5 LEDs Running

Components Needed

• 1x ESP32
• 1x USB Programming Cable
• 1x Double Width Breadboard
• 5x Green LEDs
• 5x 220Ω Resistors
• 6x Male-to-Male Jumper Wires

Connections

Using the breadboard, connect the LEDs to the ESP32 as follows:

Anodes:

• LED 1 Anode (Long Leg) → ESP32 D13
• LED 2 Anode (Long Leg) → ESP32 D12
• LED 3 Anode (Long Leg) → ESP32 D14
• LED 4 Anode (Long Leg) → ESP32 D27
• LED 5 Anode (Long Leg) → ESP32 D26

Cathodes:

• LED 1 Cathode (Short Leg) → 220Ω Resistor → GND Rail
• LED 2 Cathode (Short Leg) → 220Ω Resistor → GND Rail
• LED 3 Cathode (Short Leg) → 220Ω Resistor → GND Rail
• LED 4 Cathode (Short Leg) → 220Ω Resistor → GND Rail
• LED 5 Cathode (Short Leg) → 220Ω Resistor → GND Rail
• GND Rail → ESP32 GND

Code

Upload the following code onto the ESP32:

// Pin definitions for LEDs
int ledPins[] = { 13, 12, 14, 27, 26 };
int numLeds = 5;

void setup() {
  // Initialize all LED pins as outputs
  for (int i = 0; i < numLeds; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  // Running from left to right
  for (int i = 0; i < numLeds; i++) {
    digitalWrite(ledPins[i], HIGH);  // Turn on LED
    delay(200);                      // Wait for 200 milliseconds
    digitalWrite(ledPins[i], LOW);   // Turn off LED
  }

  // Running from right to left
  for (int i = numLeds - 1; i >= 0; i--) {
    digitalWrite(ledPins[i], HIGH);  // Turn on LED
    delay(200);                      // Wait for 200 milliseconds
    digitalWrite(ledPins[i], LOW);   // Turn off LED
  }
}

Explanation

In this tutorial, we use 5 LEDs connected to the ESP32. The LEDs will turn on in sequence, first running from left to right and then running from right to left.

The program:

1. Turns on the LEDs one by one from LED 1 to LED 5.
2. After reaching LED 5, it will then turn the LEDs off and start again in the reverse direction, from LED 5 to LED 1.

The sequence will repeat indefinitely, creating a "running" effect.

Results

Once you upload the code, the LEDs will light up one at a time, running left to right, and then reverse the sequence, running right to left.

Try for Yourself

1. Experiment by changing the delay time to make the LEDs run faster or slower.
2. Modify the sequence to add a delay after all LEDs are lit up.