PN5180 to Raspberry Pi
Pinout
| PN5180 | Pi |
|---|---|
| 5V | 5V |
| 3.3V | 3.3V |
| RST | GPIO 7 (SPI Chip Select 1) (26) |
| NSS | GPIO 8 (SPI Chip Select 0) (24) |
| MOSI | GPIO 10 (SPI0 MOSI) (19) |
| MISO | GPIO 9 (SPI0 MISO) (21) |
| SCK | GPIO 11 (SPI0 SCLK) (23) |
| BUSY | GPIO 25 (22) |
| GND | GND |
| GPIO | Not Connected |
| IRQ | GPIO 23 (16) |
| AUX | Not Connected |
| REQ | Not Connected |
For reference:
The number at the end of each RPi connection is the physical pin location (the small darker number beside each pin in the diagram below)
(courtesy of pinout.xyz)
Available libraries
- pyPN5180 - https://github.com/fservida/pyPN5180 (uses different pinout) (⚠️Incompatible with the Raspberry Pi 5 due to RP1 chip)
- NXP's Library - https://www.nxp.com/applications/technologies/security/industrial-security/nfc-reader-library-software-support-for-nfc-frontend-solutions:NFC-READER-LIBRARY?tab=In-Depth_Tab (requires free NXP account)
Usage of NXP Library
As of now, the only complete software implementation of the PN5180's feature-set is NXP's in-house library. It supports all cards (with the exception of iClass cards, which do work on the Arduino library, see PN5180 to Arduino and ESP32) and, more importantly, supports card emulation.
⚠️ That said, their latest implementation uses the deprecated sysfs gpio interface, which is slated for removal some time in the near future.
Raspberry Pi configuration
Make sure that SPI is enabled. If it's not, enable it in the raspi-config utility under Interface Options.
Installation
- Unzip
NxpNfcRdLib_PN5180_v07.10.00_Pub.zip - Find out your Raspberry Pi's GPIO offset value if using a Raspberry Pi 2 or above. To do this, run
ls /sys/class/gpio, one of the files/directories should be named gpiochipNUMBER. Said number if your offset value. - Patch
Platform/DAL/boards/Board_PiPn5180.h. This file requires 2 patches.- First, unless you have a Raspberry Pi 1, we need to modify the pin definitions in that file to add the offset value we found out earlier. Simply add the offset values to the pin definitions, for example, for an offset value of 512, the line
#define PHDRIVER_PIN_RESET 16becomes#define PHDRIVER_PIN_RESET 512+16, and so on for the rest of the pins in that definition block. (the code in red is what should be there.) 
- Second, we need to prevent the library from using the obsoleted "bal" driver. To do that, simple uncomment
#define PHDRIVER_LINUX_USER_SPIand comment out#define PHDRIVER_LINUX_KERNEL_SPI. 
- First, unless you have a Raspberry Pi 1, we need to modify the pin definitions in that file to add the offset value we found out earlier. Simply add the offset values to the pin definitions, for example, for an offset value of 512, the line
- After patching
Board_PiPn5180.h, we can finally compile the demos. Make sure that gcc and cmake are installed (sudo apt install them if they aren't). Then in the root folder of the project (theComplianceApp,Examples,NxpNfcRdLiband etc folders should be visible), run the following commands:mkdir _buildcd _buildcmake ..make all
- After everything has (hopefully) compiled, you can run each example binary in
_build/Examples/. A description of each example can be found inAN11802.pdf.
pyPN5180-fork
Our own fork of the pyPN5180 library. Current aim is to re-implement features that are missing from ATrappMann's library.
Issues faced:
Differences between SPI handling between Arduino's SPI library and Linux's spidev (and by extension the python wrapper). SPI transfers deassert chip select between transmissions by default, which is not allowed on the PN5180 (see below). Solution: use xfer2 instead of xfer.
The whole transmit buffer shall be written at once as well. No NSS assertion is allowed during data transfer. PN5180A0XX-C1-C2, page 19