0

Conect multiples PN532 NFC/RFID Shields
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Conect multiples PN532 NFC/RFID Shields

by didelco on Fri May 10, 2013 11:11 am

Hi !

It is posible connect multiple NFC Shields to an arduino or multiple arduinos using I2C?
It is posible change the I2C address of the NFC Chip?

I have no much experience with I2C.

Thanks!!!
didelco
 
Posts: 1
Joined: Fri May 10, 2013 11:06 am

Re: Conect multiples PN532 NFC/RFID Shields

by adafruit_support_bill on Fri May 10, 2013 12:02 pm

The i2c address on the pn532 is fixed at 0x48. But it may be possible to talk to more than one if you use software i2c on another set of pins.

adafruit_support_bill
 
Posts: 75725
Joined: Sat Feb 07, 2009 10:11 am

Re: Conect multiples PN532 NFC/RFID Shields

by kapcom01 on Wed Jul 24, 2013 8:27 pm

How about connecting multiple pn532 breakout boards to Raspberry Pi?
I think is a little harder to use software i2c on other gpio.. Isn't there any way to change the pn532's address?

kapcom01
 
Posts: 3
Joined: Wed Jul 24, 2013 8:24 pm

Re: Conect multiples PN532 NFC/RFID Shields

by adafruit_support_bill on Wed Jul 24, 2013 8:40 pm

It may be possible using a board with multiple i2c buses like the RasPi or the Arduino Due.
I don't think you can change the address of the pn532.

adafruit_support_bill
 
Posts: 75725
Joined: Sat Feb 07, 2009 10:11 am

Re: Conect multiples PN532 NFC/RFID Shields

by akirillov on Fri Sep 21, 2018 4:55 pm

The PN532 chip itself supports I2C address setting via SFR register "I2CADR" (register address DBh)
Someone just should implement PN532_COMMAND_WRITEREGISTER in the library, or may be higher level function just to set the address.


Answering to myself DBh SFR, which contains I2C address is not accessible over comm interface.
Only a very limited set of SFRs is available for reading/writing with ReadRegister/WriteRegister commands.

Replacing PN532's firmware (if it is a flash rom and not a mask rom inside),
patched with required new I2C address or functionality to change it - is way outside of this forum's topic :)

akirillov
 
Posts: 1
Joined: Fri Sep 21, 2018 3:28 pm

Please be positive and constructive with your questions and comments.