RFID Reader - Card reliability??

Steve Jones

Hi,

I've been working on an RFID based garage door opener.. It's been working great (in it's "half done" state) for about a year now, but now all of a sudden, within 2 weeks, TWO of my four RFID fobs have stopped working...

I'm using the serial reader (old read-only one) and these keychain fobs (item 28161)

Admittedly, they get banged around a bit, between being in my pocket or my wife's purse, but they look physically fine. Has anyone else had any problems with reliability on these RFID FOBs? I bought 20 of them, and I guess they're cheap enough to consider disposable, but I do like to KNOW that I'm going to get in the house!!

-Steve

Franklin

When you try them do the register but don't read correctly or not register at all? Have you tried any of your other fobs? Undamaged I don't see anything that could fail.

sfenwick76

Steve,

I have noticed the same issue. I built an RFID-based toy for my daughter. It has worked great for about 5 months, now the tags only respond maybe 10% of the time if I am lucky. I tried other tags. I bought 20 of these tags

http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/rfid/List/0/SortField/4/ProductID/427/Default.aspx

And they are all acting flaky now. Even the sample tags that came with the unit are flaky. I am thinking maybe it is the reader itself? It is very frustrating.

Stephen

Steve Jones wrote: »

Hi,

I've been working on an RFID based garage door opener.. It's been working great (in it's "half done" state) for about a year now, but now all of a sudden, within 2 weeks, TWO of my four RFID fobs have stopped working...

I'm using the serial reader (old read-only one) and these keychain fobs (item 28161)

Admittedly, they get banged around a bit, between being in my pocket or my wife's purse, but they look physically fine. Has anyone else had any problems with reliability on these RFID FOBs? I bought 20 of them, and I guess they're cheap enough to consider disposable, but I do like to KNOW that I'm going to get in the house!!

-Steve

sfenwick76

Ok, I figured out what the problem is. The voltage going to the reader was too low! (Because the batteries needed replacing!) My voltage regulators in the toy are set up strange so that the voltage delivered to the RFID reader droops before other voltages in the system.

So, the first thing I would check is that 5VDC is being delivered to the RFID reader. I reproduced the problem by connecting the RFID reader to a bench supply at ~3.8VDC, and the reader started acting flaky again.