Using shift registers to control 24 leds with only 3 pins on the arduino

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more fun with shift registers:
adding a potentiometer to control the led being lit up.

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the code:

int dataPin = 11;
int latchPin = 8;
int clockPin = 12;
long unsigned binary[]= {1 , 2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,
32768,65536,131072,262144,524288,1048576,2097152,4194304,8388608};// 24 values since there are 24 leds
// 1 , 10 ,100 , 1000 , 10000 .......  in binary

void setup() {
  //set pins to output so you can control the shift register
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
}
void loop() {
long unsigned  bin=1;
 int pot = analogRead(A0);
int mymap=map(pot,0,1014,1,24);//map the range of the values from led 1 to led 24
bin=binary[mymap-1];//gets into bin the correct value to turn it on from the array
      digitalWrite(latchPin, LOW);
      shiftOut(dataPin, clockPin, MSBFIRST, bin);
      shiftOut(dataPin, clockPin, MSBFIRST,bin>>8); 
        shiftOut(dataPin, clockPin, MSBFIRST,bin>>16); 
      //take the latch pin high so the LEDs will light up:
      digitalWrite(latchPin, HIGH);
    }