Semáforo

1// ─────────────────────────────────────────
2//   BlueGrays · bluegrays.com
3//   Traffic Light
4// ─────────────────────────────────────────
5// Traffic light cycle with red, yellow and green LEDs: red 2 s, yellow 0.3
6// s, green 2 s, yellow 0.3 s, then it starts over.
7//
8// Pins:
9//   D2 -> Red LED
10//   D3 -> Yellow LED
11//   D4 -> Green LED
12//   Each LED with a 330 ohm resistor
13
14void setup() {
15  pinMode(2,OUTPUT);    // Red
16  pinMode(3,OUTPUT);    // Yellow
17  pinMode(4,OUTPUT);    // Green
18}
19
20void loop() {
21  // Red on, wait 2 s
22  digitalWrite(2,HIGH);
23  digitalWrite(3,LOW);
24  digitalWrite(4,LOW);
25  delay(2000);
26  // Yellow on, wait 0.3 s
27  digitalWrite(2,LOW);
28  digitalWrite(3,HIGH);
29  digitalWrite(4,LOW);
30  delay(300);
31  // Green on, wait 2 s
32  digitalWrite(2,LOW);
33  digitalWrite(3,LOW);
34  digitalWrite(4,HIGH);
35  delay(2000);
36  // Yellow on, then back to red
37  digitalWrite(2,LOW);
38  digitalWrite(3,HIGH);
39  digitalWrite(4,LOW);
40  delay(300);
41}
42