two extension board wiring

HI Hunszasz,

I'm afraid that the software cannot handle two boards at the same time.

May I ask you what you are planning to do with two NFC boards at the same time?

Regards,

Michael

Hi Michael,

I working on an entrance system.Other word, I want to store the in- and outgoing traffic with rfid tags.

Do you see a chance to develop multi SPI feature api in near future?

Best regards,

hunszasz

Hi Hunszasz,

I understand your use case now. Usually such systems are done with embedded readers which are connected to any back end. Such system could consist of the following system:

LPC1769 [1] + EXPLORE-NFC

Where the EXPLORE-NFC is connected to the LPC1769 via SPI or I2C and the LPC1769 is connected via USB or Ethernet to the back end. Where the back end could be the Raspberry Pi.

However, this might require a bit too much effort for a private project. What you could do is, to connect two EXPLORE-NFC to different interfaces on the Raspberry Pi. One to the I2C interface, the other one to the SPI interface.

You could then simply create two applications for the Raspberry pi running in the background. One operating the EXPLORE-NFC on the I2C interface, the other one on the SPI interface.

With that method you don't need to take care about arbitration.

Regards,

Michael

[1] uk.farnell.com/nxp/om13000-598/evaluation-board-lpc1769-lpcxpresso/dp/2251815

Hi Michael,

Thank you so much!

Yes, it is a realizable solution that connect two EXPLORE-NFC to raspberry pi via diffrent interface.

I will create some code for do that, I will let you know the results.

Best regards,

hunszasz

Hi Michael,

There is a little problem in above realization, because in EXPLORE NFC feature list[1] there is a row:

"Flexible interface selection (SPI or I²C), software currently supports SPI"

So the question is how can I connect to EXPLORE NFC board via I2C?

Thank you for your answer in advance.

Best regards,

hunszasz

[1]EXPLORE-NFC

Hi,

the reason that only SPI is officially supported is, that the connection in the BAL (Bus Abstraction Layer) is only interfacing with the SPI exchange functions provided by the WiringPi library. You'd have to enhance this BAL to interface with the I2C interface. Two files are required to be changed:

nxprdlib\comps\phbalReg\src\phbalReg.c

and

nxprdlib\comps\phbalReg\src\phBalReg_RpiSpi.c

Additionally you'd have to change the 0 Ohm resistors like indicated on the EXPLORE-NFC from SPI to I2C. For more detailed info please consult the schematics.

Regards,

Michael