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我正在尝试使用 Python 2.7 和 PySerial 同时读取多个串行端口。
特征应该是:
- 在主程序中，我获取所有打开的串行端口，打开它们并将串行对象附加到 serialobjects
- 我想在一个子进程中并行读取每个串口数据
最大的问题是:如何将串口对象传递给子进程？
或者:
是否存在另一个(也许更好)的解决方案？
(可能是 this:如何将双绞串口应用于我的问题？)
编辑
我想我并不完全清楚我想要实现的目标。
我想同时读出2个或多个串口。由于超时和读出时间，不可能在一个进程中同时读出它们。
下面的做法
ser1 = serial.Serial(port="COM1",baudrate=9600)
ser2 = serial.Serial(port="COM2",baudrate=9600)
ser1.write('command for reading out device 1')
output1 = ser1.readline()
ser2.write('command for reading out device 2')
# now you have to wait at least 100ms for device 2 to respond
output2 = ser2.readline()
不满足我的需求。
另一种方法是并行化子进程中的串行读数。
主.py
import serial # serial communication
from subprocess import Popen, PIPE
ports = ["COM1", "COM2"]
for port in ports:
ser = serial.Serial()
ser.port=port
ser.baudrate=9600
# set parity and ...
serialobjects.append(ser)
# call subprocess
# pass the serial object to subprocess
# read out serial port
# HOW TO PASS SERIAL OBJECT HERE to stdin
p1 = Popen(['python', './ReadCOM.py'], stdin=PIPE, stdout=PIPE, stderr=PIPE) # read COM1 permanently
p2 = Popen(['python', './ReadCOM.py'], stdin=PIPE, stdout=PIPE, stderr=PIPE) # read COM2 permanently
for i in range(10):
print "received from COM1: %s" % p1.stdout.readline() # print output from ReadCOM.py for COM1
print "received from COM2: %s" % p2.stdout.readline() # print output from ReadCOM.py for COM2
ReadCOM.py(取自 related post 并编辑)
import sys
while True: # The program never ends... will be killed when master is over.
# sys.stdin.readline()
ser.write('serial command here\n') # send command to serial port
output = ser.readline() # read output
sys.stdout.write(output) # write output to stdout
sys.stdout.flush()
import serial # serial communication
from subprocess import Popen, PIPE
ports = ["COM1", "COM2"]
for port in ports:
ser = serial.Serial()
ser.port=port
ser.baudrate=9600
# set parity and ...
serialobjects.append(ser)
# call subprocess
# pass the serial object to subprocess
# read out serial port
# HOW TO PASS SERIAL OBJECT HERE to stdin
p1 = Popen(['python', './ReadCOM.py'], stdin=PIPE, stdout=PIPE, stderr=PIPE) # read COM1 permanently
p2 = Popen(['python', './ReadCOM.py'], stdin=PIPE, stdout=PIPE, stderr=PIPE) # read COM2 permanently
for i in range(10):
print "received from COM1: %s" % p1.stdout.readline() # print output from ReadCOM.py for COM1
print "received from COM2: %s" % p2.stdout.readline() # print output from ReadCOM.py for COM2
import sys
while True: # The program never ends... will be killed when master is over.
# sys.stdin.readline()
ser.write('serial command here\n') # send command to serial port
output = ser.readline() # read output
sys.stdout.write(output) # write output to stdout
sys.stdout.flush()
提前致谢!