# RFID reader (PN532)

<abstract>
This article illustrates how to connect a PN532 RFID reader to a CM-Panel basic and how
to manage it
</abstract>

<img width="360px" src="PN532-NFC-RFID.jpg">

We will use the SPI bus to talk with the PN532 board. Wire this lines:

| PN532 | EXP-1             |
|-------|-------------------|
| VCC   | 3V3               |
| GND   | GND               |
| SCK   | 39 SPI0_SCLK      |
| MSO   | 37 SPI0_MISO      |
| MOSI  | 38 SPI0_MOSI      |
| SS    | 36 SPI0_CE0       |


and insert these lines in /boot/config.txt to enable the SPI interface and move it on
the pin 35-39 used by teh CM3-Panel:

	dtparam=spi=on
	dtoverlay=spi-gpio35-39

Set the dipswitch on the PN532 board to enable the SPI bus instead of I2C 

Install Node-RED:

* <https://nodered.org/docs/getting-started/raspberrypi>

Install this node inside Node-RED :

* [node-red-contrib-pn532](https://flows.nodered.org/node/node-red-contrib-pn532)

And this software from the command line:


	sudo apt update
	sudo apt install python-pip	
	sudo pip install RPi.GPIO
	sudo pip install spidev

## Links 

* [PN532 NFC RFID Module User Guide](http://www.elechouse.com/elechouse/images/product/PN532_module_V3/PN532_%20Manual_V3.pdf)
* <https://github.com/atsage/node-red-contrib-PN532>
* <https://osoyoo.com/2017/07/20/pn532-nfc-rfid-module-for-raspberry-pi/>
* <https://www.raspberrypi.org/documentation/hardware/raspberrypi/spi/README.md>

## Read a NFC card in Python

Install the NFC tools:

	sudo apt update
	sudo apt install libnfc5 libnfc-bin libnfc-examples
	
Configure the NFC tool editing this file:

	sudo nano /etc/nfc/libnfc.conf
	
and adding on it these two lines:

	device.name = "_PN532_SPI"
	device.connstring = "pn532_spi:/dev/spidev0.0:280000"

List connected NFC readers:

	nfc-scan-device -v

	nfc-scan-device uses libnfc 1.7.1
	1 NFC device(s) found:
	- pn532_i2c:/dev/i2c-1:
	    pn532_i2c:/dev/i2c-1
	chip: PN532 v1.6
	initator mode modulations: ISO/IEC 14443A (106 kbps), FeliCa (424 kbps, 212 kbps), ISO/IEC 14443-4B (106 kbps), Innovision Jewel (106 kbps), D.E.P. (424 kbps, 212 kbps, 106 kbps)
	target mode modulations: ISO/IEC 14443A (106 kbps), FeliCa (424 kbps, 212 kbps), D.E.P. (424 kbps, 212 kbps, 106 kbps)
	
Read a card or tag by first starting nfc-poll then physically holding a NFC/RFID tag or card 
in front of the reader:

	nfc-poll 
	
	nfc-poll uses libnfc 1.7.1
	NFC reader: pn532_i2c:/dev/i2c-1 opened
	NFC device will poll during 30000 ms (20 pollings of 300 ms for 5 modulations)
	ISO/IEC 14443A (106 kbps) target:
	    ATQA (SENS_RES): 00  04  
	       UID (NFCID1): 77  d3  d1  ad  
	      SAK (SEL_RES): 08  
	nfc_initiator_target_is_present: Target Released
	Waiting for card removing...done.

Install git on your CM3-Panel:

	sudo apt install git
	
Then clode this Python library:

	git clone https://github.com/HubCityLabs/py532lib.git
	
move inside the directory:

	cd py532lib
	
and edit this Python3 program in a file called <b>readcard.py</b>:

	from py532lib.i2c import *
	from time import sleep
	
	pn532=Pn532_i2c()
	pn532.SAMconfigure()
	
	while True:
	        data=pn532.read_mifare().get_data()
	        if  len(data)==11:
	                uid="%02X%02X%02X%02X" % (data[7],data[8],data[9],data[10])
	                print(uid)
	                sleep(1)
	        else:
	                sleep(1)

run it by typing:

	python3 readcard.py
	
## Links 

* [Setting up a PN532 NFC module on a Raspberry Pi using I2C](https://blog.stigok.com/2017/10/12/setting-up-a-pn532-nfc-module-on-a-raspberry-pi-using-i2c.html)
* [Python3 py532lib](https://github.com/HubCityLabs/py532lib)


@include='adv_cmpanel'