/* * Loop * Lights multiple LEDs in sequence, then in reverse. Demonstrates * the use of a for() loop and arrays. * project tutorial: http://osoyoo.com/?p=112 */ int timer = 100; // The higher the number, the slower the timing. int pins[] = { 2, 3, 4, 5, 6, 7 }; // an array of pin numbers int num_pins = 6; // the number of pins (i.e. the length of the array) void setup() { int i; for (i = 0; i < num_pins; i++) // the array elements are numbered from 0 to num_pins - 1 pinMode(pins[i], OUTPUT); // set each pin as an output } void loop() { int i; for (i = 0; i < num_pins; i++) { // loop through each pin... digitalWrite(pins[i], HIGH); // turning it on, delay(timer); // pausing, digitalWrite(pins[i], LOW); // and turning it off. } for (i = num_pins - 1; i >= 0; i--) { digitalWrite(pins[i], HIGH); delay(timer); digitalWrite(pins[i], LOW); } }