RFID Asset Tracking System for Home

Hey guys, I'm trying to make an indoor tracking system for my home. I want to be able to attach electronic tags to my belongings (keys, laptop, phone, etc) and be told what direction they are in, in relation to the reader.

The requirements:

  • A reader's range must be at least 5 meters, preferably higher. I've isolated UHF (900MHz) RFID tags to satisfy this.
  • Of course, the fewer the readers in the home the better. ie. One reader for the house would be awesome, one readeer per room would be ok
  • The tag must be passive
  • The reader must be able to detect the presence of the tag
  • The reader must be able to provide an angle at which the tag is at, in relation to the reader
  • The reader must be stationary; ie. I dont want to rotate the reader in order to find the direction

Ideally, I would want the signal/detection data to be sent to the arduino, and fed into some sort of display that would display either an angle or an arrow in the direction of the tagged object.

The absence of moving parts would be preferred.

Not knowing any way of doing this purely electronically, my initial idea was to place the reader on a rotating motor and have it scan the region radially. Again, I'd prefer the reader to be completely stationary and scan the region without moving.

I was also looking into UHF readers. Has anyone used these with arduinos? http://store.linksprite.com/long-range-integrated-uhf-rfid-reader-ethernet-1-6m-epc-g2/

Are there any suggestions on how to create such a tracking system?

tl;dr: i want to make a radar system for my home to locate tagged objects and their relative position to the reader.

Have you tried FOCUS ? XD



Personally, I can't see how any passive system is going to do what the @post355 wants.

Personally, I can't see how any passive system is going to do what the @post355 wants.

Me neither.

A tag that beeped on command so it could be found would be far easier to implement, and IMO probably easier to use as well.

The main issue is the requirement for a passive system. This required the base station to induce enough energy into a device at a range of at least 5m for it to be either able to transmit its position, or somehow to modulate its absorption of the induction field to such an extent that its detectable by the base station.

Well, I suppose that the original poster didn't require than everyone in the room would still be alive after the EMP pulse used to generate the necessary field :wink:

What about changing to active tags and using animal tracking tags?

When a concept does not work because the technology is not available then we have to change the concept, no?

As I understand it from my pea-sized undestanding of this subject, a passive tag can only reply using the energy gererated by the reader, hence the Electromagnetic Pulse comment above, as it would need a huge amount of energy to evoke a response from the tag. So..giving the tag an energy source of its own (albeit having to replace the batteries in the tags every year or so) might make the idea more workable pehaps? It would also make the system more expensive too.

If you had a reader on each door frame then you could probably detect and log what tags entered the room but you would not know direction they were travelling into/out of the room. (in someone's pocket, for example)

There would need to be at least 2 readers so that you could detect which reader detected the tag first in order to find out which direction it was going. A reader a small way into the room in front of the door would achieve that as the tag would be detected 'approaching' the door and the be detected in the subsequent room as it had left the previous room.