Video
Circuit Diagram
Source Code
1int ledPins[] = {2, 3, 4, 5, 6, 7};
2
3void setup() {
4 for(int i = 0; i < 6; i++) {
5 pinMode(ledPins[i], OUTPUT);
6 }
7}
8
9void loop() {
10 for(int i = 0; i < 6; i++) {
11 digitalWrite(ledPins[i], HIGH);
12 delay(150);
13 digitalWrite(ledPins[i], LOW);
14 }
15}FAQ
Why is it better to use an array?▾
If you store the pin numbers in an array, you can use a for loop to cycle through all the LEDs in a single line of code. To change the number of LEDs, you just need to update the array; you don't have to write a separate line for each LED.
If 6 LEDs light up at the same time, will the Arduino be damaged?▾
With a 330 Ω resistor, each LED draws approximately 9–10 mA; 6 LEDs total about 60 mA, which is within the Uno’s safe limits. The recommended upper limit for a single pin is 20 mA, and the board’s total I/O current is 200 mA.
How do I reverse the walking direction?▾
Set up the `for` loop in reverse order: `for (int i = 5; i >= 0; i--)`. This way, the light moves in the opposite direction. If you place the two loops one after the other, you’ll get a lightning bolt effect.
One of the LEDs isn't lit—what could be the reason?▾
The LED might be installed upside down, its leg might not be seated properly on the breadboard, or the resistor might be in a different row. You can determine whether the LED is defective or if there’s a connection issue by replacing it with a working LED.