Looking for RFID Module to read key fob at approx 300mm...

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#1
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...without having to re-mortgage the house!

The cheaply available modules (125Khz 20-50 quid) only read about 150mm max.

The next step up seems to be 13.56Mhz long range reader for $500!

I only need to read the tags (writing is not necessary), and it needs serial output to an AVR (so no USB etc)

The budget is about $100 USD, but can go a little higher for the right product.

If anyone knows of anything that might do the job, please let me know.

Thanks in advance!
Pete

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How about making the antenna of the 125kHz larger ?

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Hi, I have tried that (with a CoreRFID ID-2).
It gets better (up to a point), then worse again!

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Who makes the tags? I use HID readers and they work at 125khz. The read range for the unit that is 4x4 inches square is about 4 inches. At 125khz you will not get any better. Most readers are epoxy sealed for enviromental use so extending the antenna will not work as the field generated is a loop antenna inside the epoxy.

If you have more info on the tags I might be able to help you out

Jim

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Hi
The tags are standard EM4002.

Are you saying that 4 inches is the theoretical limit for all 125Khz systems?

I have no problem going with 13Mhz etc - I just need to find one suitably priced.

I can't be the first person who wants to read from a bit further away!

:-)

Thanks
Pete

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Not the first and not the last either.

The 125khz standard was picked because of it's reliability at short range and economics. 4 inches is the theoretical best case for your normal access systems reader. HID mullion readers are the best read range of up to 6 inches open field. Meaning the reader is not mounted to a metal surface. Steed door frames reduce the range by 2-3 inches.

A google search posts 125khz readers that can go up to 35 inches but at a high $$

What is the application that needs this distance?

Jim

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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jgmdesign wrote:

What is the application that needs this distance?

Jim

It's the most important project a man can build - a cat door for the convenience of his fuzzy friends! :-)

I have built one before, with the antenna wound around a tunnel so that when the kitty enters the tunnel, his tag is read and the door opens, but it is very bulky and Mrs. was not super happy with it bolted to the door...

What I would like to do this time is have the antenna as a ramp that the cat walks over, rather than the tunnel system.

This presents another problem, in that the tag is presented at 45 degrees or so to the antenna, not straight on like it was designed for.

So the read distance needs to be basically one cat leg length, + a safety margin to allow for cats arriving off-centre etc., which is why I thought that a read distance of about 300mm should cover it OK.

Thanks!
Pete