Currently, there is a good debouncing implementation for the switches.
But this does not apply anymore when configuring an input as button
for the usage at a blind. Then, the current implemntation works by
just checking the input once per debounce interval. At some devices,
this causes ghost switching. As a result, this change checks the
input twice per devounce interval and uses the old values if the two
read attempts reported different values.