I recently got a couple of the Sonoff SNZB-04 contact sensors in for testing. The initial use for this device was to sense the opening of a closet door to turn on the interior light in the closet.
As it turns out, there is approximately a one second delay between the two parts of the sensor separating before it is shown as ‘open’. While this isn’t much of an issue when this switch is used as a window/door alarm, it is rather disconcerting when one opens a closet (or drawer or what have you) and expects the light to go on only to have a VERY noticeable delay. The funny thing is that there is no delay when the contacts are closed.
Question: Is there a window/door sensor that is in a similar price bracket as the Sonoff device but is acting instantly without delay) ?
Edit: I did confirm that the second unit behaves in a similar manner.