Designer needs electronics help!

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simbob
 
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Designer needs electronics help!

Post by simbob »

I am a Product Design Post Grad student looking for some advice, i've arrived at your door through recommendation.

I am currently working on a project which i want to use NFC technology and wondered if you may be able to advise me on what type of chips & tags i would need to achieve what i want to do - and if it's possible.

What I want to achieve is; a chip that would sense the presence of the tag up to a metre or two away and illuminate an LED on the (powered) chip component, but then switch off the LED on contact (likewise the LED will switch off when beyond the proximity radius), is this possible with NFC? and would it be possible with one chip & tag circuit or two separate circuits? Can you advise how i might do this and if you sell the components i would need.

Also (maybe theoretically), would be possible to fit what i am asking into something approximately the size of a diving watch?

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adafruit_support_bill
 
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Re: Designer needs electronics help!

Post by adafruit_support_bill »

NFC is typically limited to a range of a few centimeters. RFID tags can operate over several meters with the right equipment. RFID tags can be quite small. But to detect and activate them from 1 meter requires a fairly large and powerful antenna. The NFC/RFID board that we sell will work over a range of a few centimeters.

https://www.adafruit.com/search?q=nfc

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simbob
 
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Re: Designer needs electronics help!

Post by simbob »

thanks Bill, a couple of further questions; when you say "fairly large and powerful antenna" can you give me an idea of the sort of sizes we would be looking at if it were a product? Is it therefore RFID i need to be looking at rather than NFC?

Also, is the PN532 NFC/RFID controller breakout board the smallest one you have? what is used in mobile phones?

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adafruit_support_bill
 
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Re: Designer needs electronics help!

Post by adafruit_support_bill »

Passive RFID tags have no power source of their own. They get their power through the air from the RFID antenna. To broadcast that power over longer distances you need more power and/or a directional antenna that can focus the beam on a narrow area. This 12" square reader can detect tags up to 2 meters away: http://www.hidglobal.com/products/reade ... imity/5375

With active RFID tags, the tags have their own power source, so they can have a much longer range. We do not have any active RFID products in the store.

The PN532 board uses The same chip as in some phones. The antenna on NFC enabled phones is similar in size to the one on the shield.

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