rfid pn532 invalid gpio with up2squared board

[Orch3strator]

Hello,

I've got a rfid board PN532 connected to the I2C bus via the groove board and directly to the GPIO ping 3 and 5. Here's what I was able to get to so far:
Connected directly to I2C:
nfc-scan-device -v
nfc-scan-device uses libnfc 1.7.1
1 NFC device(s) found:

• pn532_i2c:/dev/i2c-5:
  pn532_i2c:/dev/i2c-5
  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)

nfc-list
nfc-list uses libnfc 1.7.1
NFC device: pn532_i2c:/dev/i2c-5 opened
1 ISO14443A passive target(s) found:
ISO/IEC 14443A (106 kbps) target:
ATQA (SENS_RES): 00 04
UID (NFCID1): cb c2 94 0b
SAK (SEL_RES): 08

If' I connect the pn532 via the groove shield I get nothing. If I scan the I2C bus first, I get nothing (have to reboot the machine to get the nfc commands working again.)

Using the python example with mraa/upm I get this error message:
Example from: https://github.com/intel-iot-devkit/upm/blob/master/examples/python/pn532.py

python rfid.py
Traceback (most recent call last):
File "rfid.py", line 68, in
main()
File "rfid.py", line 11, in main
myNFC = upmPn532.PN532(3, 2)
File "/usr/lib/python2.7/dist-packages/upm/pyupm_pn532.py", line 246, in init
this = _pyupm_pn532.new_PN532(*args)
ValueError: UPM Invalid Argument: Invalid GPIO pin specified

python3 rfid.py
Traceback (most recent call last):
File "rfid.py", line 68, in
main()
File "rfid.py", line 11, in main
myNFC = upmPn532.PN532(3, 2)
File "/usr/lib/python3.5/dist-packages/upm/pyupm_pn532.py", line 246, in init
this = _pyupm_pn532.new_PN532(*args)
ValueError: UPM Invalid Argument: Invalid GPIO pin specified

I've changed to pin 3 and 5 according to https://wiki.up-community.org/Pinout_UP2 to no avail.

Any suggestions on how to get this to work with mraa/upm and python?
mraa version installed: 2.0.0.-2
upm version installed: 1.7.1-1

Regards, O.

[Propanu]

Hi @Orch3strator, unfortunately the UPM Python documentation doesn't include descriptions for the constructor unless you expand the source and that's easy to overlook. However, if you scroll to the init function here you will notice that 4 arguments are used to successfully initialize the PN532 modules: IRQ pin, RST pin, I2C bus, I2C address. Implicit values are used for the I2C bus, but in your case I think you'll have to use the full constructor. The 2 pin values you changed in the example are not the I2C bus, rather separate GPIOs required to use the module.

[Orch3strator]

Thank you @Propanu. I'm using the GrovePi board and added to my python script:

def initGrove():
	    #The UP^2 treats the shield as a sub platform over I2C 
	    mraa.addSubplatform(mraa.GROVEPI, "0")

initGrove()  

However, I can't figure out what to use for: IRQ pin, RST pin, I2C bus, I2C address.
My libnfc.conf points to:
device.name = "PN532 over I2C"
device.connstring = "pn532_i2c:/dev/i2c-5"

Appreciate your help. Regards, O.

[Orch3strator]

@Propanu Do I need to wire IRQ & RST pin to GPIO pin 2 & 3 while using I2C bus? As documented at UPM PN532

There are only 4 wires connected with other platforms. See Grove NFC