I have 15 sonoff dw2 door window sensors.
They only report when a door is open, not when it closes.
Question 1, is it possible to amend the firmware to make it trigger on both open and close, if so how?
Question 2, these are useless to me in their current state and I’d be happy to sell them on if someone has a use for them?
Ooooor, can anyone think of a use case for these sensors?
Thanks
Colin
Does it report open continually or just when opened?
Expire timer wouldxwork on former
only when the reed sensor detects the opening of the door, so just a single message.
Expire timer might work, but rarely do i want to know when a door is only open, i usually want to know when it’s closed also
They only show if open because they are usually set to an alarm system and therefore only need to know if the door or window has been opened.
I bought 10 of those by mistake and haven’t even got them out of the packaging.
I wanted to order the Sonoff ZibBee SNZB-04 which does open and closed and also battery status. I clicked the wrong picture. 
I have 15 unopened here, with a further 5 opened 
Stupidly I thought a doorsensor would indicate the open/closed state too and bought a bunch of them. Unfortunately I purchased them in China so I cant return them. So a bit late to this conversation, but for what its worth I made a mod / hack that sends the close status as a new code. However you need a transistor and two resistors for this (1k and 10k ohm) . This is surely not the most efficient way to do it but it works. You get two individual codes for the open / closed state.
Thought I would share this as it would be sad to waste those sensors. With the mod the sensor still fits in the box so no biggy.
Haha l love it!
I actually sold them on. I was very honest about the shortcomings when I sold all of them, and have away a load of X10 stuff to someone around out on their HA journey
