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HELP WITH RFID Card Reader Serial 28140 ?? — Parallax Forums

HELP WITH RFID Card Reader Serial 28140 ??

dodedode Posts: 1
edited 2013-04-12 08:08 in Learn with BlocklyProp
how i connect RFID Card Reader Serial 28140 to microcontroller pic16f877a ??? please tell me in detail how i can read tags !!
one other thing i need if anyone have the code for the rfid in mikroc language plz give it to me

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2012-10-08 12:39
    This is a Parallax support forum. We can give you general advice about hooking up Parallax sensors to other company's microcontrollers, but can't help you with detailed microcontroller-specific information except for Parallax microcontrollers like the Stamps or the Propeller for which there are examples on the RFID Reader product webpage.

    The Serial RFID Reader has a serial output and an enable input line. You have to provide +5V and ground (0V) power to the Reader and the enable line has to be high (+5V) when the RFID Reader is inactive and low (0V) when you want the Reader to be active. When active and when an RFID card is present, the RFID Reader will continuously provide standard 8-bit serial data at 2400 Baud on its output pin. This output is idle at +5V (1 bits) and goes to 0V (0 bits) as needed. Any 5V compatible microcontroller can receive this using either built-in hardware or serial input software. We can't help you with this part. You'll have to go to the Microchip support website for sample code and suggestions.
  • mgi_elmajbriemgi_elmajbrie Posts: 1
    edited 2012-10-25 11:34
    dode wrote: »
    how i connect RFID Card Reader Serial 28140 to microcontroller pic16f877a ??? please tell me in detail how i can read tags !!
    one other thing i need if anyone have the code for the rfid in mikroc language plz give it to me

    I have programmed pic16f877a controller to work with 28140 RFID card reader. it is compatible with Microchip controllers. But, the code I created was in MikroBasic. If that would be useful for you, plz let me know.
  • lllerenalllerena Posts: 1
    edited 2013-04-12 03:51
    May i ask you how did you connect the 28140 (5 Volts) with the pic? I need to do the same but with the propeller (3.3V) , but i cant find a schematic. I know it is simple, but is there any suggestion?
    Regards,
    Luis Llerena A.
  • Mike GreenMike Green Posts: 23,101
    edited 2013-04-12 08:08
    Here is a Spin program from the Propeller Object Exchange to use with the RFID reader. The comments at the beginning of the program describe very briefly how to connect the two. They talk about using a 1K resistor between the RFID reader's SOUT and one Propeller I/O pin. I'd use a 3.3K resistor instead. This protects the "protective diode" on the chip from too much current. The diode is rated at 500uA and there's roughly a 1.64V difference between the RFID reader's output and the maximum voltage on a Propeller pin (R = E / I = 1.64V / 0.0005A = 3.3K. You can directly connect another Propeller I/O pin to the RFID reader's /ENABLE since that's an input for the RFID reader.
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