Arduino - 74HC595 2

<source lang"C">

/* Using 2 7-segment displays with the 74HC595 shift registers CC by-sa-nc 3.0 http://tronixstuff.wordpress.com

*/

int latchpin = 8; // connect to pin 12 on the '595 int clockpin = 12; // connect to pin 11 on the '595 int datapin = 11; // connect to pin 14 on the '595 float b = 0; int c = 0; float d = 0; int e = 0; int speed = 300; // used to control speed of counting int segdisp[10] = {

3,159,37,13,153,73,65,27,1,9 };

void setup() {

pinMode(latchpin, OUTPUT);
pinMode(clockpin, OUTPUT);
pinMode(datapin, OUTPUT);

} void loop() {

//  Count up
for (int z=0; z<100; z++)
{
  digitalWrite(latchpin, LOW);
  shiftOut(datapin, clockpin, LSBFIRST, 0); // clears the right display
  shiftOut(datapin, clockpin, LSBFIRST, 0); // clears the left display
  digitalWrite(latchpin, HIGH);
  if (z<10)
  {
    digitalWrite(latchpin, LOW);
    shiftOut(datapin, clockpin, LSBFIRST, segdisp[z]); // sends the digit down the serial path
    shiftOut(datapin, clockpin, LSBFIRST, 255); // sends a blank down the serial path to push the digit to the right
    digitalWrite(latchpin, HIGH);
  }
  else if (z>=10)
  {
    d=z%10; // find the remainder of dividing z by 10, this will be the right-hand digit
    c=int(d); // make it an integer, c is the right hand digit
    b=z/10; // divide z by 10 - the whole number value will be the left-hand digit
    e = int(b); // e is the left hand digit
    digitalWrite(latchpin, LOW); // send the digits down to the shift registers!
    shiftOut(datapin, clockpin, LSBFIRST, segdisp[c]); 
    shiftOut(datapin, clockpin, LSBFIRST, segdisp[e]); 
    digitalWrite(latchpin, HIGH);
  }
  delay(speed);
}
delay(2000);
//  Count down
for (int z=99; z>=0; z--)
{
  digitalWrite(latchpin, LOW);
  shiftOut(datapin, clockpin, LSBFIRST, 0); // clears the right display
  shiftOut(datapin, clockpin, LSBFIRST, 0); // clears the left display
  digitalWrite(latchpin, HIGH);
  if (z<10)
  {
    digitalWrite(latchpin, LOW);
    shiftOut(datapin, clockpin, LSBFIRST, segdisp[z]); // sends the digit down the serial path
    shiftOut(datapin, clockpin, LSBFIRST, 255); // sends a blank down the serial path to push the digit to the right
    digitalWrite(latchpin, HIGH);
  }
  else if (z>=10)
  {
    d=z%10; // find the remainder of dividing z by 10, this will be the right-hand digit
    c=int(d); // make it an integer, c is the right hand digit
    b=z/10; // divide z by 10 - the whole number value will be the left-hand digit
    e = int(b); // e is the left hand digit
    digitalWrite(latchpin, LOW); // send the digits down to the shift registers!
    shiftOut(datapin, clockpin, LSBFIRST, segdisp[c]); 
    shiftOut(datapin, clockpin, LSBFIRST, segdisp[e]); 
    digitalWrite(latchpin, HIGH);
  }
  delay(speed);
}

  delay(2000);

}