Button Pressing

Projects Programming
12

The solution for anything over three buttons is to start using a struct or class. Below uses a struct.

struct BUTTONACTION
{
  byte pin;
  char *txt;
  bool addNewline;
};

A struct is like a record in a phone book with e.g. first name, last name and phone number. The above links a pin (where the button is connected) to a specific text (that will be 'printed' when the button is pressed). The addNewline allows you to send a new line after the text is 'printed'. Keyboard.println() does not seem to send the cursor to the beginning of a new line).

Next you can declare an array with an entry for each button action.

BUTTONACTION buttonActions[] =
{
  {2, "Hello", false},  // pin 2, text to 'print', do not send KEY_RETURN
  {3, "World", true},  // pin 3, text to 'print', send KEY_RETURN
  // add more here
};

In setup(), you can set all the pins to INPUT_PULLUP.

void setup()
{
  // start keyboard functionality
  Keyboard.begin();

  //setup all button pins for INPUT_PULLUP; buttons need to be wired between pin and ground
  for (int cnt = 0; cnt < sizeof(buttonActions) / sizeof(buttonActions[0]); cnt++)
  {
    pinMode(buttonActions[cnt].pin, INPUT_PULLUP);
  }
}

And in loop you can loop through the array

void loop()
{
  static int buttonNumber = 0;

  if(digitalRead(buttonActions[buttonNumber].pin) == ISPRESSED)
  {
    Keyboard.print(buttonActions[buttonNumber].txt);
    if(buttonActions[buttonNumber].addNewline== true)
    {
        Keyboard.write(KEY_RETURN);
    }
    
    // a crude debounce
    delay(100);

    // wait for button to be released
    while (digitalRead(buttonActions[buttonNumber].pin) == ISPRESSED)
    {
      // do nothing
    }
  }

  // next button
  buttonNumber++;
  if(buttonNumber == sizeof(buttonActions) / sizeof(buttonActions[0]))
  {
    buttonNumber = 0;
  }
}

Compiles, not tested.