UM2548: provide more details about connecting X-NUCLEO-NFC08A1 directly to Raspberry Pi

[ThomasM]

I´d also like to connect the X-NUCLEO-NFC08A1 to a Raspberry Pi 3 or 4 but want to avoid using an ARPI600. The fact that you either need to 

fix a hardware pin of the X-NUCLEO-NFC08A1 board or the ARPI600 makes me feel that you are not a big fan of this device, too.

While I already found some questions here (see links below, is there more?) related to how to connect the board to the Pi pins the information is rather 

fuzzy to me. I especially miss an easy overview of the mapping of X-NUCLEO-NFC08A1 pins to Pi pins as they are configured by default in the driver.

How about extending UM2548 by a chapter that explains this direct connection (and if required adaptations in the driver) in detail - 

I could imagine that would help a lot of people to get started quickly!

Thanks and best regards,

Thomas

[1] /question/0D53W00000vP4ulSAC/linux-demo-xnucleonfc06a1-canot-find-device

[2] /question/0D53W00001onuH0SAI/xnucleonfc06a1-connections-to-raspberry-pi

[Brian TIDAL]

Hi,

I would personally not recommend direct connection through wire jumpers as this is usually not so reliable vs. using an interposer board. Make sure to use short cables and make sure to have the cables outside the RF operating volume.

Anyway, most of pin mapping is described in the rfal_platform.h:

X-NUCLEO-NFC06 GPIO/LEDs configuration
 IRQ_MCU PA0 A0 = CN8.1
 MCU_LED1 PA1 A1 = CN8.2
 MCU_LED2 PA4 A2 = CN8.3
 MCU_LED3 PB0 A3 = CN8.4
 MCU_LED4 PC1 A4 = CN8.5
 MCU_LED5 PC0 A5 = CN8.6
 MCU_LED6 PA8 D7 = CN9.8
 
 Jumpers on the Waveshare ARPI600 remaps CN8 connector as follow:
 A0 = CE1
 A1 = P21
 A2 = P22
 A3 = P23
 A4 = P24
 A5 = P25
 
 D7 = P5
 
 According to the ARPI600 MCU/Pi connector mapping:
 CE1 = 7 (IRQ_MCU)
 P21 = 5 (MCU_LED1 = LED F)
 P22 = 6 (MCU_LED2 = LED B)
 P23 = 13 (MCU_LED3 = LED A)
 P24 = 19 (MCU_LED4 = LED V)
 P25 = 26 (MCU_LED5 = LED AP2P)
 P5 = 24 (MCU_LED6 = TX)

i.e. CN8.1 (IRQ_MCU) is connected to GPIO07 of the RPi 3/4 (which is actually Pin 26 of the RPI).

SPI is connected on spi0 which is:

CN5.6 <--> SPI0_SCLK/GPIO11 (pin 23)

CN5.5 <--> SPI0_MISO/GPIO09 (pin 21)

CN5.4 <--> SPI0_MOSI/GPIO10 (pin 19)

CN5.3 <--> SPI0_CS0(RPi3) or SPI0_CE0(Rpi4)/GPIO08 (Pin 24)

Rgds

BT