How do I use the controller button pressed command

VEX V5 Technical Support
12

yea, this is used when polling the button, it returns a boolean indicating if the button is currently pressed or not.


Controller1.ButtonA.pressing()

These are used when you want your code to be event based.


Controller.ButtonA.pressed( callback_pressed );
Controller.ButtonA.released( callback_released );

A callback used an an event is running in its own thread, that means you can block using time consuming code or a while loop if you really want to, for example, this code

using namespace vex;

controller p = controller( controllerType::primary );

void b1() {
    Brain.Screen.setPenColor( vex::color::green );

    while( p.ButtonL1.pressing() ) {
      Brain.Screen.printAt( 200, 180, "L1 pressed");
      vex::this_thread::sleep_for(100);
    }
    Brain.Screen.printAt( 200, 180, "             ");
    return;
}

int main() {
  int count = 0;

  p.ButtonL1.pressed( b1 );
  
  while(1) {
    Brain.Screen.printAt( 10, 50, "Hello %d", count++ );
    // Allow other tasks to run
    this_thread::sleep_for(10);
  }
}

Will call the function “b1” when the L1 button is pressed and stay in that function until it is released.