Rfid mfrc522

[flotulopex]

Anyone did this?

[flotulopex]

Hi,

I might need a little help here - I'm stuck for hours now.

It's the first time for me to use this RFID module and it is giving me some headache.

For a test, I want to read the first three bytes of the tag's ID and print them serially out.

But up to now, I can't make the RFID module "read" something. I'm not sure about my connections and about the different timings and whatever I have to do to "start" the read process.

Does anyone have a good idea to get me started reading some data?

My test project:


The RFID module I'm using is this one for ARDUINO and the connections I used:


Here's is my current code:

' ====== FUSES =====================================================================================
' PIC 16F690 Fuses (MPASM)
@ __config _FCMEN_OFF &_IESO_OFF &_CPD_OFF &_WDT_OFF &_HS_OSC &_BOR_OFF &_CP_OFF &_PWRTE_OFF &_MCLRE_OFF

' ====== REGISTERS =================================================================================
'             76543210
OPTION_REG = %10000000 ' Pull-Ups OFF
OSCCON     = %00000000 ' Internal RC
ANSEL      = %00000000 ' Select analog inputs Channels 0 to 7
ANSELH     = %00000000 ' Select analog inputs Channels 8 to 11
WPUA       = %00000000 ' Select weak pull-ups
WPUB       = %00000000 ' Select weak pull-ups
ADCON0     = %00000000 ' Select the VP6 channel as ADC input bits5:2 (xx1101xx)
ADCON1     = %00000000 ' Set FRC
VRCON      = %00000000 ' VP6 reference
CM1CON0    = %00000000 ' Comparator1 Module
CM2CON0    = %00000000 ' Comparator2 Module
INTCON     = %00000000 ' INTerrupts CONtrol; GIE=1, T0IE=1
TRISA      = %00000000 ' Select Input/Output (0 to 5)
PORTA      = %00000000 ' Set High/Low (0 to 5)
TRISB      = %00000000 ' Select Input/Output (4 to 7)
PORTB      = %00100000 ' Set High/Low (4 to 7)
TRISC      = %00000000 ' Select Input/Output (0 to 7)
PORTC      = %00000000 ' Set High/Low (0 to 7)

' ====== DEFINES ===================================================================================
define OSC 4

' ====== VARIABLES & CONSTANTS =====================================================================
SPI_SCK     Var PORTB.4 ' SCK (SPI Clock)
SPI_MISO    Var PORTB.5 ' MISO (master In, Slave Out)
SPI_NSS     VAR PORTB.6 ' "NOT" Slave Select (SDA pin of module RC522)
LED         var PORTB.7
Serial_Out  VAR PORTC.7

SPI_Mode    var byte
RFIDData    Var byte(10)
Serial_Bdr  VAR word
Counter     var word

' ====== INITIALIZE ================================================================================
INIT:
Serial_Out  = 1 ' to avoid garbage serial data
Counter     = 0
SPI_NSS     = 1
SPI_Mode    = 0 ' MSBPRE
RFIDData    = 0
Serial_Bdr  = 84 '9600DTN

' ====== PROGRAM ===================================================================================
MAIN:
    ' Read RFID tag
    SPI_NSS = 0 ' select the RFID reader
    PAUSEus 50
    Shiftin SPI_MISO, SPI_SCK, SPI_Mode, [RFIDData(0),RFIDData(1),RFIDData(2)]
    SPI_NSS = 1 ' deselect the RFID reader
    
    ' Printout RFID data
    Counter = Counter + 1
    serout2 Serial_Out, Serial_Bdr,[DEC5(Counter), " ",DEC(RFIDData[0]),DEC(RFIDData[1]),DEC(RFIDData[2]),13,10]
    
    ' Alive witness
    TOGGLE LED 
    
    Pause 500
    Goto main:
 
End

'======= CIRCUITRY =================================================================================
'PORTA.0[19] ICSPDAT                  VDD >01-20< VSS/GND
'PORTA.1[18] ICSPCLK             OSC1/RA5 |02-19| RA0/AN0/DAT
'PORTA.2[17]                 AN3/OSC2/RA4 |03-18| RA1/AN1/CLK
'PORTA.3[04] MCLR                MCLR/RA3 >04-17| RA2/AN2
'PORTA.4[03] OSC2 - Xtal         CCP1/RC5 |05-16| RC0/AN4
'PORTA.5[02] OSC1 - Xtal          P1B/RC4 |06-15| RC1/AN5
'                             AN7/P1C/RC3 |07-14| RC2/AN6
'PORTB.4[13] SPI_SCK              AN8/RC6 |08-13| RB4/AN10
'PORTB.5[12] SPI_MISO             AN9/RC7 |09-12| RB5/AN11
'PORTB.6[11] SPI_NSS                  RB7 |10-11| RB6
'PORTB.7[10] LED
'
'PORTC.0[16]
'PORTC.1[15]
'PORTC.2[14]
'PORTC.3[07]
'PORTC.4[06]
'PORTC.5[05]
'PORTC.6[08]

[HenrikOlsson]

Hi Roger,
I'm confused, where do you see that shifiting in three bytes like that should give you the three first byte of a cards S/N number?

It looks to me as if the RFID reader chip implements a "proper" SPI slave meaning you have to shift data out at the same time as you shift data in. If that's the case SHIFTIN/SHIFTOUT won't work because it can only shift data out OR shift data in, it can't do it simultanously.

/Henrik.

[flotulopex]

Henrik,

I'm confused, where do you see that shifiting in three bytes like that should give you the three first byte of a cards S/N number?

That's the point; I'm maybe even more confused than you are

Honestly, I don't know how to handle the card reader so I need some "theory" on how it works so I will be able to start thinking the right way.

[richard]

Here's a start. it reads and writes to the mfrc522.registers using the ssp module
I have made a demo for a 16f690 that loads up the regs [settings like in the Arduino demos ]
and reads them back. that bit is easy
I have not discovered how to read a card yet, the Arduino and python libs I have tried to
digest have code that's so obscure it leave me cold .

Arduino seems to poll CommIrqReg looking for a value of 0x45 [I think] but I have same regs set
but the card seems to be ignored , I'm just guessing how it works the reg never changes for me

reg printout for regs 1 to 3f

01,20 02,80 03,00 04,15 05,00 06,00 07,21 08,00
09,00 0A,00 0B,08 0C,10 0D,00 0E,A0 0F,00
10,00 11,3D 12,00 13,00 14,83 15,40 16,10
17,84 18,84 19,4D 1A,00 1B,00 1C,62 1D,00
1E,00 1F,EB 20,00 21,FF 22,FF 23,88 24,26
25,87 26,48 27,88 28,20 29,20 2A,8D 2B,A9
2C,00 2D,E8 2E,00 2F,00 30,00 31,00 32,00
33,80 34,00 35,00 36,40 37,92 38,00 39,00
3A,00 3B,88 3C,FF 3D,00 3E,03 3F,00

[HenrikOlsson]

Yeah, what we're dealing with here is not the interface to a "RFID-reader" but to the complete "RFID-radio". I have not looked at any example code for other platforms but I would expect it to be a fairly complicated setup procedure, configuring all the registers etc - and even more so KNOWING what to configure them with. And when Richard says HE cringes when looking at the code for it I don't think I'll even bother :-)

There are readers available implementing both the "radio" and a microcontroller giving you an interface to "just" the card and not the complete "radio" tranceiver - much easier but a bit more expensive. One example is the OEM/MIFARE ICODE board from IBTechnology (datasheet) which I've personally used with success.

[flotulopex]

Here's a start.

Thanks a lot Richard. But as you say, this is only a part of the problem...

Since I don't need nor want to go for rocket science, I'll take Henrik's advice and find a "plug'n play" reader

[flotulopex]

...the OEM/MIFARE ICODE board from IBTechnology which I've personally used with success.

Hi Henrik,

I received my reader from IBTechnology a few days ago and I'm still stuck with even reading a tag. I must be overseeing something basic

Would you have snippet of code or even just some serial commands as a start for me please?