用MSN控制伺服电机
测试通过MSN控制ServoMotor基本成功，注意一定要root用户，另外MSNP的charset为utf－8
条件：Phidgets硬件（伺服接口板，伺服电机，也可以使用Arduino实现）
伺服电机控制端，可以是PC或单板机（具有USB HOST）
MSNP（MSN的python实现）
Phidgets驱动和PythonPhidgets（Phidgets的python实现）
PhidgetsMsnContoller.py(自己的程序）
示意图如下：
基本代码如下：
#Simple control protocol:
#Command: ctype, para1, para2
# get board attach status: ctype ex: 0 (get servo board attach status)
# get motor engage status: ctype, index ex: 1, 0 (get servo motor index 0 engage status)
# get position status: ctype, index ex: 2, 0 (get servo motor index 0 postion status)
# set position status: ctype, index, pos ex: 3, 0, 100 (servo motor index 0 move to position 100)
#Status: stype, para1, para2
# board attach/detach status: stype, val ex: 0, 0, 0/1 (servo board detached/attached)
# motor engage/disengage status: stype, index, val ex: 1, 0, 0/1 (servo motor index 0 disengage/engage)
# position status: stype, index, pos ex: 2, 0, 100 (servo motor index 0 moved to position 100)
#Basic imports
from ctypes import *
import sys
from time import sleep
#Phidget specific imports
from Phidgets.PhidgetException import *
from Phidgets.Events.Events import *
from Phidgets.Devices.Servo import Servo
#Msn imports
import msnp
class MsnChatListener(msnp.ChatCallbacks):
def message_received(self, passport_id, display_name, text, charset):
print '%s: %s' % (passport_id, text)
self.chat.send_message(text, charset)
self.sb.ProcessCmd(text)
class MsnListener(msnp.SessionCallbacks):
def __init__(self):
self.sb = ServoBoard(self)
def chat_started(self, chat):
callbacks = MsnChatListener()
chat.callbacks = callbacks
callbacks.chat = chat
callbacks.sb = self.sb
self.sb.chat = chat
self.sb.onChat = True
def state_changed(self, state):
if state == msnp.States.ONLINE:
print 'You are now online.'
self.online = True
self.sb.open()
self.sb.attach()
elif state == msnp.States.OFFLINE:
print 'You are now offline.'
self.online = False
self.sb.close()
class MsnController():
def beginMsnControl(self):
self.msnListener = MsnListener()
msn = msnp.Session(self.msnListener)
msn.login('[email protected]', 'xxx')
msn.sync_friend_list()
while True:
msn.process(chats = True)
sleep(1)
########################################################
class ServoBoard:
def __init__(self, listener):
#Create an servo object
self.servo = Servo()
self.listener = listener
self.charset = 'utf-8'
self.onChat = False
def ReportStatus(self, type, para1, para2):
try:
text = str(type) + "," + str(para1) + "," + str(para2)
if(self.onChat):
self.chat.send_message(text, self.charset)
except:
print "Report status failed."
def ProcessCmd(self, text):
try:
cmd = text.split(',')
if cmd[0] == '0':
if(self.servo.isAttached()):
self.ReportStatus(0, 0, 1)
else:
self.ReportStatus(0, 0, 0)
elif cmd[0] == '1':
if(self.servo.getEngaged(int(cmd[1]))):
self.ReportStatus(1, int(cmd[1]), 1)
else:
self.ReportStatus(1, int(cmd[1]), 0)
elif cmd[0] == '2':
self.ReportStatus(2, int(cmd[1]), self.servo.getPosition(int(cmd[1])))
elif cmd[0] == '3':
self.servo.setPosition(int(cmd[1]), int(cmd[2]))
else:
pass
except:
print "Process command failed."
#Information Display Function
def DisplayDeviceInfo(self):
print "|------------|----------------------------------|--------------|------------|"
print "|- Attached -|- Type -|- Serial No. -|- Version -|"
print "|------------|----------------------------------|--------------|------------|"
print "|- %8s -|- %30s -|- %10d -|- %8d -|" % (self.servo.isAttached(), self.servo.getDeviceType(), self.servo.getSerialNum(), self.servo.getDeviceVersion())
print "|------------|----------------------------------|--------------|------------|"
print "Number of motors: %i" % (self.servo.getMotorCount())
#Event Handler Callback Functions
def ServoAttached(self, e):
attached = e.device
print "Servo %i Attached!" % (attached.getSerialNum())
self.ReportStatus(0, 0, 1)
def ServoDetached(self, e):
detached = e.device
print "Servo %i Detached!" % (detached.getSerialNum())
self.ReportStatus(0, 0, 0)
def ServoError(self, e):
print "Phidget Error %i: %s" % (e.eCode, e.description)
def ServoPositionChanged(self, e):
print "Motor %i Current Position: %f" % (e.index, e.position)
self.ReportStatus(2, e.index, e.position)
def open(self):
#Main Program Code
try:
self.servo.setOnAttachHandler(self.ServoAttached)
self.servo.setOnDetachHandler(self.ServoDetached)
self.servo.setOnErrorhandler(self.ServoError)
self.servo.setOnPositionChangeHandler(self.ServoPositionChanged)
except PhidgetException, e:
print "Phidget Exception %i: %s" % (e.code, e.message)
print "Exiting...."
exit(1)
print "Opening phidget object...."
try:
self.servo.openPhidget()
except PhidgetException, e:
print "Phidget Exception %i: %s" % (e.code, e.message)
print "Exiting...."
exit(1)
def attach(self):
print "Waiting for attach...."
try:
self.servo.waitForAttach(10000)
except PhidgetException, e:
print "Phidget Exception %i: %s" % (e.code, e.message)
try:
self.servo.closePhidget()
except PhidgetException, e:
print "Phidget Exception %i: %s" % (e.code, e.message)
print "Exiting...."
exit(1)
print "Exiting...."
exit(1)
else:
self.DisplayDeviceInfo()
def close(self):
print "Closing..."
try:
self.servo.closePhidget()
except PhidgetException, e:
print "Phidget Exception %i: %s" % (e.code, e.message)
print "Exiting...."
exit(1)
print "Done."
exit(0)
########################################################
if __name__ == "__main__":
mc = MsnController()
mc.beginMsnControl()
待解决问题：
不能取得电机是否连接的状态（getEngaged错误, - 是否因为驱动版本或硬件过时引起？changed getMotorStatus and setMotorStatus to getEngaged and setEngaged to reflect changes in the C API
）
在出错时向PC报告