我在Raspberry Pi 3上遇到了从USB读取序列的问题。 我正在阅读的设备是Arduino NANO。对于基于Windows的计算机，代码非常简洁。
然而，在Raspberry Pi 3（debian jessie）上，我发现在读取串口时我的CPU使用率是100％。这些是我安装的软件包：
python-pygame python-serial python-netifaces cu python-wxgtk3.0
我使用此代码检查串行输入而不停止：
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import config
from config import officialwebsite
import pygame
from pygame.locals import *
import serial
import sys
import glob
import time
#
####################
# New Fresh class that handle all input types at once
####################
class CInput():
def __init__(self,Logs,Config,myDisplay):
self.Logs=Logs
self.shift=False
self.clock = pygame.time.Clock()
self.Config = Config
self.Lang=None
self.ConfigKeys=Config.ConfigFile['SectionKeys']
self.last_click = 0
self.myDisplay=myDisplay
self.ser = False # Init serial connexion
####### SERIAL
def Serial_Connect(self):
self.SerialBypass = bool(self.Config.GetValue('SectionAdvanced','noserial'))
# Check input serial port (if no param --noserial)
if not self.SerialBypass:
try:
if self.Config.detectedserialport:
serialport=self.Config.detectedserialport
else:
serialport=self.Config.GetValue('SectionGlobals','serialport')
serialspeed = int(self.Config.GetValue('SectionGlobals','serialspeed'))
self.ser = serial.Serial(serialport,serialspeed)
self.Logs.Log("DEBUG","Successfully loaded serial port {} at speed {}".format(serialport,serialspeed))
except:
self.Logs.Log("FATAL","Unable to load serial port : {} . Common errors are : \n * Your board is not connected \n * Your config file is not set properly (pydarts.cfg in your home folder)\n * Your arduino driver is not installed properly (windows only)\n * You're not part of the dialout group (Linux only).\n -- Note : You can use --noserial argument to bypass serial connection.".format(self.Config.GetValue('SectionGlobals','serialport')))
self.myDisplay.PlaySound('whatamess')
self.myDisplay.InfoMessage([self.Lang.lang['serial-issue-1'],self.Lang.lang['serial-issue-2'],self.Lang.lang['serial-issue-3'],officialwebsite,self.Lang.lang['serial-issue-4']],None,None,'middle','small')
sys.exit(2)
else:
self.Logs.Log("DEBUG","Serial connection bypass as requested. No need for a dart board mate !")
#
# Flush
#
def Serial_Flush(self):
if not self.SerialBypass:
try:
self.ser.flushInput() #Flush Serial input values (prevent user to hit while prog sleeps)
except:
self.Logs.Log("DEBUG","Unable to flush input from serial port.")
else:
self.Logs.Log("DEBUG","Bypassing serial port flush")
#
# Read serial connection.
#
def Serial_Read(self,context=False):
DartStroke = False
KeyStroke = False
# Listen on serial cx
try:
# This event (get) solve the bug on windows (waiting screen)
pygame.event.get()
# Read into the serial buffer if there is somthing inside
serdata=False
try:
serdata=self.ser.in_waiting()#pyserial v2.x
except:
pass
try:
serdata=self.ser.inWaiting()#pyserial v3.x
except:
pass
if serdata: #Read only if there is something in the serial buffer (non-blocking mode)
DartStroke=self.ser.read()
DartStroke=DartStroke.decode(encoding='UTF-8')
except Exception as e:
print("Error {}".format(e))
#print(DartStroke)
# Find unique key in config dict. Returns uppercase (only if something has been hit on board)
if DartStroke:
for TheKey, TheConfig in self.ConfigKeys.items():
if TheConfig == DartStroke:
KeyStroke=TheKey.upper()
# Debug Serial Input (only if something has been hit on board)
if DartStroke and KeyStroke:
self.Logs.Log("DEBUG","DEBUGINPUT : You hit \"{}\" which is associated to \"{}\" in your configuration file.".format(DartStroke,KeyStroke))
elif DartStroke and KeyStroke==False:
self.Logs.Log("DEBUG","You hit \"{}\" which doesn't exists in your configuration file.".format(DartStroke))
# If asked to return KEY, else return VAL
if context=='wizard':
return DartStroke
else:
return KeyStroke
#### KEYBOARD & MOUSE (from pygame)
# Context can be different, dependanding from where this method is used. So far : 'menus' or 'game'
#
def KbdAndMouse(self,ktype, specials, context=None):
keypressed = ""
realkey=-1
double_click_duration=500
clicktype=False
events = pygame.event.get()
for event in events:
if event.type == pygame.QUIT:
print("Exit requested")
sys.exit(0)
# Case of Key UP
if event.type == KEYUP:
if pygame.key.name(event.key) == 'left shift':
self.shift=False
# Case of key PRESSED
if event.type == KEYDOWN:
#self.clock.tick(30)
keyname = pygame.key.name(event.key)
unicodekey = event.dict['unicode']
if len(keyname)==1 and unicodekey!='':
keycouple = self.RealKey(unicodekey,context)
else:
keycouple = self.RealKey(keyname,context)
realkey = keycouple[1]# Get pydarts translation of key
realtype = keycouple[0]# Get pydarts translation of key type (alpha, fx, num, etc...)
#print("Key analysis : original {}, translated as {} in unicode and {} in pydarts key".format(keyname,unicodekey,realkey))
if realkey in specials:# return special key if allowed
return realkey
elif realtype in ktype:# Return standard key if allowed/expected
return realkey
# Case of MOUSE BUTTON PRESSED
if event.type == pygame.MOUSEBUTTONDOWN:
#on click
self.clock.tick(30)
self.diff = self.clock.get_time()
if self.diff <= double_click_duration:
clicktype='double-click'
#self.clock.tick()
#self.last_click = 0
else:
clicktype='single-click'
#self.last_click = self.now
if clicktype:
keycouple = self.RealKey(clicktype,context)
realkey = keycouple[1]# Get pydarts translation of key
realtype = keycouple[0]# Get pydarts translation of key type (alpha, fx, num, etc...)
if realkey in specials:
return realkey
# Everything else failed, return -1 (0 is a valid char)
return -1
def ListenInputs(self,ktype=['num','alpha','fx','arrows'], specials = ['enter','tab','backspace','left shift','escape','space','double-click','single-click'] ,WaitFor=[], context='menus'):
SerialInput = False
pyGameInput = -1
while True:
# First try to read serial
if not self.SerialBypass:
#print("Before serial")
SerialInput = self.Serial_Read(context)
#print("After serial")
# If serial returns false, try to read keyboard
if not SerialInput:
#print("Before pyGame Input")
pyGameInput = self.KbdAndMouse(ktype,specials,context)
#print("After pyGame Input")
# If any input return anything, exit from loop
if pyGameInput!=-1:
self.Logs.Log("DEBUG","Input debug : {}".format(pyGameInput))
# Return Serial input if expected (or if nothing expected)
if (SerialInput and WaitFor==[]) or (SerialInput in WaitFor):
return SerialInput
# Return pyGame input if expected (or if nothing expected)
if (pyGameInput!=-1 and WaitFor==[]) or (pyGameInput in WaitFor):
return pyGameInput
#### COMMON
#
# Function to get key and type from current state
#
def RealKey(self,keypressed,context):
if (keypressed == "&" and self.shift) or keypressed=="[1]" or keypressed=="1":
kvalue = 1
ktype = 'num'
elif (keypressed == "world 73" and self.shift) or keypressed=="[2]" or keypressed=="2":
kvalue = 2
ktype = 'num'
elif (keypressed == "\"" and self.shift) or keypressed=="[3]" or keypressed=="3":
kvalue = 3
ktype = 'num'
elif (keypressed == "'" and self.shift) or keypressed=="[4]" or keypressed=="4":
kvalue = 4
ktype = 'num'
elif (keypressed == "(" and self.shift) or keypressed=="[5]" or keypressed=="5":
kvalue = 5
ktype = 'num'
elif (keypressed == "-" and self.shift) or keypressed=="[6]" or keypressed=="6":
kvalue = 6
ktype = 'num'
elif (keypressed == "world 72" and self.shift) or keypressed=="[7]" or keypressed=="7":
kvalue = 7
ktype = 'num'
elif (keypressed == "_" and self.shift) or keypressed=="[8]" or keypressed=="8":
kvalue = 8
ktype = 'num'
elif (keypressed == "world 71" and self.shift) or keypressed=="[9]" or keypressed=="9":
kvalue = 9
ktype = 'num'
elif (keypressed == "world 64" and self.shift) or keypressed=="[0]" or keypressed=="0":
kvalue = 0
ktype = 'num'
elif (keypressed == "=" and self.shift) or keypressed=="[+]":
kvalue = '+'
ktype = 'math'
elif (keypressed == "*" and self.shift==False) or keypressed=="[*]":
kvalue = '*'
ktype = 'math'
elif (keypressed == "-" and self.shift==False) or keypressed=="[-]":
kvalue = '-'
ktype = 'math'
elif (keypressed == ":" and self.shift) or keypressed=="[/]":
kvalue = '/'
ktype = 'math'
elif (keypressed == "world 64" and self.shift) or keypressed=="[0]" or keypressed=="0":
kvalue = 0
ktype = 'math'
elif (keypressed == ";" and self.shift) or keypressed==".":
kvalue = '.'
ktype = 'alpha'
elif keypressed == "down" or keypressed == "up" or keypressed == "right" or keypressed == "left":
kvalue = keypressed
ktype = 'arrows'
elif keypressed == 'escape' and context=='game': # In-game context, escape means ABORT
kvalue='GAMEBUTTON'
ktype='special'
elif keypressed == 'escape': # All others context, it means 'escape'
kvalue=keypressed
ktype = 'special'
elif keypressed == 'space' and context=='game': # In-game context, space means NEXT PLAYER
kvalue='PLAYERBUTTON'
ktype='special'
elif keypressed == 'space': # All other context, space means 'space'
kvalue=keypressed
ktype='special'
elif keypressed == 'enter' or keypressed=='return': # Enter and Return are comfunded volontarily
kvalue='enter'
ktype='special'
elif keypressed == 'tab':
kvalue=keypressed
ktype='special'
elif keypressed == 'backspace':
kvalue=keypressed
ktype='special'
elif keypressed == 'b' and context=='game': # In-game, 'b' means 'BACKUPTURN'
kvalue='BACKUPBUTTON'
ktype='special'
elif (keypressed == 'f' or keypressed=='double-click'): # Everywhere, 'f' and double-click means "Fullscreen"
kvalue='TOGGLEFULLSCREEN'
ktype='special'
elif keypressed == 'left shift':
kvalue=keypressed
ktype='special'
self.shift=True #Enable Shift !
# Other special chars, need to be at the end (based on length)
elif (len(keypressed)== 2 or len(keypressed)==3) and keypressed[:1] == "f": # Detect Fx keys
kvalue = keypressed
ktype = 'fx'
elif len(keypressed)== 1:# Detect any other key (simple alpha keys)
kvalue = keypressed
ktype = 'alpha'
else:
kvalue=None
ktype=None
return [ktype,kvalue]
我不确定如何解决100％CPU问题。某处有time.sleep(0.3)陈述会有帮助吗？在debian jessie上，有没有人对Raspberry Pi 3中的串行CPU负载有更多的经验？
答案 0 :(得分：0)
while True:
pygame.time.wait(5)# A few ms to reduce cpu...
in True而解决问题！