I have been busy with this RFID in these two days. First of all, I admit that I am a rookie, the platform is based on the 51 single-chip microcomputer introduced by beginners, but I still summarize the recent gain of the code.
Software design of card reader: Look at the PDF document seems to have been given, but beginners, understanding is also a long time, here I suggest the design process in Datasheet, in combination with code analysis, to achieve the effect of identifying the card.
The first thing is to be a reset answer. According to Datasheet, the communication protocol of the MIFARE RF card and the baud rate of communication are defined. When the card enters the card reader, the card reader will be specific. The agreement communicates with him, and it is judged whether the entry card is Mifare RF card
In fact, Datasheet seems to be very hanging, but in fact, it is actually a feeling that can't touch the mind. In fact, I read the code, I know that the software on the software is initialized, and the card reader is going once. Software reset, and set the method of working card reader
The code here is:
PCDReset (); // RC522 initialization
PCDANTENNAOFF (); // Close antenna
PCDANTENNAON (); // Open antenna
M500pcdconfigisotype ('a'); // Setting working mode
The second step is to prevent conflict, in DataSheet: When there are multiple cards entering the sensing range of the card reader, the anti-conflict mechanism will start, automatically operate from multiple cards, then there is a lot of words, speak How to prevent conflict
In fact, personal feelings is still important, because not reading card, where to prevent conflict, in fact, anti-conflict speaking so much implementation is a function
Status = pcdRequest (PICC_REQALL, G_UCTEMPBUF);
// picc_reqall he is a macro definition means looking for all cards in the antenna,
// g_uctempbuf is an array where the first two digits in the card here are placed in arrays.
Status = pcdanticoll (g_uctempbuf); / / Anti-conflict
It is a bit more meaning that sometimes it is necessary to implement the type of judgment card. There is a fragment here, you should use the program.
Judgment the type of card, judge the first data returned when the card is read, and other functions are 12864, you don't have to go further.
// Is there a card, judge what card, then display it on the LCD
// 0x4400 = mifare_ultralight
// 0x0400 = mifare_one (S50)
// 0x0200 = mifare_one (S70)
// 0x0800 = mifare_pro (x)
// 0x4403 = Mifare_Desfire
Switch (g_uctempbuf [0])
{
Case 0x44:
CK12864_COM (0x93);
For (i = 0; I<10; i ++)
{
CK12864_Data (leiXing1 [i]);
}
Break;
Case 0x02:
CK12864_COM (0x93);
For (i = 0; I<8; i ++)
{
CK12864_DATA (leiXing2 [i]);
}
Break;
Case 0x04:
CK12864_COM (0x93);
For (i = 0; I<8; i ++)
{
CK12864_DATA (leiXing3 [i]);
}
Break;
Case 0x08:
CK12864_COM (0x93);
For (i = 0; I<6; i ++)
{
CK12864_DATA (leiXing4 [i]);
}
Break;
}
Next is the process 3, select the card, operate on the card, according to Datasheet, the sequence code of the selected card, and return to the card at the same time:
Code implementation:
Status = pcdselect (g_uctempbuf);
Process 4, that is, the selection card is operated, first verify the password, including read and write operations
The implementation of the code is also two sentences:
Status = pcdauthState (PICC_AUTHENT1A, 5, DefaultKey, g_uctempbuf);
IF (status! = mi_ok)
{Continue;
// Write data to block
Status = PCDWRITE (5, DATA1);
IF (status! = mi_ok)
{Continue;
// Read a piece of data
Process 5: Intention to sleep:
PCDHALT ();
This 5 steps can realize the specific operation of the card, now we can control stepper motors by credit card, actually omitted step 4
If you do an unnamed credit card, that is, there is no opening door that is bound to a specific card number, now you can implement it.
Sample code:
#include
#include "mian.h"
#include "rc522.h"
Typedef unsigned int uint
Typedef unsigned char uchar;
Uchar status;
Uchar g_uctempbuf [20];
void main ()
{
UINT I;
// Initialization:
PCDReset (); // RC522 initialization
PCDANTENNAOFF (); // Close and open antenna
PCDANTENNAON ();
M500pcdconfigisotype ('a'); // Setting working mode
/ / Anti-conflict, where a loop is required, let the card reader continue to read the card
While (1)
{
Status = pcdRequest (PICC_REQALL, G_UCTEMPBUF);
// picc_reqall he is a macro definition means looking for all cards in the antenna,
// g_uctempbuf is an array where the first two digits in the card here are placed in arrays.
IF (status! = mi_ok) // No card is found, continue to execute pcdRequest ()
{
CONTINUE;
}
Status = pcdanticoll (g_uctempbuf); / / Anti-conflict
// Card sequence number, 4 bytes, the status here can determine the implementation of PCDanticoll
// If the execution is successful, it means that the g_uctempbuf has been remembered in the only card number.
// Here G_UCTEMPBUF has used 2 + 4
IF (status! = mi_ok) // No card is found, continue to execute pcdRequest ()
{
CONTINUE;
}
PCDHALT ();
IF (status == mi_ok)
{
LED_GREEN = 0;
For (i = 0; I<125; i ++)
{
Step ();
}
LED_GREEN = 1;
}
}
}
Void delayms (unsigned int _ms)
{
TH1 = (unsigned char) (RCAP2_1MS>>8);
TL1 = (unsigned char) (RCAP2_1MS);
ET1 = 0; // disable timer2 interrupt
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