RC522 interface with PIC16F887a

EuniceLing · Joined: 12 Apr 2015 Posts: 3

hi everyone, can i directly interface RC522 with PIC16F887a? Is MAX232 needed?

dyeatman · Joined: 06 Sep 2003 Posts: 1933 Location: Norman, OK

The RC522 is 3.3v. The answer is yes if the 887a is run at 3.3V.
If you read the RC522 datasheet you will find it uses an SPI interface, NOT RS232.
However the 887a cannot be run at full speed (20MHZ) while at 3.3V (read the 877a datasheet for more info)
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asmboy · Joined: 20 Nov 2007 Posts: 2128 Location: albany ny

consider pic LF parts or 18fxxKxx family for better perfomance at 3v..

EuniceLing · Joined: 12 Apr 2015 Posts: 3

So what should I do now ? Pic18f45k22 can directly interface with mfrc522 ?

Ttelmah · Joined: 11 Mar 2010 Posts: 19499

You write a driver.

You get the data sheet. You make the SPI connections to the PIC's SPI connections (remember the DO line on the PIC goes to the DI line on the 522, and vice versa). You work out from the data sheet which SPI mode the chip uses, and setup the PIC's SPI to use this mode. Then you get it so you can read and write to the registers on the chip, and then set it up to do what you want.

Step by step.

Get the chip working first.
Have it setup so you can talk to it with something line RS232, makes debugging a lot easier.
Then setup the SPI, etc. etc..

liusse · Joined: 26 Apr 2015 Posts: 3 Location: Spain

EuniceLing · Joined: 12 Apr 2015 Posts: 3

Hi liusse,
can you provide me the code? i can't download it from the website provided.

Thanks

liusse · Joined: 26 Apr 2015 Posts: 3 Location: Spain