Python SerialException:设备报告已准备好读取，但未返回任何数据(设备断开连接？)
Python SerialException:设备报告已准备好读取，但未返回任何数据(设备断开连接？)
提问于 2015-02-05 20:26:02
我有两个Raspberry Pi使用串口和一对XRF无线电互相发送数据。通常它们工作得很好，完整的程序循环多次，但每隔一段时间，其中一个就会停止程序，出现如下错误：
File "BaseListener.py, line 56, in <module>
recieved=serialport.read()
File "/usr/lib/python2.7/dist-packages.serial/serialposix.py", line 465, in read raise SerialException('Device reports readiness to read but returned no data (device disconnected?)')
serial.serialutil.SerialException: device reports readiness to read but returned no data (device disconnected?)我的代码是：
import sys
import serial
import time
import datetime
date = datetime.date.today()
strdate = str(date)
serialport=serial.Serial("/dev/ttyAMA0", 9600, timeout=0.25)
command=''
loop=0
recieving=False
recieving2=False
format = "%Y-%m-%d %H:%M:%S"
while True:
while (recieving==False):
loop = 0
command=''
while (loop<30):
recieved = serialport.read()
command = command + recieved
loop = loop+1
if "DR" in command:
print"DR Recieved"
serialport.write("BSAKAKBS")
recieving=True
while (recieving ==True):
loop = 0
command=''
while (loop<30):
recieved = serialport.read()
command = command + recieved
loop = loop+1
sensorid = command[0:2]
print ("Command: "+command)
print ("SensorID: "+sensorid)
graintemp = command[2:6]
print "GrainTemp Recieved"
serialport.write("BS"+graintemp+"BS")
print (str(graintemp))
loop = 0
command=''
while (loop<30):
recieved = serialport.read()
command = command + recieved
loop = loop+1
if sensorid in command:
if "AK" in command:
print "GrainTemp AK recieved"
serialport.write("BSAKAKBS")
recieving2=True
while (recieving2==True):
loop=0
command=''
while (loop<30):
recieved = serialport.read()
command = command + recieved
loop = loop+1
print ("Command: "+command)
airtemp = command[2:6]
print "AirTemp Signal Recieved"
serialport.write("BS"+airtemp+"BS")
print ("AirTemp: "+str(airtemp))
loop = 0
command=''
while (loop<30):
recieved = serialport.read()
command = command + recieved
loop = loop+1
if sensorid in command:
if "AK" in command:
print ("AK command: ")
print "AirTemp AK Recieved"
serialport.write("BSAKAKBS")
#File Storage
today = datetime.datetime.today()
fulltime = today.strftime(format)
strtime = str(fulltime)
graindata = fulltime + ' ' + graintemp +'\n'
airdata = fulltime + ' ' + airtemp +'\n'
file = open(sensorid+"Graindata.dat", "a")
file.write(graindata)
file.close
file = open(sensorid+"Airdata.dat", "a")
file.write(airdata)
file.close
recieving=False
recieving2=False
loop=0
command=''
graindata=''
airdata=''
graintemp=0
airtemp=0
print "Files stored. Restarting"
else:
print ("IC Command: ")
print "Airtemp IC Recieved"
serialport.write("BSICICBS")
loop = 0
command=''
else:
print "Airtemp ID IC Recieved"
serialport.write("BSICICBS")
loop = 0
command=''
else:
serialport.write("BSICICBS")
print "Graintemp IC Recieved"
loop = 0
command=''
else:
serialport.write("BSICICBS")
print "Graintemp ID IC Recieved"
loop = 0
command=''其他Pi上的代码是相似的(如果需要，我可以提供)。
根据我在网上找到的，这是一些问题，试图读取串行端口，但它是空的。我已经看到了使用try and catch异常的建议，但我不确定这是否会有帮助(或者知道如何做到这一点)。我需要的代码，以连续运行，没有任何干扰，从用户。如果串口是空的，那么AK和IC环路应该会像不正确的传输一样检测到它，所以我只需要它来传递空值。有没有办法做到这一点？
回答 1
Stack Overflow用户
发布于 2020-02-04 16:08:45
使用以下命令：
sudo systemctl stop serial-getty@USB0.service页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/28343941
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