SparkFun Forums

[Dakine]

Hey all,

I'm looking for some clarity on the type of RFID I should pursue for a project. I need a passive RFID that will give me a 2-3 foot read range.

I have not determined my power source yet, but it will be a Li-Ion battery of some sort. For now, I'll be using wall power, but I'll likely switch to an 18650.

Size wise, I'm hoping the antenna can stay under 1.5 inch x 2 inch.

Nothing like some simple constraints right?

I went ahead and purchased the SM130 and eval shield and only after I soldered them together did I discover the range is closer to one inch than one foot. Based on what I'd read about higher frequencies having longer read distances, I thought it was a better choice than the ID-12LA (Which only has a 120mm range).

Anyhow, if you have any suggestions as to which technology I could pursue, it would be much appreciated. Or if this is impossible, it'd be good to know that too!

Thanks,
Chris

[stevech]

Not so much the freq, but that the tags are passive and thus short range.
Sounds like you need to do more reading and research before choosing.

There are few passive RFIDs that have more than 3 or so inch read range. Takes quite a bit of power to do so.
You can go to the read-only passive tags and get 12-18in or so. For just a serial number.
But this is the research you need to do for the assignment.

[Dakine]

Good point, I should have added that I only need read-only.

That's one of the reasons for the post, I've read articles stating 3-6 feet for passive range, yet I can't find a reader with any range listed over an inch or two.

[stevech]

There aren't many passive RFID tags with 1 ft or more read range. I used some way back; the principle was a reader with relatively high power via a patch antenna in 2.4GHz (like you see in WiFi). It was long ago, from Micron.

Have you read the ads, articles and history of
http://www.rfidjournal.com/

[Dakine]

No, that is a new link for me. I will check it out. Thanks!

In the meantime my partner on the project has convinced me that BLE might be a simpler option for us. I'll be looking into that, as well. My initial thought is it's overkill but it does seem to remove some of the complexities facing us currently.

[stevech]

BLE is not RFID!

Can you reinterpret RFID to be Near Field Communications (NFC) ? It's an ISO standard.
75 cent RFID tags with memory.
My HTC one and most new cell phones nave an NFC reader built in. I have NFC tags, size of a quarter, adhesive. I stuck some on the tops of wine collection in cold storage bottles. My phone will interrogate, read, lookup photo of wine bottle label, lookup in Evernote as a database. No code.

But NFC is 1 inch or less. Arguably not RF.

Some tags use inductive fields, not efields and in RF. Cheapest.

[Dakine]

Agreed - That's why I presented it as an alternative to the passive RFID I was hoping to find.

[stevech]

Ooops... crossing post updates