• 255 if the pin was in the active state for given period.
• 0 otherwise

Function eliminates the influence of contact flickering upon pressing a button (debouncing).

Parameter port specifies the location of the button; parameter pin is the pin number on designated port and goes from 0..7; parameter time is a debounce period in milliseconds; parameter active_state can be either 0 or 1, and it determines if the button is active upon logical zero or logical one.

Button pin must be configured as input.

Example reads RB0, to which the button is connected; on transition from 1 to 0 (release of button), PORTD is inverted:

while true do
begin
  if Button(PORTB, 0, 1, 1) then oldstate := 255;
  if oldstate and Button(PORTB, 0, 1, 0) then
  begin
    PORTD := not(PORTD);
    oldstate := 0;
  end;
end;