我用串行编写了一个简单的串口控制器 - 实际上，它是更多的Frankstein代码，其他人编写的碎片和我拼凑在一起。随意嘲笑我的无能，但任何方向都会受到赞赏。它在运行Backtrack，Python 2.6的Linux上运行良好，但是当我尝试在Raspberry Pi，Python 2.7上运行它时，我得到了这些错误：
Traceback (most recent call last):Exception in thread Thread-2:
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 551, in __bootstrap_inner
self.run()
File "/usr/lib/python2.7/threading.py", line 504, in run
self.__target(*self.__args, **self.__kwargs)
File "/home/pi/Zombie Python 1.2 (Modified for Pi) (from Adapt 1.7).py", line 147, in rx
self.ser = serial.Serial('/dev/ttyUSB0', 9600, timeout=1, bytesize=8, stopbits=1)
File "/usr/local/lib/python2.7/dist-packages/serial/serialutil.py", line 260, in __init__
self.open()
File "/usr/local/lib/python2.7/dist-packages/serial/serialposix.py", line 276, in open
raise SerialException("could not open port %s: %s" % (self._port, msg))
SerialException: could not open port /dev/ttyUSB0: [Errno 2] No such file or directory: '/dev/ttyUSB0'
File "/home/pi/Zombie Python 1.2 (Modified for Pi) (from Adapt 1.7).py", line 185, in <module>
client = ThreadedClient(root)
File "/home/pi/Zombie Python 1.2 (Modified for Pi) (from Adapt 1.7).py", line 113, in __init__
self.periodicCall()
File "/home/pi/Zombie Python 1.2 (Modified for Pi) (from Adapt 1.7).py", line 119, in periodicCall
self.gui.processIncoming()
AttributeError: GuiPart instance has no attribute 'processIncoming'
我的代码是：
import Tkinter
import time
import threading
import random
import Queue
import serial
import readline
#import xbee
import sys
x=""
class GuiPart:
def __init__(self, master, queue, endApplication):
self.sonar = Tkinter.StringVar() # Feeds sonar sensor data to label
self.lm = Tkinter.StringVar() # Feeds left motor speed to label
self.rm = Tkinter.StringVar() # Feeds right motor speed to label
self.queue = queue
# Set up the GUI
frame1 = Tkinter.Frame(master, bd=200) #Setup frame.
frame1.bind("<Key>", key) # Allow frame to handle keypresses.
frame1.focus_set() #Set focus of frame so that keypresses activate event.
frame1.pack() #Show it.
#Button
console = Tkinter.Button(frame1, text='Close', command=endApplication)
console.pack()
# Add more GUI stuff here
self.lm.set(0) # Initializes left motor label
self.rm.set(0) # Initializes right motor label
self.sonar.set(0) # Initializes sonar label
#Sonar label
sonarLbl = Tkinter.Label(frame1, textvariable=self.sonar)
sonarLbl.pack()
#Right motor label
rmLbl = Tkinter.Label(frame1, text="Left Motor Speed: ", textvariable=self.rm)
rmLbl.pack()
#Left motor label
lmLbl = Tkinter.Label(frame1, textvariable=self.lm)
lmLbl.pack()
def key(self, event):
#print "pressed", repr(event.char)
#self.sonar = repr(event.char) <------ This should be the line to handle keypresses
global x
x = repr(event.char)
def processIncoming(self):
"""
Handle all the messages currently in the queue (if any).
"""
while self.queue.qsize():
try:
msg = self.queue.get(0)
# Check contents of message and do what it says
# As a test, we simply print it
# Below is where I will parse the "msg" variable, splitting
# it (msg.rsplit) to pull out sensor data and update labels.
lm, rm, sonar, mknt = msg.rsplit(",")
lm = "Left Motor Speed: "+lm
rm = "Right Motor Speed: "+rm
sonar = "Sonar: "+sonar+" CMs away"
self.sonar.set(sonar) # Setting the labels with latest sensor info.
self.lm.set(lm) # Setting the labels with latest sensor info.
self.rm.set(rm) # Setting the labels with latest sensor info.
except Queue.Empty:
pass
class ThreadedClient:
"""
Launch the main part of the GUI and the worker thread. periodicCall and
endApplication could reside in the GUI part, but putting them here
means that you have all the thread controls in a single place.
"""
def __init__(self, master):
"""
Start the GUI and the asynchronous threads. We are in the main
(original) thread of the application, which will later be used by
the GUI. We spawn a new thread for the worker.
"""
self.master = master
# Create the queue
self.queue = Queue.Queue()
# Set up the GUI part
self.gui = GuiPart(master, self.queue, self.endApplication)
# Set up the thread to do asynchronous I/O
# More can be made if necessary
self.running = 1
self.thread1 = threading.Thread(target=self.workerThread1)
self.thread1.start()
#Start receiving thread.
self.rx = threading.Thread(target=self.rx)
self.rx.start()
# Start the periodic call in the GUI to check if the queue contains
# anything
self.periodicCall()
def periodicCall(self):
"""
Check every 100 ms if there is something new in the queue.
"""
self.gui.processIncoming()
if not self.running:
# This is the brutal stop of the system. You may want to do
# some cleanup before actually shutting it down.
import sys
sys.exit(1)
self.master.after(100, self.periodicCall)
def workerThread1(self):
"""
This is where we handle the asynchronous I/O. For example, it may be
a 'select()'.
One important thing to remember is that the thread has to yield
control.
"""
while self.running:
# To simulate asynchronous I/O, we create a random number at
# random intervals. Replace the following 2 lines with the real
# thing.
time.sleep(rand.random() * 0.3)
msg = rand.random()
#self.queue.put(msg)
# Continuously read and print packets
def rx(self):
global x
self.ser = serial.Serial('/dev/ttyUSB0', 9600, timeout=1, bytesize=8, stopbits=1)
self.ser.flush()
while(1):
response = str(self.ser.readline())
# Send movement codes.
if x == "'a'" or x == "'A'": # or "'A'": # Turn left.
self.ser.write('4')
elif x == "'w'" or x == "'W'": #Go forward.
self.ser.write("3")
elif x == "'d'" or x == "'D'": #Turn right.
self.ser.write("2")
elif x == "'s'" or x == "'S'": #Go back.
self.ser.write("1")
elif x == "'x'" or x == "'X'": #Stop.
self.ser.write("5")
elif x == "'1'": #Raise speed.
self.ser.write("7")
elif x == "'2'": #Lower speed.
self.ser.write("6")
x = ""
if len(response) > 10:
self.ser.flushInput() #If you don't flush the buffer, then it'll try to read out all
#the sensor readings, so the reaction time will be extrordinary.
time.sleep(.1)# This scales back the CPU usage.
self.queue.put(response)
def endApplication(self):
print "Closing"
self.running = 0
self.ser.close()
sys.exit(1)
rand = random.Random()
root = Tkinter.Tk()
client = ThreadedClient(root)
root.mainloop()
答案 0 :(得分：1)
您的self.gui是GuiPart。 GuiPart没有processIncoming。
答案 1 :(得分：0)
在行
上方显示的代码段中def key(self, event):
和
def processIncoming(self):
不再缩进四个空格，因为它们可能应该成为您的班级GuiPart的方法。
来自其他语言的Python新手经常会错过缩进是Python编程语言中语法非常重要部分的细节。因此，避免混合TAB和空间也是非常必要的。 （特别是在从各种来源复制代码片段时，否则 学习和尝试新事物的好机会）
另一件事是：在Python中，您还可以定义模块级全局函数。 执行此操作的语法实际上与用于在类中定义方法的语法相同（除了缩进级别）。
因此，在您的示例代码段中，以前的方法key()和processIncoming()已成为模块全局函数定义，而不是仅通过错误缩进的方法。
方法是类对象的属性。这两种方法都被移动了 从类名空间一级到模块名称空间。 因此出现以下错误消息：
AttributeError: GuiPart instance has no attribute 'processIncoming'