SOS with variables

In the previous code we have an SOS with simple instructions. We are going to convert simple instructions in to instructions with variables. Variables are declared(defined) at the begining of the code. Remember that there are many types of variales (int, byte, float, bool, double, char, etc), those variables can be signed or unsigned, global variables are used all along the code, and local variables are used only inside a function and do not exist outside that specific function. In this case the globa variable t=200; sometimes a variable can be constant in all the code so I can declare const int t=200;. When I declare a variable the computer keeps a space in the memory fot that variable and keeps that name.

What is the advantage of creating variables? You don't need to repeat all the time the same value, it's more effective because I write once and the values changes many times.

Time variables is sometime t and sometimes 3*t or 7*t because the rules of the Morse code are:

• A dot lasts for one unit of time.
• A dash last for three units of times.
• The space between dots and dashes that are part of the same letter is one unit of time.
• The space between different letters is three units of time.
• The space between different words is seven units of time.

Another possibility is to creat 3 variables one is dot, another is dash, and the other one is space, the code will be: const int dot= 200; const int dash= dot*3; const int space= dot*7;

The structure of the code is always the same:

1. Comment about the objective and author of the code
2. Importing libraries needed for my code for example: if I'm using computer vision I need to import the computer vision libary in order to use the computer vision instrucions
3. Setup function contains the settings of my code: outputs or inputs, screen size, etc
4. My own functions created by myself in this case to be use in the main code
5. The main code is the loop function and in this case contains only simple instructions with variable and do not call any function created by myself

const int t =200; global variable



void setup() {

  // put your setup code here, to run once:
pinMode(LED_BUILTIN, OUTPUT);
}

void loop() { 
  
// const int t =200; local variable
  

 digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(t);                       // wait for a second
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(t);                       // wait for a second digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(3*t);                       // wait for a second digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(3*t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(t);                       // wait for a second digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(3*t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(t);                       // wait for a second digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
   digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(3*t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(3*t);                       // wait for a second digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
   digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(t);                       // wait for a second digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
   digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(t);                       // wait for a second digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
   digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(t);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(7*t);                       // wait for a second digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level) 
}