1, need modules and test tools
Module name: pyserial
Download with the command: python -m pip install pyserial
Serial debugging tool: sscom5.13.
2、Import Module
import serial
3. Open the serial port
It can be opened directly by creating an instance of Serial().
Return Example
# encoding=utf-8
import serial
if __name__ == '__main__':
com = ('COM3', 115200)
print com
running result
Serial<id=0x3518940, open=True>(port='COM3', baudrate=115200, bytesize=8, parity='N', stopbits=1, timeout=None, xonxoff=False, rtscts=False, dsrdtr=False)
4、Send data
Function name write()
The return value is the number of bytes sent successfully
# encoding=utf-8
import serial
if __name__ == '__main__':
com = ('COM3', 115200)
success_bytes = ('This is data for test')
print success_bytes
running result
21
Serial Tools Interface
5. Receiving data (receiving fixed-length data)
The function is called read(size=1)
Characters received in size units are blocked and wait to be received until they are received, unless a timeout is set (this example is not set)
# encoding=utf-8
import serial
if __name__ == '__main__':
com = ('COM3', 115200)
data = (10)
print data
running result
123456789a
Serial Tools Interface
6. Receive data (always receive within the timeout period)
The function is called read(size=1)
The parameter is the length of the received string, default is 1, usually pass inWaiting(), it means monitoring the length of the received string.
With While you can always receive
# encoding=utf-8
import serial
import time
if __name__ == '__main__':
com = ('COM3', 115200)
over_time = 30
start_time = ()
while True:
end_time = ()
if end_time - start_time < over_time:
data = (())
data = str(data)
if data != '':
print data
running result
111
222
aaa
bbb
1a2b3c4d
Serial Tools Interface
7. Encapsulation into classes
# -*- encoding=utf-8 -*-
import serial
import time
import WriteLog
class COM:
def __init__(self, port, baud):
= port
= int(baud)
self.open_com = None
= ('ITC_LOG.LOG')
self.get_data_flag = True
self.real_time_data = ''
# return real time data form com
def get_real_time_data(self):
return self.real_time_data
def clear_real_time_data(self):
self.real_time_data = ''
# set flag to receive data or not
def set_get_data_flag(self, get_data_flag):
self.get_data_flag = get_data_flag
def open(self):
try:
self.open_com = (, )
except Exception as e:
('Open com fail:{}/{}'.format(, ))
('Exception:{}'.format(e))
def close(self):
if self.open_com is not None and self.open_com.isOpen:
self.open_com.close()
def send_data(self, data):
if self.open_com is None:
()
success_bytes = self.open_com.write(('UTF-8'))
return success_bytes
def get_data(self, over_time=30):
all_data = ''
if self.open_com is None:
()
start_time = ()
while True:
end_time = ()
if end_time - start_time < over_time and self.get_data_flag:
data = self.open_com.read(self.open_com.inWaiting())
# data = self.open_com.read() # read 1 size
data = str(data)
if data != '':
('Get data is:{}'.format(data))
all_data = all_data + data
print data
self.real_time_data = all_data
else:
self.set_get_data_flag(True)
break
return all_data
if __name__ == '__main__':
pass
com = COM('com3', 115200)
# ()
print com.send_data('data')
com.get_data(50)
()
8, for the primary function description (Baidu see, did not test)
readall(): read all characters, is blocking, unless the received string ends in EOF or exceeds the buffer, the function will not return. Generally, you need to set the timeout parameter of the serial port.
Readline(): read a line, end with /n, if there is no /n, keep reading, blocking.
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