Logical operators

This example is for Wiring version 0024+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

Increment Decrement. by BARRAGAN

Writing "a++" is equivalent to "a = a + 1". Writing "a--" is equivalent to "a = a - 1".


int current = 0;  // variable the keeps which light must be turn on next 

void setup() { 
  for(int i=0; i<8; i++) {  // set pins 0-7 as outputs 
    pinMode(i, OUTPUT);  
  } 
} 

void loop() { 
  turn_all_off();  // turns all LEDs off 
  digitalWrite(current, HIGH);  // set the current light ON 
  delay(200);  // wait for 200ms 
  current++;  // increment current LED 
  if(current > 7) {  // range check, if last LED goes back to LED 0 
    current = 0; 
  } 
}

void turn_all_off() {  // function to turn off all the LEDs            
  for(int i=0; i<8; i++) {  // connected to digital pins 0-7
    digitalWrite(i, LOW); 
  } 
}