Hi all, I want to access the NFC card reader(ACR 122) through python. Here is what i have done.
1st, run the lsusb to make sure the card reader is active on the usb port:
root@clanton:/media/mmcblk0p1/nfcpy/examples# lsusb | |
| Bus 001 Device 002: ID 072f:2200 | |
| Bus 001 Device 001: ID 1d6b:0001 | |
| Bus 002 Device 001: ID 1d6b:0002 |
2nd, install the python usb code from the sourceforge.
3rd, run the python script and get the error:
| root@clanton:/media/mmcblk0p1/nfcpy/examples# python tagtool.py | ||
| [nfc.clf] searching for reader with path 'usb' | ||
| Traceback (most recent call last): | ||
| File "tagtool.py", line 479, in <module> | ||
| TagTool().run() | ||
| File "/media/mmcblk0p1/nfcpy/examples/cli.py", line 283, in run | ||
| while self.run_once() and self.options.loop: | ||
| File "/media/mmcblk0p1/nfcpy/examples/cli.py", line 230, in run_once | ||
| try: clf = nfc.ContactlessFrontend(device) | ||
| File "/media/mmcblk0p1/nfcpy/nfc/clf.py", line 105, in __init__ | ||
| if path and not self.open(path): | ||
| File "/media/mmcblk0p1/nfcpy/nfc/clf.py", line 156, in open | ||
| self.dev = nfc.dev.connect(path) | ||
| File "/media/mmcblk0p1/nfcpy/nfc/dev/__init__.py", line 55, in connect | ||
| found = transport.USB.find(path) | ||
| File "/media/mmcblk0p1/nfcpy/nfc/dev/transport.py", line 169, in find | ||
| for d in cls.usb_core.find(find_all=True, **match)] | ||
| File "/usr/lib/python2.7/site-packages/usb/core.py", line 829, in find | ||
| raise ValueError('No backend available') | ||
| ValueError: No backend available |
It seems like the python script can not find the usb backend.
But here is the installed libusb package in the sysem:
root@clanton:/media/mmcblk0p1/nfcpy/examples# opkg list-installed | grep -i libusb
libusb-0.1-4 - 1:0.1.4-r1
libusb-1.0-0 - 1.0.9-r1
root@clanton:/media/mmcblk0p1/nfcpy/examples#
Is there anything i missed? Thanks for your help.