RFID Door Unlocker

Nervous About Hardware for Some Reason

by Cory on April 13, 2019 12:44 PM

I was thinking about what to do about mounting the arduino to the door and how to attach the servo to the deadbolt. I don't know why, but thinking about it stresses me out trying to figure out how to get 3d printed stuff or buying cases. I've been putting off working on this for a while partially because of it...

Last night I decided to just put together some prototype code. That is, hook up a servo, the rfid reader, and a buzzer together and try to write code that will turn the servo and beep when a card is detected. So here's the thing so far:

Ignore the dust. I'll move into a nicer apartment some day...

It was an easy win. :) I added some state so that the servo turns back to the locked position after a timeout only if the card is no longer detected. I felt good about it so I put it up on github.

The next easiest thing to do I think is to add some RSA keys or encryption so that it doesn't just accept any old card. After that I need to add a battery pack and servo mounts to see if this tiny servo has enough torque to turn the deadbolt (just from feeling it, I'm pretty confident it does).

Have a random picture of an RFID PICC fob: 

I also found this nice page when looking for power requirements for arduino power supplies:


Some good shit here. Apparently my UNO won't even last a day on a 9V battery. I'm probably gonna have to buy/build the pro mini and do all the modifications in this article for the final thing, so that's good to know.

Good thing I didn't start with the casing.

This Thought is part of RFID Door Unlocker

You know how nice cars like Mercedes or Tesla automatically unlock when you get close to them with the key fob? Let's do that but for my apartment front door.

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