usb_receipt_printer_demo.py

import usb.core
import usb.util

"""Demo program to print to the POS58 USB thermal receipt printer. This is
labeled under different companies, but is made by Zijiang. See 
http:zijiang.com"""

# In Linux, you must:
#
# 1) Add your user to the Linux group "lp" (line printer), otherwise you will
#    get a user permissions error when trying to print.
#
# 2) Add a udev rule to allow all users to use this USB device, otherwise you
#    will get a permissions error also. Example:
#
#    In /etc/udev/rules.d create a file ending in .rules, such as
#    33-receipt-printer.rules with the contents:
#
#   # Set permissions to let anyone use the thermal receipt printer
#   SUBSYSTEM=="usb", ATTR{idVendor}=="0416", ATTR{idProduct}=="5011", MODE="666"

# Find our device
# 0416:5011 is POS58 USB thermal receipt printer
dev = usb.core.find(idVendor=0x0416, idProduct=0x5011)

# Was it found?
if dev is None:
    raise ValueError('Device not found')

# Disconnect it from kernel
needs_reattach = False
if dev.is_kernel_driver_active(0):
    needs_reattach = True
    dev.detach_kernel_driver(0)

# Set the active configuration. With no arguments, the first
# configuration will be the active one
dev.set_configuration()

# get an endpoint instance
cfg = dev.get_active_configuration()
intf = cfg[(0,0)]

ep = usb.util.find_descriptor(
    intf,
    # match the first OUT endpoint
    custom_match = \
    lambda e: \
        usb.util.endpoint_direction(e.bEndpointAddress) == \
        usb.util.ENDPOINT_OUT)

assert ep is not None

# write the data
ep.write('Hello, world!\n\n')
#         000000000111111111122222222223
#         123456789012345678901234567890
ep.write('Soluta sed voluptatem ut\n')
ep.write('facere aut. Modi placeat et\n')
ep.write('eius voluptate sint ut.\n')
ep.write('Facilis minima ex quia quia\n')
ep.write('consectetur ex ipsa. Neque et\n')
ep.write('voluptatem ipsa enim error\n')
ep.write('reprehenderit ex dolore.\n')
ep.write('Cupiditate ad voluptatem nisi.\n\n\n\n')

# Reattach if it was attached originally
dev.reset()
if needs_reattach:
    dev.attach_kernel_driver(0)
    print "Reattached USB device to kernel driver"