off the display

// Timer1 module overflow interrupt configuration
TCCR1A = 0;
TCCR1B = 1; // enable Timer1 with prescaler = 1 ( 16 ticks each 1 µs)
TCNT1 = 0; // set Timer1 preload value to 0 (reset)
TIMSK1 = 1; // enable Timer1 overflow interrupt
}

ISR(TIMER1_OVF_vect) // Timer1 interrupt service routine (ISR)
{
disp_off(); // turn off the display

switch (current_digit)
{
case 1:
disp(count / 1000); // prepare to display digit 1 (most left)
digitalWrite(Dig1, LOW); // turn on digit 1
break;

case 2:
disp( (count / 100) % 10 ); // prepare to display digit 2
digitalWrite(Dig2, LOW); // turn on digit 2
break;

case 3:
disp( (count / 10) % 10 ); // prepare to display digit 3
digitalWrite(Dig3, LOW); // turn on digit 3
break;

case 4:
disp(count % 10); // prepare to display digit 4 (most right)
digitalWrite(Dig4, LOW); // turn on digit 4
}

current_digit = (current_digit % 4) + 1;
}

// main loop
void loop()
{
if(digitalRead(button) == 0)
{
count++; // increment 'count' by 1
if(count > 9999)
count = 0;
delay(200); // wait 200 milliseconds
}
}

void disp(byte number, bool dec_point)
{
switch (number)
{
case 0: // print 0
shiftOut(dataPin, clockPin, MSBFIRST, 0x02 | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 1: // print 1
shiftOut(dataPin, clockPin, MSBFIRST, 0x9E | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 2: // print 2
shiftOut(dataPin, clockPin, MSBFIRST, 0x24 | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 3: // print 3
shiftOut(dataPin, clockPin, MSBFIRST, 0x0C | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 4: // print 4
shiftOut(dataPin, clockPin, MSBFIRST, 0x98 | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 5: // print 5
shiftOut(dataPin, clockPin, MSBFIRST, 0x48 | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 6: // print 6
shiftOut(dataPin, clockPin, MSBFIRST, 0x40 | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 7: // print 7
shiftOut(dataPin, clockPin, MSBFIRST, 0x1E | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 8: // print 8
shiftOut(dataPin, clockPin, MSBFIRST, !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
break;

case 9: // print 9
shiftOut(dataPin, clockPin, MSBFIRST, 0x08 | !dec_point);
digitalWrite(clockPin, HIGH);
digitalWrite(clockPin, LOW);
}
}

void disp_off()
{
digitalWrite(Dig1, HIGH);
digitalWrite(Dig2, HIGH);
digitalWrite(Dig3, HIGH);
digitalWrite(Dig4, HIGH);
}

// end of code.