Long range RFID?
W9GFO
Posts: 4,010
I've already spent a bit of time searching for some examples of long range RFID but have not happened across anything useful yet. Just really expensive commercial inventory tracking stuff. I'm looking for a reader and passive tags that can be read up to about two meters away. Can anyone point me to some info on this?
Comments
Oops.. sorry I missed that somehow...
I have found some Long range 125kHz readers that claim to read at up to 60cm using normal tags or 100cm using long range tags. Not the two meters I was hoping for but it may work for what I need.
The 900 mHz readers and tags are also of interest with their read range up to 15 meters. According to the app note Tracy mentioned the 900mHz ones are quite sensitive to tag orientation and other obstacles. I wonder if they can be read at two meters in unfavorable conditions.
The advantage of the wakeup receivers is that they operate on a couple of microamps, and then wake up when they hear an AM header burst that makes it through their correlator. I'm looking for something too, that can operate on microamps, and then wake up an XBee when needed.
The card type is readable using my Parallax RFID Reader when presented edge-on through my 1" thick desktop. When face-on it reads about three inches away. The key fob tags need to be about twice as close.
I believe the highway toll devices are UHF RFID readers.
Rich, yes, we have a project in the works that'll meet your requirements. Let me summon Joe Grand to talk about it. . .
I had no idea, can't wait to hear more about it!
Yes, I'm currently working on an active RFID system that will complement our existing RFID modules that Parallax manufactures/sells. The product is still in early stages, but I already have proof-of-concept hardware and need to start refining things.
The first products to be released will be the basestation (that will communicate via TTL-level serial to embedded systems/microcontrollers and USB to a PC) and a tag that will simply transmit its unique ID. Future tags may include memory (ala R/W tags), sensors, or capability for the user to hook up external devices. That all remains to be seen, as I'm focused on getting the core design work done. Communication range will be ~10 meters. The tags will run on a single CR2032 coin cell for ~2 years.
We don't have any formal release dates, but probably towards the end of 2013 (much later than the MicroMedic contest). Pricing is undetermined and will depend on final hardware costs, etc.
Hope that helps!
Joe
Are you going to do a build thread like you did on the range finder?
Jim
tae a look at this..
http://www.youtube.com/watch?v=EpCm08ku8HE
??? I discovered many passive tags that can be read over a meter away. The link that mbenitz01 posted is one example. My Good-to-Go pass is another.
If you're willing to use an active tag, the OpenBeacon project has information about using the Nordic nRF24L01+ chips as a transceiver in the active tag.
There is a tradeoff, and some systems manage greater distances with either slower read times or larger tags. Coupling enough energy into a totally passive tag to power it for a fast read is a real problem though beyond half a meter.
Most people don't realize how many tags have batteries in them. For example, all Amtech tags (used by rail cars and all the toll roads in southern Louisiana) are active so that they can be read at high speed as a vehicle moves past the reader. WIth lithium batteries these tags can have a long life, but they do die, more from battery age than from read cycles actually using the chemical energy of the battery.
Does it matter if I want to use them? I was just giving an example of a small, unpowered tag that can be read at long range and at high speed - in response to someone saying that long range and passive tags were mutually exclusive.
Also please note that in post #8 (three months ago) I shared that I had found 125khz readers that would read passive tags at up to two meters - which is four times further away than someone asserted was possible a couple days ago.
Did you get a chance to test the 125kHz readers? Is the two meter figure from your own tests or are citing the documentation?
Edit: If you have a link to the item you purchased, I'd be interested in seeing it.
W9GFO, did the tags work out for you? I'm looking for a reader that will read my 125kHz poultry tags (Chicken tags). You never mention what reader you ended up using I would sure like to know how things turned out. Thanks.
Thanks,
Dave
I actually attempted to order the readers but ran into problems with the seller. I set the project aside for now. The tags are still soaking in saltwater, haven't tested them in a while but I expect that they will still work.