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RFID Card Readers now shipping from Parallax! — Parallax Forums

RFID Card Readers now shipping from Parallax!

Ken GraceyKen Gracey Posts: 7,387
edited 2005-07-06 16:20 in BASIC Stamp
attachment.php?attachmentid=38108

All backorders have been filled.

Ken Gracey
Parallax, Inc.

Post Edited (Ken Gracey (Parallax)) : 6/23/2005 8:22:02 PM GMT
450 x 373 - 96K

Comments

  • DavidLDavidL Posts: 4
    edited 2005-07-05 18:26
    I just got my backorder in. Thanx.
    I see that the device supports being connected via a 1-wire network?
    Can you share the wiring info and any software related issues to 1-wire implementation?

    If I go with a RS232 wiring instead - I need a TTL to RS232 "adapter"? Do you sell this?

    I want to integrate this hardware with Homeseer home automation software. Any RFID users thinking of this implementation?

    Thanx!
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-07-05 19:29
    The output from the RFID module is straight serial at 2400 baud (TTL, true mode).· You may be able to attach it to your home automation system if you can specify that the system wait for headers before receiving the RFID value as a string of characters.· The attached program demonstrates the RFID module with a BS2.


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    Jon Williams
    Applications Engineer, Parallax

    Post Edited (Jon Williams (Parallax)) : 7/5/2005 7:47:24 PM GMT
  • allanlane5allanlane5 Posts: 3,815
    edited 2005-07-05 19:33
    "Straight serial at 2400 baud" -- and I assume TTL levels, to aid in interfacing.
  • DavidLDavidL Posts: 4
    edited 2005-07-05 20:28
    Jon,
    thank you for the response.
    When the product description says "1-wire" support - do you mean literally one wire or "1-wire" that of Maxim "iButton" type technology?· And if it is the Maxim type definition, then what are suggested wiring and software implementation for usage on the "1-wire" network?

    http://www.maxim-ic.com/1-Wire.cfm

    Post Edited (DavidL) : 7/5/2005 8:33:39 PM GMT
  • Ken GraceyKen Gracey Posts: 7,387
    edited 2005-07-05 20:35
    David,

    Jon's reference to "1-wire" means it uses a single I/O line for bi-directional asynchronous serial communication, not the Maxim communication protocol.

    Sincerely,

    Ken Gracey
    Parallax, Inc.
  • DavidLDavidL Posts: 4
    edited 2005-07-05 20:38
    Dang, because that would really be slick to have multiple RFIDs on a daisy chain wire, along with other "1-wire" devices all speaking to one PC USB or serial port (via "1-wire" interface adapter).
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-07-05 20:39
    No, it's just straight 2400 baud, output only (that's where the 1-wire thing came from) serial. I have sent a note to our web folks to clarify. Sorry for the confusion.

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    Jon Williams
    Applications Engineer, Parallax
  • DavidLDavidL Posts: 4
    edited 2005-07-05 20:44
    So, I am back to serial.
    Do you sell the "TTL compatible UART" or the "RS232 compatible interface by using an external level shifter"? Suggestions on where to buy?
    Is this one?
    http://www.kronosrobotics.com/xcart/customer/product.php?productid=16167
  • allanlane5allanlane5 Posts: 3,815
    edited 2005-07-05 20:44
    Actually, DavidL, making it 'true' one-wire would be a pain in the butt. Then you'd have to either have an advanced BS2p which has native one-wire support, or add an additional one-wire chip. And THEN you'd have to support the addressing modes of one-wire to tell one of the daisy-chained devices that you want to listen to it.

    The BS2 can support up to 16 RS-232 lines (one at a time), so dedicating ONE pin to the RFID device is a cheap price to pay for the simplicity of interfacing.
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-07-06 12:58
    If you're using our BOE we have an RS-232 DCE AppMod (http://www.parallax.com/detail.asp?product_id=29120).· I've also used Al Williams' RS-1 (http://www.awce.com/rs1.htm).
    DavidL said...
    So, I am back to serial.
    Do you sell the "TTL compatible UART" or the "RS232 compatible interface by using an external level shifter"? Suggestions on where to buy?
    Is this one?
    http://www.kronosrobotics.com/xcart/customer/product.php?productid=16167
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    Jon Williams
    Applications Engineer, Parallax
  • allanlane5allanlane5 Posts: 3,815
    edited 2005-07-06 16:15
    Oh, for heaven's sake, the BS2's SERIN command IS a "TTL Compatible UART", and it will work on 16 possible pins.

    The beauty of the RFID tag is that you can hang multiples off a BS2.

    Oh, it just hit me that you're trying to apply this WITHOUT a BS2, aren't you?

    In that case, that Kronos part you call out above (I didn't go there, but I know he makes a nice one for a reasonable price) is probably what you want.

    Yup, just checked (and edited this post) and that's definitely what you want.· $10.00 is a really nice price, too.
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-07-06 16:20
    The output from our RFID reader is text-based so that it can be used directly (with a level shifer) a PC-type terminal. You can also connect it directly to the new Parallax serial LCD since it behaves like a terminal too.

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    Jon Williams
    Applications Engineer, Parallax
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