I am looking for an RFID system that would meet the following needs: I want to put tags on customers' houses (passive RFID stickers, if possible). My driver would then drive by with an RFID reader in his car, and would be alerted if the device detected a tag so that he could provide services. I found that ultrahigh-frequency (UHF) RFID stickers are the cheapest and are long-range capable. My understanding is that they can return an ID number that I could then use. Is my understanding correct?
The RFID reader is where I face a challenge. I am looking for an inexpensive unit that could work at a range of 10 to 15 meters (32.8 to 49 feet). I would like it to be used with my smartphone (iOS or Android—either via Bluetooth or some other method). If that is not available, I would like to know if there is anything that could display data on a screen as part of the reader, which could be connected to my car's DC outlet.
A low-cost sticker would likely not last very long if stuck to the side of a house. Rain, wind and other elements would likely cause it to fall off within a few weeks. But yes, you would want to use a passive UHF tag since it would offer the read range you require, and at a low cost.
However, there is no reader available that you could connect to your phone that would provide 10 to 15 meters of reading distance. The problem is that emitting sufficient power to achieve that kind of read distance would drain the phone's battery very quickly. There is also no reader that you could connect to the car's DC power, with a screen, that would be able to interrogate tags at that distance. The car's DC outlet would be 12-volt, whereas readers operate at 110 volts. Fixed readers also don't come with screens—they are usually connected to a laptop so a user can view the collected tag-read data.
You could probably jerry-rig a box that contains a fixed passive UHF RFID reader, use a device to convert the car's 12-volt DC adapter to a 110-volt AC current and run the reader, hang a patch antenna in the window and then place a laptop computer on top of the box to read the tags as you drive by. But I would recommend using a tag with a hardened case that could be affixed to a home with screws.
—Mark Roberti, Founder and Editor, RFID Journal
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