This is Blinking 3, on this blinking you can found variables and functions.
The function of this code is to can can make the morse code, with the green and red LEDS with functions and variables:
const int t = 200 ; /* Blink Turns an LED on for one second, then off for one second, repeatedly. Most Arduinos have an on-board LED you can control. On the UNO, MEGA and ZERO it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN is set to the correct LED pin independent of which board is used. If you want to know what pin the on-board LED is connected to on your Arduino model, check the Technical Specs of your board at: https://www.arduino.cc/en/Main/Products modified 8 May 2014 by Scott Fitzgerald modified 2 Sep 2016 by Arturo Guadalupi modified 8 Sep 2016 by Colby Newman This example code is in the public domain. https://www.arduino.cc/en/Tutorial/BuiltInExamples/Blink */ // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin LED_BUILTIN as an output. pinMode(LED_BUILTIN, OUTPUT); } // the loop function runs over and over again forever void loop() { void S (){ digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) } void O (){ delay(3*t); digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(3*t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(3*t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(3*t); digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(3*t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(3*t); digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(3*t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(3*t); } digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(t); digitalWrite(LED_BUILTIN, LOW); // turn the LED on (HIGH is the voltage level) delay(7*t); void loop () { S (); O (); S (); }