Going round in circles searching for info on this.
I'd like to have a deadbolt unlock when someone approaches with a key their pocket rather than having to reach in and find it and press it up against a receiver.
I keep reading that with the 13.56 frequency, 1m+ range should be possible without active keys.
But I can't find any hardware that supports this.
Even on the shy side of 1m would be fine. I imagine walking up to the door and it magically unlocks just before reaching out to push it open so even 70 or 80cm would work.
Anyone?
I keep reading that with the 13.56 frequency, 1m+ range should be possible without active keys.
But I can't find any hardware that supports this.
Just because it's on the internet doesn't mean that it is right. 1 meter + for passive keys is only possible with a big, high power antenna.
Signed up to post here,
I am interested in doing this as well. Right now the best option to me looks like using a bluetooth module and then detecting of my device (cell phone in my pocket) is in range, then unlocking the door. Here is a link: http://www.fritz-hut.com/2012/08/26/bluetooth-presence-detection/
Only problem with this seems to be the timing; if it takes 10 seconds for the system to register that I'm at the door then I could get my keys out faster than that. However I haven't tried it yet so I'm not sure how fast it will be.
Another option would be to use something like this http://www.adafruit.com/products/1392 and set up an attiny or something to just constantly press that button while in my pocket (maybe once every 3 seconds). Hopefully that doesn't draw too much power and can be left on for days.