4ButtonKeypad/4ButtonKeypad.ino

//Recommend reading: https://www.arduino.cc/reference/en/
 
//Buttons go 1-4 from Top to bottom
 
//This project uses an Arduino Pro Micro (also known as an Arduino Leonardo)

//Includes
//These can be installed in the arduino IDE by clicking on tools in the top bar, then manage libraries.
#include <EasyButton.h>   //Used to define a button and debounces it
#include "HID-Project.h"  //Lets us simulate keyboard presses.

//Pin Definitions. These numbers refer to the physical GPIO pins on the board
//LEDS
#define LED1 3
#define LED2 5
#define LED3 6
#define LED4 9

//Buttons
#define BUTTON1 A3
#define BUTTON2 A2 
#define BUTTON3 A1
#define BUTTON4 A0

const int cintLedOffTime = 60000;   //LED 'OFF' time (milliseconds) is how long LED will remain on for after a button was pressed (For reference: 60,000 = 1 minute)
const int cintDebounceTime = 200;   //DebounceTime (milliseconds) is used with the 'Delay' function to pause code after a button press. This helps to slow 'extra' commands from
                                    //a Button like 'PASTING repeated data'). Increase the 'time' if wishing to 'hold' an action from happening (or repeating) for longer.
                                    //This is currently only used when 'blnDelayActions' becomes 'true'. If it is 'false', then the delay is 'zero'.

unsigned long ledTickTime = 0; 
unsigned long lastPressTime = 0; 
uint8_t ledBrightness = 100; 
bool ledOn = false;
bool blnDelayActions = false;       //Used to SLOW 'button actions' from repeating (ie. it is a simple debounce to retard 'extra' or 'unwanted' actions from Buttons).
bool blnReleaseALLKeys = false;     //Used to control when 'ALL Keyboard Keys should be released'.... OR NOT, where (in some cases) 'Multi-button combinations are required' (eg. 'Hold-Key' actions like Ctr+Alt+Del).
                                    //If 'blnReleaseALLKeys' is set to false (in the running code), then you must also implicitly state what keys should be released (and when).

//Using the EasyButton library we create 4 buttons, with each button being connected to a GPIO pin as defined above, and having a 35ms debounce time. From memory, these do not have internal pullup
//resistors, and are not inverted. Hence the two falses.
EasyButton button1(BUTTON1, 35, false, false);
EasyButton button2(BUTTON2, 35, false, false);
EasyButton button3(BUTTON3, 35, false, false);
EasyButton button4(BUTTON4, 35, false, false);

//Standard Arduino setup function. Code that only needs to run once goes here
void setup() {
  // Send a clean report to the host. This is important on any Arduino type.
  Keyboard.begin();
  Keyboard.end();

  //LEDS - Setting the LED pins to be outputs. Normally, the buttons would be set as inputs, but they are handled by that library.
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);

  //Here we output a PWM signal to the LEDs, where 0 will be off, and 255 is brightest
  analogWrite(LED1, ledBrightness);
  analogWrite(LED2, ledBrightness);
  analogWrite(LED3, ledBrightness);
  analogWrite(LED4, ledBrightness);

  //BUTTONS - setup buttons using library.
  button1.begin();
  button2.begin();
  button3.begin();
  button4.begin();  
}


//Code that is run constantly goes here
void loop() {
  
  //Read all the buttons
  button1.read();
  button2.read();
  button3.read();
  button4.read();


  //This should be pretty self explanitory. Make sure to always release a button.
  //Note1: 'Keyboard.press' code options (for reference)
  //            Keyboard.press(KEY_LEFT_CTRL)
  //            Keyboard.press(KEY_LEFT_ALT)
  //            Keyboard.press(KEY_LEFT_SHIFT)
  //Note2: 'Keyboard.release' code options (for use when blnReleaseALLKeys = false)
  //            Keyboard.release(KEY_SPACE)
  //            Keyboard.release(KEY_LEFT_CTRL)

  if(button1.isPressed())
  {
    // PASTE COMMAND (Ctrl+V)
    Keyboard.press(KEY_LEFT_CTRL);
    Keyboard.write('v');
    lastPressTime = millis();
    blnDelayActions = true;
  }

  else if(button1.wasReleased())
  {
    lastPressTime = millis();
    blnDelayActions = false;
    blnReleaseALLKeys = true;
  }

  if(button2.isPressed())
  {
    // COPY COMMAND (Ctrl+C)
    Keyboard.press(KEY_LEFT_CTRL);
    Keyboard.write('c');
    lastPressTime = millis();
    blnDelayActions = false;
  }

  else if(button2.wasReleased())
  {
    lastPressTime = millis();
    blnDelayActions = false;
    blnReleaseALLKeys = true;
  }

  if(button3.isPressed())
  {
    //CUSTOM TEXT (Message)
    Keyboard.println("Hi there");
    Keyboard.println();
    Keyboard.println("Just confirming that your item is in the mail... See pics.");
    Keyboard.println();
    Keyboard.println("Tracking is available via Australia Post: TMP40083004070052454xxxxx");
    Keyboard.println("Tracking progress applies on business days as it processes through Australia Post facilities..");
    Keyboard.println();
    Keyboard.print("Thank-you and All the best ;)");
    lastPressTime = millis();
    blnDelayActions = true;
  }

  else if(button3.wasReleased())
  {
    lastPressTime = millis();
    blnDelayActions = false;
    blnReleaseALLKeys = true;
  }

  if(button4.isPressed())
  {
    // 'CTRL' KEY (Only)
    Keyboard.press(KEY_LEFT_CTRL);
    lastPressTime = millis();
    blnDelayActions = false;
  }

  else if(button4.wasReleased())
  {
    lastPressTime = millis();
    blnDelayActions = false;
    blnReleaseALLKeys = false;        //When FALSE - you must implicidly release Keys (below)
    Keyboard.release(KEY_LEFT_CTRL);
  }


  // Check if a 'Pause' is required while performing 'Button' action(s): This stops (or rather 'SLOWS') 'repeated button actions' if a button is 'held down too long' (eg. helps stop extra 'PASTE data' commands)
  switch (blnDelayActions)
  {
    case true:
        // Pause
        delay(cintDebounceTime);
        blnDelayActions = false;
        break;
      default:
        // No Delay, or maybe repeat action(s)
        delay(0);
        break;
  }

  // Check if ALL Keyboard Keys should now be released (Usually 'true', but perhaps 'false' if 'multi-button hold combinations' are required)
  switch (blnReleaseALLKeys)
  {
    case true:
        // Release ALL Keyboard Keys (this should almost always be the case)
        Keyboard.releaseAll();
        blnReleaseALLKeys = false;        
        break;
      default:
        // Do NOT Release Keys (IMPORTANT: If here not by default, then you should have already implicidly set what Keys have been (or are to be) released.)
        break;
  }
  
  if((millis() - lastPressTime) > cintLedOffTime)
  {
    ledOn = false;
  }
  else 
  {
    ledOn = true;
  }

     
  if ((millis() - ledTickTime) > 10)
  {
    ledTickTime = millis();
    if(!ledOn && (ledBrightness > 0))
    {
      ledBrightness=ledBrightness-1;
    }
  
    else if(ledOn && (ledBrightness < 100))
    {
      ledBrightness=ledBrightness+10;
    }

    analogWrite(LED1, ledBrightness);
    analogWrite(LED2, ledBrightness);
    analogWrite(LED3, ledBrightness);
    analogWrite(LED4, ledBrightness); 
  }

//  Serial.print("Led Brightness = ");
//  Serial.print(ledBrightness);
//  Serial.print("\t Led State = ");
//  Serial.println(ledOn);

}