With apologies to Paul Simon…
Having locked myself out of house on several occasions I decided to fix the problem with having an RFID door lock and an implanted tag. The door lock was no problem but the implanted tag gave me pause for thought. But then I thought, what is I always wear when I’m out? Shoes! Obviously whenever I’m out I’m wearing shoes!! Just put the RFID cards/tags in all of my shoes. Problem solved. Since I only own two pairs of shoes this is not too difficult to achieve. There is of course the corner case when I’m putting my bins (trash) out whilst wearing my dressing gown and in bare feet but this is unlikely to cause me to be locked out.
Ah, but not quite so easy as that. I wanted to build the entire system myself. I’m not one to be happy to buy a system that, almost, does what I want. I want a system that does exactly what I want. Did I mention I also wanted a bluetooth interface? Anyway, I do, so I can open the door with my Android ‘phone. Also I can give people guest access. Not that I ever have any guests these days.
Anyway, it’s now built and installed, so I can open the door with my shoe, key, wallet or ‘phone. I need never climb over the neighbors wall again. Which is a bit risky late at night as there’s a large drop into into the next terrace’s garden, being as I live on a hill.
Technical details follow: Obviously some variety of Atmega(8) was going to be involved. I found some really cheap Chinese RFID readers, (I bought two), that output Wiegand code plus a really cheap bluetooth module, add an electric door catch and I was set to go. A bit of wiring and programming later, combined with some cheap RFID access cards, I have a custom door lock that I can open with my shoe. Total cost approx £22. Labour is not included as I count it as a learning asset rather than a cost.
Also handy if I’m ever laid up in bed and I need to open the door for visitors via my laptop or ‘phone. Giving out key cards is not an issue either as I can always cancel them when I decide they are no longer welcome to my domicile.