This is a bit enhanced version of the “hello world” blink application for Arduino: traffic lights emulator. The top three LEDs control car traffic and the bottom two are fore pedestrians.
int carRedPin = 13;
int carYellowPin = 12;
int carGreenPin = 11;
int pedestrianRedPin = 10;
int pedestrianGreenPin = 9;
// The setup() method runs once, when the sketch starts
void setup() {
pinMode(carRedPin, OUTPUT);
pinMode(carYellowPin, OUTPUT);
pinMode(carGreenPin, OUTPUT);
pinMode(pedestrianRedPin, OUTPUT);
pinMode(pedestrianGreenPin, OUTPUT);
}
// the loop() method runs over and over again,
// as long as the Arduino has power
void blink(int light)
{
digitalWrite(light, LOW);
delay(500);
digitalWrite(light, HIGH);
delay(500);
digitalWrite(light, LOW);
delay(500);
digitalWrite(light, HIGH);
delay(500);
digitalWrite(light, LOW);
delay(500);
digitalWrite(light, HIGH);
delay(500);
digitalWrite(light, LOW);
}
void loop()
{
digitalWrite(carRedPin, HIGH);
digitalWrite(pedestrianGreenPin, HIGH);
delay(3000);
blink(pedestrianGreenPin);
digitalWrite(pedestrianRedPin, HIGH);
digitalWrite(pedestrianGreenPin, LOW);
delay(1000);
digitalWrite(carYellowPin, HIGH);
delay(1000);
digitalWrite(carRedPin, LOW);
digitalWrite(carYellowPin, LOW);
digitalWrite(carGreenPin, HIGH);
delay(3000);
blink(carGreenPin);
digitalWrite(carYellowPin, HIGH);
delay(2000);
digitalWrite(carYellowPin, LOW);
digitalWrite(carRedPin, HIGH);
delay(1000);
digitalWrite(pedestrianRedPin, LOW);
}
The code above is straightforward: just enabling and disabling LED at certain time. Traffic lights in action:
[youtube]http://www.youtube.com/watch?v=f4jVitaSPGg[/youtube]
Nice, thank You for sharing :D
THANKS , i always thought that this project would be difficult , but it seems as u said STRAIGHTFORWARD ;)
thank you , it is very usefull ,but you can reduce it you don’t need car green blinking
Can’t see any current limiting resistors. Are the outputs of the IC current limited or do the leds have built in resistors? If not the Arduino could be damaged
You are right! This was one of my first projects on Arduino so I didn’t know that there should be current limiting resistors for each LED. They should be added in series to the LEDs, but you probably know that already ;)
please how can i use the same idea to construct an intelligent traffic light( i mean the program code needed)
Can you please explain by what you mean “intelligent traffic light”?