Debouncing Buttons¶
lbuild module: modm:ui:button
The modm::ButtonGroup class is able to debounce eight buttons at the same time.
The buttons have to be low-active. If this isn't the case invert their signal
before passing it to the update() method.
The update() method needs to be called periodically for example
every 10ms. Preferred in a timer interrupt function.
The detection for long or repeated presses works only correctly for
one key at a time. This constraint only applies to buttons listed in the
mask variable.
Mode 1:
Timeline ---->
__ _________________ __
getState() ____/ \____/ \____/ \____
isPressed() ----X-------X----------------------X-------
isRepeated() --------------------X--X--X--X-------------
isReleased() -------X----------------------X-------X----
| |__|__|
|_______| \ /
\ interval
timeout
Mode 2:
__ _________________ __
getState() ____/ \____/ \____/ \____
isPressedShort() -------X------------------------------X----
isPressedLong() --------------------X----------------------
isReleased() -------X----------------------X-------X----
This implementation is based on the C functions written by Peter Dannegger (see http://www.mikrocontroller.net/topic/48465).