getshot.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# getshot.py - gets a single screenshot from an UT2025B scope
#
# Copyright (c) 2011 András Veres-Szentkirályi
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.

import usb.core, sys

class Endpoint(object):
    BULK_IN = 0x82

class ReqType(object):
    VENDOR_REQUEST = 0x40
    RECIPIENT_ENDPOINT = 0x02
    DEVICE_TO_HOST = 0x80
    HOST_TO_DEVICE = 0x00

    CTRL_OUT = RECIPIENT_ENDPOINT | VENDOR_REQUEST | HOST_TO_DEVICE
    CTRL_IN  = RECIPIENT_ENDPOINT | VENDOR_REQUEST | DEVICE_TO_HOST

dev = usb.core.find(idVendor=0x5656, idProduct=0x0832)
if dev is None:
    print >>sys.stderr, 'USB device cannot be found, check connection'
    sys.exit(1)

dev.set_configuration()
dev.ctrl_transfer(ReqType.CTRL_OUT, 177, 0x2C, 0)
dev.ctrl_transfer(ReqType.CTRL_IN, 178, 0, 0, 8)
for i in [0xF0] + [0x2C] * 10 + [0xCC] * 10 + [0xE2]:
    dev.ctrl_transfer(ReqType.CTRL_OUT, 177, i, 0)

try:
    dev.ctrl_transfer(ReqType.CTRL_OUT, 176, 0, 38)
    for bufsize in [8192] * 4 + [6144]:
        buf = dev.read(Endpoint.BULK_IN, bufsize, 0)
        buf.tofile(sys.stdout)
    dev.ctrl_transfer(ReqType.CTRL_OUT, 177, 0xF1, 0)
except usb.core.USBError:
    print >>sys.stderr, 'Image transfer error, try again'
    sys.exit(1)