29th May 2012, 10:57 PM
Automated Home Jr Member
Setup dwell time for digital inputs
I have a garage door closure sensor connected to a digital input on a QRI. When the door closes, the sensor state changes 3 times in a very short time 'closed/opened/closed' instead of one change. Similarly, when I open the door, I get 'open/close/open' instead of just 'open'.
In consequence, when I try to use voice announcements, I get 3 messages instead of just one.
Is there any way to setup something like a dwell time for a door/digital input in the same way as for a PIR? I tried to configure the door sensor input as a PIR, but only IDRA PIR modules have the dwell time option.
As an alternative, I should probably use a macro or a delay gate to eliminate the erroneous messages.
1st June 2012, 12:16 AM
Automated Home Legend
Digital inputs do have two steps of filtering - one is capacitive and the other is in the firmware where the signal must remain steady for a certain number of samples but this is not user configurable. I'm not really sure from your description whether the observed signal states are deliberate or whether they are just contact bounce. If it is the latter then they will be very closely spaced eg. tens of ms and might be appropriate to filter for example with additional capacitance. However if deliberate and more widely spaced and probably in any case it might be just easier to use the delay gate idea.