Python serial

Posted 2020-10-15 njuptlwh

__init__(port=None, baudrate=9600, bytesize=EIGHTBITS, parity=PARITY_NONE, stopbits=STOPBITS_ONE, timeout=None, xonxoff=False, rtscts=False, write_timeout=None, dsrdtr=False, inter_byte_timeout=None)

Parameters:

• port – Device name or None.
• baudrate (int) – Baud rate such as 9600 or 115200 etc.
• bytesize – Number of data bits. Possible values: FIVEBITS, SIXBITS, SEVENBITS, EIGHTBITS
• parity – Enable parity checking. Possible values: PARITY_NONE, PARITY_EVEN, PARITY_ODD PARITY_MARK, PARITY_SPACE
• stopbits – Number of stop bits. Possible values: STOPBITS_ONE, STOPBITS_ONE_POINT_FIVE, STOPBITS_TWO
• timeout (float) – Set a read timeout value.
• xonxoff (bool) – Enable software flow control.
• rtscts (bool) – Enable hardware (RTS/CTS) flow control.
• dsrdtr (bool) – Enable hardware (DSR/DTR) flow control.
• write_timeout (float) – Set a write timeout value.
• inter_byte_timeout (float) – Inter-character timeout, None to disable (default).

Raises:

• ValueError – Will be raised when parameter are out of range, e.g. baud rate, data bits.
• SerialException – In case the device can not be found or can not be configured.

 1 import serial
 2 import time
 3 
 4 
 5 # initialize the serial ports
 6 t = serial.Serial(‘com9‘,9600,timeout = 0.1)
 7 #write commond list, commond should be ended with ‘\n‘ or ‘\r‘
 8 cmd_list = [‘val?\r‘,‘temp?\r‘]
 9 a = ‘‘
10 
11 #t.close() # close port
12 #t.open() # open port
13 
14 print t.portstr #print port number
15 for idx2 in cmd_list:
16     n = t.write(idx2)
17     #print n  #
18     #s1 = t.readall()
19     s1 = t.readline()
20     #s1 = t.readlines()
21     print s1
22 
23 #t = serial.Serial(‘com8‘,9600,timeout = 0.1)
24 #for idx1 in cmd_list:
25 #    t.write(idx1)
26 #    start = time.clock()
27 #    while(True):
28 #        s = t.read(1)
29 #        a = a + s
30 #        if(str(s) == ‘\r‘):
31 #            break
32 #        now = time.clock()
33 #        if(now - start) > 2:
34 #            print ‘timeout‘
35 #            break
36 #    print a
37 #    a = ‘‘
38 
39 t.close()