Entering your home with just a tap (using NFC & iOS)

As you might have guessed from a previous post, I’m not a fan of carrying keys and or even having to use them. When I moved to a new place, I knew I’d use the front door as my main point of entry (instead of a garage attached to a house), so I wanted to get it as automated as possible, where the front door unlocks as I approach it, and locks when I leave. This is both because I’m lazy but also so I can waltz in with my hands full and not need to fish for my keys.

I replaced the back of my deadbolt front door lock with an August Smart Lock Pro with a Connect module to communicate with it over WiFi. I had one at my old house, so it wasn’t too hard to setup again. Once you’ve got it installed, you can use the August app to lock and unlock remotely, or grant new “keys” to anyone with the app. It also talks to Homekit, so you can ask Siri to lock and unlock the door.

Homekit also lets you use simple geo-fencing to lock the door when you leave your neighborhood or when you return, but with three different people in my house on three separate schedules, I could never get it to work reliably and I didn’t want to accidentally ever lock someone out if they were doing yard work without a phone in their pocket as I drove away.

So instead I tried another way to automate this. I’ve been tinkering around with the new Shortcuts app and I found the support for reading NFC chips in the newest iPhones intriguing. I saw this video of how to set it all up and got excited to try it out myself:

First, I bought a 10-pack of blank white NFC discs on amazon for just under $10. It’s kind of amazing that these powerful stickers don’t need batteries or wifi or anything and cost less than a buck each. You can tie any iOS Shortcut to a NFC tap, and I’ve heard a few good ones like Merlin Mann who uses it to “move whatever podcast I was playing on my phone to my Homepod” when he gets to his home or office.

I tapped one of the NFC discs on my desk, and set it up to run a custom “unlock front door” shortcut just for my phone (other people can’t tap it and get anything to run). Then I setup a second one to “lock the front door” as well. Then I stuck them outside on some posts, one leading towards the front door (to open) and another on the first post on the way out (to lock).

Here’s what they look like mounted on a post outside:

They’re white and metal, and you can paint them to match whatever you’ve mounted them to. They look best when they blend in mostly with your wall. They shouldn’t be completely camouflaged or you won’t be able to find them easily.

To make them blend in a bit more, I went to my local Lowe’s and bought a $5 roll of adhesive-backed shelf paper in a maple pattern that mostly matched my wood posts. I used a NFC tag as a template, traced it onto the paper, and cut out two holes, then pulled off the backing and stuck them over the tags. From a distance, you can barely tell they’re there since I put the NFC stickers over wood knots and they look like wood repair patches now.

Now, whenever I leave the house or come back to it, I just tap the top half of my phone over the NFC sticker and I hear the cheerful chime from the August deadbolt locking or unlocking.

A couple things to keep in mind:

  1. You have to setup a custom shortcut for each person you want access to this, but it’s been surprisingly reliable for a bunch of somewhat buggy IoT products strung together. In the last three months it’s worked as expected about 100 times. I’ve only had it not run once or twice, and instead I had to go into the August lock app to make sure something locked or unlocked. For typical Homekit IoT devices, this is an amazing success rate, I feel like most things in my house over Homekit only work about 75% of the time.
  2. You need a modern iPhone from the last couple years. NFC doesn’t work on a iPhone X or earlier, only XR, Xs, and 11 and up phones (and yes, this is where Android was years ahead in support and what you can do with NFC chips).

Remember all the rage around Facebook and Apple’s use of beacons? I’d actually love to have that instead of NFC at my own home, so whenever I enter my driveway or pass my mailbox, it could open the garage door automatically, turn on some pathway lights, and unlock my front door. I’m still searching for a way to do all that, but for now NFC tags are a cheap, reliable, and easy way to automate physical things.