Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: roborg on April 21, 2010, 06:39:18 PM

Title: Direction of RFID signal
Post by: roborg on April 21, 2010, 06:39:18 PM

Hi,

I am wondering if a RFID reader can tell (approximately) which direction the RFID transmitter is ? and how far the trasmitter is ? I am wondering if there is a way to compute it based on signal strength and may be other properties when the signal is being processed.

Thanks,
RO.

Title: Re: Direction of RFID signal
Post by: Soeren on April 22, 2010, 04:47:57 PM

Hi,

Quote from: roborg on April 21, 2010, 06:39:18 PM

I am wondering if a RFID reader can tell (approximately) which direction the RFID transmitter is ? and how far the transmitter is ? I am wondering if there is a way to compute it based on signal strength and may be other properties when the signal is being processed.

A regular passive RFID device haven't got current for anything but responding with its code.
You could let the transponder badge have it's own supply and sensors (distance, GPS etc) and read that data back when polled, but then it sort of makes using RFID obsolete, as there are better ways for that.

So, the short answer is no.

Title: Re: Direction of RFID signal
Post by: madsci1016 on April 22, 2010, 05:18:45 PM

I am actually working on a project with RFID tags.

For passive tags: No, for everything Soeren said.

Different story for active tags. We actually have a hand-held reader that has a 'search' mode that just beeps faster and faster as it's looking at / approaching the tag you want to find. It works starting at about 20 feet away.