スケッチは下記の通りで、前回のBlinkを3個並列にしたような状態。模擬信号は青を長め、黄色を短めの点灯時間としている。

[ スケッチ：Signal1]

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
}
// the loop function runs over and over again forever
void loop() {
  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(7500);                       // wait for a second
  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW
  digitalWrite(12, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(2500);                       // wait for a second
  digitalWrite(12, LOW);    // turn the LED off by making the voltage LOW
  digitalWrite(11, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(5000);                       // wait for a second
  digitalWrite(11, LOW);    // turn the LED off by making the voltage LOW
}

実際に点灯させたところを動画に撮ってみた。実験基板上のLEDが全部赤色なので信号感は無いが、ご容赦のほど。