I am currently building a smart cat door. One of its functionalities is that it keeps the door locked until our cat comes close to it, then it unlocks the door.
I tried using RFID, the RC522 because I read that it can work fr a range of 1m. But after testing, the max range I could get out of it was less than 10cm.
After doing some research I found out that the protocol used in the RC522 can't do more than 10cm.
Another solution I came up with was to use Bluetooth instead, but the problem with Bluetooth is that it has a long detection distance for our application (with class 2 having a range of 10m). This will mean the door will detects the cat even if she is just setting in it's vicinity and we don't want that.
Is there any other sensor combination that can accomplish this task?
- It doesn't have to be RFID or Bluetooth.
- It has to detect the cat at a short range, lets say no >2 meters and no <1 meter.
- It is preferable if the tag/module that goes on the cat is unpowered, or requires low power.