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发布时间：2022-04-19 13:53
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时间：2022-04-18 21:51
串口模块的波特率比较特别，找了几个串口工具都不支持。。。所以，干脆用python自己来写了，其实已经好奇好久了，别人的工具各种不顺手。
需要pyserial的支持，兼容各种平台，不需要新编译二进制文件。
先贴一个定时发送的代码：
import serialimport time
ser = serial.Serial('/dev/ttyUSB0', 250000, timeout=1)print ser.isOpen()
words="gggggggggggggggg"while (1): print "send 256x\""+words+"\" to remotes"
startTime = time.time()
times = 256 while (times):
times -= 1
s = ser.write(words)
endTime = time.time() print "use time: "+str(endTime-startTime) print ""
time.sleep(5)
ser.close()
然后是一些其它的方法：
1. 使用序号打开串口：ser = serial.Serial(0) 。but，怎么确定串口的序号？？？
2. 查看串口的名称，啊哈，用1的方法打开串口后，你可以产看串口的名字：print ser.portstr
3. 先例化一个实体，再打开：
>>> ser = serial.Serial()>>> ser.baudrate = 19200
>>> ser.port = 0>>> ser
Serial<id=0xa81c10, open=False>(port='COM1', baudrate=19200, bytesize=8, parity='N', stopbits=1, timeout=None, xonxoff=0, rtscts=0)>>> ser.open()>>> ser.isOpen()
True>>> ser.close()>>> ser.isOpen()
False
好多人问 windows 下面提示设备不存在！亲，windows 下面的串口设备名不一样的啊，上面的代码里面 COM1 就是 windows 下面的设备。
4. 读取数据的几种方式
>>> ser = serial.Serial('/dev/ttyS1', 19200, timeout=1)>>> x = ser.read() # read one byte>>> s = ser.read(10) # read up to ten bytes (timeout)>>> line = ser.readline() # read a '/n' terminated line>>> ser.close()
其中，如果只是串口调试，直接ser.read(1000)，这样会把读到的值直接打印到屏幕上。
5.所有参数
ser = serial.Serial(
port=None, # number of device, numbering starts at# zero. if everything fails, the user# can specify a device string, note# that this isn't portable anymore# if no port is specified an unconfigured# an closed serial port object is createdbaudrate=9600, # baud ratebytesize=EIGHTBITS, # number of databitsparity=PARITY_NONE, # enable parity checkingstopbits=STOPBITS_ONE, # number of stopbitstimeout=None, # set a timeout value, None for waiting foreverxonxoff=0, # enable software flow controlrtscts=0, # enable RTS/CTS flow controlinterCharTimeout=None # Inter-character timeout, None to disable)
6. exception：serial.SerialException
另一个完整收发的例子，单片机数据以TLV（Type，Length，Value）格式发上来
#!/usr/bin/env python
# it's a program of luo, piedgogo@sina.com
import serialimport arrayimport osimport signalfrom time import sleep
flag_stop = Falsedef onsignal_int(a,b): print "sigint!"
global flag_stop
flag_stop = True
signal.signal(signal.SIGINT, onsignal_int)
signal.signal(signal.SIGTERM, onsignal_int)
ser = serial.Serial('/dev/ttyUSB0', 9600, timeout = 0.001)print "serial.isOpen() =",ser.isOpen()
cmd_send = "7b02000129cc00c80378290400640000cc7d0d0a"cmd_send = cmd_send.decode("hex")
stop = "7b04047d0d0a"stop = stop.decode("hex")
cmd_back = ""cmd_length = 0x00cmd_count = 0x00s = ser.write(cmd_send)while True:
sleep(0.1)
if flag_stop: # read data until Ctrl+c
ser.write(stop) # send cmd stop before exit
print "reset cmd has been sent!"
sleep(0.05) break
text = ser.read(1) # read one, with timout
if text: # check if not timeout
n = ser.inWaiting() # look if there is more to read
if n:
text = text + ser.read(n) #get it
cmd_back = cmd_back + text
text = ""
if len(cmd_back) < 2: # go back if no enough data recvd
continue
if cmd_length == 0x00: # new loop
cmd_length = ord(cmd_back[1]) # Type(1 byte),Length of Value(1 byte),Value
print "new cmd length,",cmd_length
if (cmd_length + 0x02) > len(cmd_back): # do nothing until all bytes is recvd
continue
# so far, we have got a full cmd
hex_list = [hex(ord(i)) for i in cmd_back] # more readable than data.encode("hex")
print "In buffer:",hex_list
cmd_back = cmd_back[cmd_length+2:] # remove this cmd(TLV) from buffer
cmd_length = 0
cmd_count += 1
print "==> %d cmds recvd."%(cmd_count) print "-------------"
ser.close()
——————