Change pin assignments at runtime

[melkati]

Hi.

Thank you very much for your library. Fantastic, a time saver!

I'm using it on a project (a CO2 monitor) and I'm adding the possibility to reverse the display 180º with a menu option. In a board like the TTGO T-Tdisplay, when display is reversed I need also to reverse the functionality of the two buttons it has.

Until now I was initializing buttons as:

Button2 btnUp(BTN_UP);   // Initialize the up button
Button2 btnDwn(BTN_DWN); // Initialize the down button

void buttonsInit() {
  btnUp.setLongClickTime(LONGCLICK_TIME_MS);  
  btnUp.setLongClickHandler([](Button2 &b) { nav.doNav(enterCmd); });
  btnUp.setClickHandler([](Button2 &b) {
    // Up
    nav.doNav(downCmd);
  });

  btnDwn.setLongClickTime(LONGCLICK_TIME_MS);
  btnDwn.setLongClickHandler([](Button2 &b) { nav.doNav(escCmd); });
  btnDwn.setClickHandler([](Button2 &b) {
    // Down
    nav.doNav(upCmd);
  });
}

https://github.com/melkati/CO2-Gadget/blob/8b55114596b1c5b811b091d794e3dccd75928657/CO2_Gadget_Buttons.h#L17-L34

What is the best way to "reverse the buttons" at execution time, so now btnUp is assigned to pin BTN_DWN (instead of BTN_UP) and btnDwn to pin BTN_UP (instead of BTN_DWN)?

[LennartHennigs]

Hey, it's a bit dirty but I think you should be able to "switch" pins by calling begin() on each button with a new pin number as it does not remove all the handlers when called.

[melkati]

Hi.

Thank you.

Finally I created a specific function to reverse buttons. I left it here just in case anyone has this need (specially with so many people utilizing the library AndroidMenu with Buttons2).

void reverseButtons(bool reversed) {
  if (reversed) {
    // Interrupt Service Routine to turn on the display on button UP press
    attachInterrupt(BTN_UP, buttonUpISR, RISING);
    btnDwn.setLongClickTime(LONGCLICK_TIME_MS);
    btnDwn.setLongClickHandler([](Button2 &b) { nav.doNav(enterCmd); });
    btnDwn.setClickHandler([](Button2 &b) {
      nav.doNav(downCmd);
    });

    btnUp.setLongClickTime(LONGCLICK_TIME_MS);
    btnUp.setLongClickHandler([](Button2 &b) { nav.doNav(escCmd); });
    btnUp.setClickHandler([](Button2 &b) {
      nav.doNav(upCmd);
    });
  } else {
    attachInterrupt(BTN_DWN, buttonUpISR, RISING);
    btnUp.setLongClickTime(LONGCLICK_TIME_MS);
    btnUp.setLongClickHandler([](Button2 &b) { nav.doNav(enterCmd); });
    btnUp.setClickHandler([](Button2 &b) {
      nav.doNav(downCmd);
    });

    btnDwn.setLongClickTime(LONGCLICK_TIME_MS);
    btnDwn.setLongClickHandler([](Button2 &b) { nav.doNav(escCmd); });
    btnDwn.setClickHandler([](Button2 &b) {
      nav.doNav(upCmd);
    });
  }
}

Full code here