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Interfacing an RFID to a PC — Parallax Forums

Interfacing an RFID to a PC

CruxCrux Posts: 74
edited 2007-04-09 20:31 in BASIC Stamp
Anybody who knows how to interface parallax's RFID Reader to a serial port using MAX232A

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-03-15 19:49
    Crux, due to several requests I will be posting schematics to interface many of our serial devices via RS-232 using the MAX232 chip on Saturday. I won't have a chance before then to do it though. If you can wait until Saturday they will all be posted here on the forums. Take care.

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    Chris Savage
    Parallax Tech Support
  • CruxCrux Posts: 74
    edited 2007-03-19 06:17
    Chris have you posted already the schematics?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-03-19 19:34
    Crux,

    I am just waiting for an issue to be cleared before I post everything to the Completed Projects Forum…Until then here are the ones for the RFID Reader only…I hope these help. Take care.

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    Chris Savage
    Parallax Tech Support
    bmp
    bmp
    PC to RFID [MAX232].bmp
    1M
    bmp
    bmp
    PC to RFID [MAX232_ENABLE].bmp
    1M
    bmp
    bmp
    PC to RFID.bmp
    249K
  • CruxCrux Posts: 74
    edited 2007-03-20 11:52
    Is there really a difference between MAX232 and MAX232A,Im confused..

    I am also planning to interface my BS2 with my PC,does the same style apply?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-03-20 14:19
    Crux,

    There is a difference between the MAX232 and the MAX232A according to the datasheet. The exact part I used was MAX232CPE and I also tried it with the TI MAX232N and both worked. As for the BS2 connections, yes, it is similar. I will be posting complete schematics for all connections within the next two days in the Completed Projects Forum. Today I will post the ones I have that are done. Take care.

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    Chris Savage
    Parallax Tech Support
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-03-20 14:21
    Crux,

    Almost forgot…It looks like (at first glance) that the MAX232A simply uses a different size capacitor. In my schematic replace all 1uF capacitors with .1uF for the MAX232A. Take care.

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    Chris Savage
    Parallax Tech Support
  • CruxCrux Posts: 74
    edited 2007-03-22 11:45
    Chris,

    ····· Just inform me in this forum if the schematics you made is already available.tnx
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-03-22 17:17
    Crux,

    The schematics were posted back a few posts ago...Did you download them? I have more coming for other hardware...Is that what you refer to?

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    Chris Savage
    Parallax Tech Support
  • CruxCrux Posts: 74
    edited 2007-03-24 02:41
    Chris,

    ····· I didnt notice the post but anyway I tried the one that you gave to me.
    I got it running already. Thanks for the help.
  • zach_smithzach_smith Posts: 1
    edited 2007-04-09 20:31
    I used the 'PC to RFID.bmp' schematic to successfully communicate with a simple VB6 program via a serial port, however I don't see the LED switch from red/green/red to indicate that the card was read - it just stays red. If I use the BS2 circuit/program from the Parallax manual it does change color. Is this correct behavior?


    Update: I've realized that the BS2 code is changing the LED. My mistake. Apparently this reader doesn't behave like some other readers I've used.

    Post Edited (zach_smith) : 4/9/2007 9:14:35 PM GMT
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