Driving multiple leds via Flex Sensor

        There are three leds that are composed of a green, a yellow and a red led (like a traffic lamb). The flex sensor provides us to be able to switch between these three leds and ligth one of them at a time.

        The circuit diagrams (one made on digital environment, the other one is the implemented) and the datasheet of shift register can be seen below:

Digital Drawed Circuit

Implemented Circuit

      Here is a video available to see the outputs and how the system works:

Arduino Code :

/*
    Can KAVALOĞLU
 */
int greenPin = 8;
int yellowPin = 9;
int redPin = 10;
int flexValue;

void setup(){
    pinMode(flexPin, INPUT);
    pinMode(greenPin, OUTPUT);
    pinMode(yellowPin, OUTPUT);
    pinMode(redPin, OUTPUT);    
    Serial.begin(9600);
}

void loop(){
  flexValue = analogRead(flexPin);
  flexValue = constrain(flexValue, 720, 950);
  flexValue = map(flexValue, 720, 950, 0, 1024);
  if(flexValue < 350){
    digitalWrite(greenPin, HIGH);
    digitalWrite(yellowPin, LOW);
    digitalWrite(redPin, LOW);  
  }
  else if(flexValue < 600){
    digitalWrite(greenPin, LOW);
    digitalWrite(yellowPin, HIGH);
    digitalWrite(redPin, LOW);  
  }
  else{
    digitalWrite(greenPin, LOW);
    digitalWrite(yellowPin, LOW);
    digitalWrite(redPin, HIGH);  
  }
  Serial.println(flexValue);  
  delay(200);
}