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#Copyright (c) 2011, 2012, Ian Daniher
#Copyright (c) 2012, Tony Forster, Walter Bender
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
import sys
import os
sys.path.append(os.path.dirname(__file__))
import usb.core
import logging
logger = logging.getLogger('WeDoMore')
UNAVAILABLE = None
TILTSENSOR = [38, 39]
DISTANCESENSOR = [176, 177, 178, 179]
MOTOR = [0, 1, 2, 3, 238, 239]
TILT_FORWARD = 0
TILT_LEFT = 1
TILT_RIGHT = 2
TILT_BACK = 3
NO_TILT = -1
def scan_for_devices():
''' Find all available devices '''
return usb.core.find(find_all=True, idVendor=0x0694, idProduct=0x0003)
class WeDo:
def __init__(self, device=None):
"""Find a USB device with the VID and PID of the Lego
WeDo. If the HID kernel driver is active, detatch
it."""
self.dev = None
self.number = 0
self.dev = device
if self.dev is None:
logging.debug("No Lego WeDo found")
else:
status = self.init_device()
if status is UNAVAILABLE:
logging.debug("WARNING: Could not talk to WeDo device.")
self.valMotorA = 0
self.valMotorB = 0
def init_device(self):
''' Reinit device associated with the WeDo instance '''
if self.dev is not None:
try:
if self.dev.is_kernel_driver_active(0):
try:
self.dev.detach_kernel_driver(0)
except: # usb.core.USBError as e:
e = ''
logger.error(
"Could not detatch kernel driver: %s" % (str(e)))
return UNAVAILABLE
except: # usb.core.USBError as e:
e = ''
logger.error("Could not talk to WeDo device: %s" % (str(e)))
return UNAVAILABLE
self.endpoint = self.dev[0][(0,0)][0]
return True
def getRawData(self):
"""Read 64 bytes from the WeDo's endpoint, but only
return the last eight."""
try:
data = list(self.endpoint.read(64)[-8:])
except: # usb.core.USBError as e:
e = ''
logger.error("Could not read from WeDo device: %s" % (str(e)))
return UNAVAILABLE
return data
def processMotorValues(self, value):
"""Check to make sure motor values are sane."""
retValue = int(value)
if 0 < value < 101:
retValue += 27
elif -101 < value < 0:
retValue -= 27
elif value == 0:
retValue = 0
return retValue
def setMotors(self, valMotorA, valMotorB):
"""Arguments should be in form of a number between 0
and 100, positive or negative. Magic numbers used for
the ctrl_transfer derived from sniffing USB coms."""
if self.dev is None:
return
self.valMotorA = self.processMotorValues(valMotorA)
self.valMotorB = self.processMotorValues(valMotorB)
data = [64, self.valMotorA&0xFF, self.valMotorB&0xFF,
0x00, 0x00, 0x00, 0x00, 0x00]
try:
self.dev.ctrl_transfer(bmRequestType = 0x21, bRequest = 0x09,
wValue = 0x0200, wIndex = 0,
data_or_wLength = data)
except: # usb.core.USBError as e:
e = ''
logger.error("Could not write to driver: %s" % (str(e)))
def getData(self):
"""Sensor data is contained in the 2nd and 4th byte, with
sensor IDs being contained in the 3rd and 5th byte
respectively."""
rawData = self.getRawData()
if rawData is not None:
sensorData = {rawData[3]: rawData[2], rawData[5]: rawData[4]}
else:
sensorData = {}
return sensorData
def processTilt(self, v):
"""Use a series of elif/value-checks to process the tilt
sensor data."""
if v in range(10, 40):
return TILT_BACK
elif v in range(60, 90):
return TILT_RIGHT
elif v in range(170, 190):
return TILT_FORWARD
elif v in range(220, 240):
return TILT_LEFT
elif v in range(120, 140):
return NO_TILT
else:
return NO_TILT
def getTilt(self):
if self.dev is None:
return UNAVAILABLE
data = self.getData()
for num in data.keys():
if num in TILTSENSOR:
return self.processTilt(data[num])
return UNAVAILABLE
def getDistance(self):
if self.dev is None:
return UNAVAILABLE
data = self.getData()
for num in data.keys():
if num in DISTANCESENSOR:
return data[num] - 69
return UNAVAILABLE
# TODO: check motor availability
def setMotorA(self, valMotorA):
self.setMotors(valMotorA, self.valMotorB)
return self.valMotorA
def setMotorB(self, valMotorB):
self.setMotors(self.valMotorA, valMotorB)
return self.valMotorB
def getMotorA(self):
if self.dev is None:
return UNAVAILABLE
if self.valMotorA == 0:
return 0
elif self.valMotorA < 0:
return self.valMotorA + 27
else:
return self.valMotorA - 27
def getMotorB(self):
if self.dev is None:
return UNAVAILABLE
if self.valMotorB == 0:
return 0
elif self.valMotorB < 0:
return self.valMotorB + 27
else:
return self.valMotorB - 27
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