Write a program for Pedestrian Crossing System comprising 4 LED that is Red, Yellow, Green and Blue LED, 5 Resistors and push button interfaced with Arduino Uno. The Blue LED will represent the pedestrian light, while the Red, Yellow, and Green LEDs will represent the traffic light.
Last Updated : 16 Jul 2025
Solution:
const int redled = 2; // RED LED = pin 2
const int yellowled = 3; // YELLOW LED = pin 3
const int greenled = 4; // GREEN LED = pin 4
const int blueled = 5; // BLUE LED = pin 5
const int btnpin = 6; // Button = pin 6
int buttonstate = 0; // Current button state
int lastbtnstate = 0; // Previous button state
void setup(){
pinMode(redled, OUTPUT); // Set RED LED pin as output
pinMode(yellowled, OUTPUT); // Set YELLOW LED pin as output
pinMode(greenled, OUTPUT); // Set GREEN LED pin as output
pinMode(blueled, OUTPUT); // Set BLUE LED pin as output
pinMode(btnpin, INPUT_PULLUP); // Set button pin with internal pull-up resistor
}
void loop(){
buttonstate = digitalRead(btnpin); // Read the button state
// Check for button press (button state changes from HIGH to LOW)
if (buttonstate == LOW && lastbtnstate == HIGH){
// Sequence of LED actions
digitalWrite(greenled, LOW); // Turn off GREEN LED
digitalWrite(yellowled, HIGH); // Turn on YELLOW LED
delay(2000); // Wait for 2 seconds
digitalWrite(yellowled, LOW); // Turn off YELLOW LED
digitalWrite(redled, HIGH); // Turn on RED LED
delay(2000); // Wait for 2 seconds
digitalWrite(blueled, HIGH); // Turn on BLUE LED
delay(5000);
}Meanwhile you can watch this video
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