Can I tell when chip/card has left vicinity of RFID sensor?

Technical Discussion on the PhidgetRFID
trhaynes
Fresh meat
Posts: 2
Joined: Sun Mar 02, 2014 8:28 am
Contact:

Can I tell when chip/card has left vicinity of RFID sensor?

Postby trhaynes » Sun Mar 02, 2014 8:34 am

I have an idea for a little hardware project and I'm eyeing the Phidgets USB RFID reader (hooked up to a Raspberry Pi). I need to know when a RFID chip/card is in range of the sensor, which is easy to do. But the chip will stay near the sensor (for minutes or 2-3 hours), and I need to know that. And then I need to know when the chip moves out of range, so I can preform another action.

Basically, does the Phidgets USB RFID reader continuously send the chip ID via USB when the card is in range, or does it do some sort of debouncing in hardware?

If RFID isn't designed for this, can anyone suggest another inexpensive NFC-ish scheme that might work?

Thanks for your help!

-tom


ps. The idea is to make a music box ... an album starts playing when you place the "album" (block w/chip) onto a basic wooden board (w/tech inside). Then it stops when you move the block off again.

User avatar
mparadis
Site Admin
Posts: 656
Joined: Fri Oct 28, 2011 12:17 pm
Contact:

Re: Can I tell when chip/card has left vicinity of RFID sens

Postby mparadis » Mon Mar 03, 2014 8:37 am

There's an event called OnTagLost or TagLost depending on the language you're using. Take a look at the RFID class in the API for your language for more information.

trhaynes
Fresh meat
Posts: 2
Joined: Sun Mar 02, 2014 8:28 am
Contact:

Re: Can I tell when chip/card has left vicinity of RFID sens

Postby trhaynes » Mon Mar 03, 2014 10:15 am

Great, thank you. Looks like there's a setOnTagLostHandler() method in Python.

What is the "refresh rate" for the sensor? That is, how quickly will my code be alerted that the tag was lost?

Thanks.

User avatar
Patrick
Lead Developer
Posts: 3099
Joined: Mon Jun 20, 2005 8:46 am
Location: Canada
Contact:

Re: Can I tell when chip/card has left vicinity of RFID sens

Postby Patrick » Mon Mar 03, 2014 12:37 pm

You will get the tagLost event about 200ms after the tag is removed.

-Patrick


Return to “RFID”

Who is online

Users browsing this forum: No registered users and 1 guest