View source for PN532 NFC Module for Raspberry Pi

=='''Premise'''==
Note: If you have configured libnfc before, please delete the config file. 
<pre>
 sudo rm -rf /etc/nfc
</pre>

=='''Introduction'''== 
Raspberry Pi PN532 NFC module, as its name implies, is based on PN532 chip and used to 13.56 MHz near field communication. This module is equipped with on-board antenna, so there is no external antenna coil. It is compatible with SPI, IIC interfaces to communicate. With the support of NFC library, Raspberry Pi can connect products with the function of NFC, thus it is easy to use. <br>
[[File:PN532.jpg]]<br>

=='''I2C Communication Instructions for Raspberry Pi'''==
'''1. Open I2C of the Raspberry Pi : '''
 sudo raspi-config
Select '''5 Interfacing Options''' -> '''I2C''' ->''' yes'''.<br>
'''2. Install some dependent packages'''
 sudo apt-get update
 sudo apt-get install libusb-dev libpcsclite-dev i2c-tools
'''3. Download and unzip the source code package of libnfc'''
 cd ~
 wget http://dl.bintray.com/nfc-tools/sources/libnfc-1.7.1.tar.bz2
 tar -xf libnfc-1.7.1.tar.bz2  
'''4. Compile and install '''
 cd libnfc-1.7.1
 ./configure --prefix=/usr --sysconfdir=/etc
 make
 sudo make install 
'''5. Write the configuration file for NFC communication'''

 cd /etc
 sudo mkdir nfc
 sudo nano /etc/nfc/libnfc.conf
Check the following details of the file ''etc/nfc/libnfc.conf'': 
<pre>
# Allow device auto-detection (default: true)
# Note: if this auto-detection is disabled, user has to set manually a device
# configuration using file or environment variable
allow_autoscan = true

# Allow intrusive auto-detection (default: false)
# Warning: intrusive auto-detection can seriously disturb other devices
# This option is not recommended, user should prefer to add manually his device.
allow_intrusive_scan = false

# Set log level (default: error)
# Valid log levels are (in order of verbosity): 0 (none), 1 (error), 2 (info), 3 (debug)
# Note: if you compiled with --enable-debug option, the default log level is "debug"
log_level = 1

# Manually set default device (no default)
# To set a default device, you must set both name and connstring for your device
# Note: if autoscan is enabled, default device will be the first device available in device list.
#device.name = "_PN532_SPI"
#device.connstring = "pn532_spi:/dev/spidev0.0:500000"
device.name = "_PN532_I2c"
device.connstring = "pn532_i2c:/dev/i2c-1"
</pre>

'''6. Wiring'''<br>
Toggle the switch to the '''I2C mode'''''

{|class="wikitable"
|-
|SEL0
|SEL1
|-
|H
|L
|-
|}
Pin diagram of Raspberry pi<br>
[[File:Raspberry.jpg]]
<br>
Connect the devices: 
{|class="wikitable"
|-
|PN532
|Raspberry
|-
|5V
|5V
|-
|GND
|GND
|-
|SDA
|SDA0
|-
|SCL
|SCL0
|}

'''7. Run ''i2cdetect –y 1'' to check whether the I2C device is recognized.'''<br>
If yes, it means both the module and the wiring work well.<br>
Then type in ''nfc-list'' to check the NFC module: <br>
[[File:I2C-1.png]]<br>
Run ''nfc-poll'' to scan the RFID tag and you can read information on the card: <br>
[[File:I2C-2.png]]<br>

=='''SPI Communication Instructions for Raspberry Pi'''==
'''1. Open SPI of the Raspberry Pi:''' 
 sudo raspi-config
Select '''9 Advanced Options''' -> '''SPI''' -> '''yes'''.<br>
'''2. Install some dependent packages'''
 sudo apt-get update
 sudo apt-get install libusb-dev libpcsclite-dev i2c-tools
'''3. Download and unzip the source code package of libnfc'''
 cd ~
 wget http://dl.bintray.com/nfc-tools/sources/libnfc-1.7.1.tar.bz2
 tar -xf libnfc-1.7.1.tar.bz2  
'''4. Compile and install '''
 cd libnfc-1.7.1
 ./configure --prefix=/usr --sysconfdir=/etc
 make
 sudo make install 
'''5. Write the configuration file for NFC communication'''
 cd /etc
 sudo mkdir nfc
 sudo nano /etc/nfc/libnfc.conf
Check the following details of the file ''etc/nfc/libnfc.conf'': 
<pre>
# Allow device auto-detection (default: true)
# Note: if this auto-detection is disabled, user has to set manually a device
# configuration using file or environment variable
allow_autoscan = true

# Allow intrusive auto-detection (default: false)
# Warning: intrusive auto-detection can seriously disturb other devices
# This option is not recommended, user should prefer to add manually his device.
allow_intrusive_scan = false

# Set log level (default: error)
# Valid log levels are (in order of verbosity): 0 (none), 1 (error), 2 (info), 3 (debug)
# Note: if you compiled with --enable-debug option, the default log level is "debug"
log_level = 1

# Manually set default device (no default)
# To set a default device, you must set both name and connstring for your device
# Note: if autoscan is enabled, default device will be the first device available in device list.
device.name = "_PN532_SPI"
device.connstring = "pn532_spi:/dev/spidev0.0:500000"
#device.name = "_PN532_I2c"
#device.connstring = "pn532_i2c:/dev/i2c-1"
</pre>
'''6. Wiring'''<br>
Toggle the switch to the '''SPI mode'''
{|class="wikitable"
|-
|SEL0
|SEL1
|-
|L
|H
|-
|}
Connect the devices: 
{|class="wikitable"
|-
|PN532
|Raspberry
|-
|5V
|5V
|-
|GND
|GND
|-
|SCK
|SCKL
|-
|MISO
|MISO
|-
|MOSI
|MOSI
|-
|NSS
|CE0
|}
'''7. Run ''ls /dev/spidev0.*'' to check whether the SPI is opened or not.'''<br>
If yes, it means both the module and the wiring work well.<br>
Then type in ''nfc-list'' to check the NFC module: <br>
''/dev/spidev0.0  /dev/spidev0.1''<br>
If two devices are detected, it means the SPI is already opened.<br>
Then type in ''nfc-list'' to check the NFC module: <br>
[[File:SPI-1.png]]<br>
For Raspberry Pi 3,you may be appear the following error:
You should 
 sudo nano /etc/nfc/libnfc.conf

After test, we know that currently for using the Raspberry Pi 3 model B in the SPI way, there will be an error prompt of TFI Mismatch, while this does not happen to the model B+ and 2 model B. '''<br>
[[File:SPI-3.png]]<br>

Run ''nfc-poll'' to scan the RFID tag and you can read information on the card:<br>
[[File:SPI-2.png]]<br>