1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
|
#!/usr/bin/env python
#Python Serial Port Extension for Win32, Linux, BSD, Jython
#module for serial IO for POSIX compatible systems, like Linux
#see __init__.py
#
#(C) 2001-2003 Chris Liechti <cliechti@gmx.net>
# this is distributed under a free software license, see license.txt
#
#parts based on code from Grant B. Edwards <grante@visi.com>:
# ftp://ftp.visi.com/users/grante/python/PosixSerial.py
# references: http://www.easysw.com/~mike/serial/serial.html
import sys, os, fcntl, termios, struct, select
from serialutil import *
VERSION = "$Revision: 1.17 $".split()[1] #extract CVS version
#Do check the Python version as some constants have moved.
if (sys.hexversion < 0x020100f0):
import TERMIOS
else:
TERMIOS = termios
if (sys.hexversion < 0x020200f0):
import FCNTL
else:
FCNTL = fcntl
#try to detect the os so that a device can be selected...
plat = sys.platform.lower()
if plat[:5] == 'linux': #Linux (confirmed)
def device(port):
return '/dev/ttyS%d' % port
elif plat == 'cygwin': #cywin/win32 (confirmed)
def device(port):
return '/dev/com%d' % (port + 1)
elif plat == 'openbsd3': #BSD (confirmed)
def device(port):
return '/dev/ttyp%d' % port
elif plat[:3] == 'bsd' or \
plat[:6] == 'netbsd' or \
plat[:7] == 'freebsd' or \
plat[:7] == 'openbsd' or \
plat[:6] == 'darwin': #BSD (confirmed for freebsd4: cuaa%d)
def device(port):
return '/dev/cuaa%d' % port
elif plat[:4] == 'irix': #IRIX® (not tested)
def device(port):
return '/dev/ttyf%d' % port
elif plat[:2] == 'hp': #HP-UX (not tested)
def device(port):
return '/dev/tty%dp0' % (port+1)
elif plat[:5] == 'sunos': #Solaris®/SunOS® (confirmed)
def device(port):
return '/dev/tty%c' % (ord('a')+port)
else:
#platform detection has failed...
info = "sys.platform = %r\nos.name = %r\nserialposix.py version = %s" % (sys.platform, os.name, VERSION)
print """send this information to the author of the pyserial:
%s
also add the device name of the serial port and where the
counting starts for the first serial port.
e.g. 'first serial port: /dev/ttyS0'
and with a bit luck you can get this module running...
"""
#no exception, just continue with a brave attempt to build a device name
#even if the device name is not correct for the platform it has chances
#to work using a string with the real device name as port paramter.
def device(portum):
return '/dev/ttyS%d' % portnum
#~ raise Exception, "this module does not run on this platform, sorry."
#whats up with "aix", "beos", "sco", ....
#they should work, just need to know the device names.
# construct dictionaries for baud rate lookups
baudEnumToInt = {}
baudIntToEnum = {}
for rate in (0,50,75,110,134,150,200,300,600,1200,1800,2400,4800,9600,
19200,38400,57600,115200,230400,460800,500000,576000,921600,
1000000,1152000,1500000,2000000,2500000,3000000,3500000,4000000
):
try:
i = eval('TERMIOS.B'+str(rate))
baudEnumToInt[i]=rate
baudIntToEnum[rate] = i
except:
pass
#load some constants for later use.
#try to use values from TERMIOS, use defaults from linux otherwise
TIOCMGET = hasattr(TERMIOS, 'TIOCMGET') and TERMIOS.TIOCMGET or 0x5415
TIOCMBIS = hasattr(TERMIOS, 'TIOCMBIS') and TERMIOS.TIOCMBIS or 0x5416
TIOCMBIC = hasattr(TERMIOS, 'TIOCMBIC') and TERMIOS.TIOCMBIC or 0x5417
TIOCMSET = hasattr(TERMIOS, 'TIOCMSET') and TERMIOS.TIOCMSET or 0x5418
#TIOCM_LE = hasattr(TERMIOS, 'TIOCM_LE') and TERMIOS.TIOCM_LE or 0x001
TIOCM_DTR = hasattr(TERMIOS, 'TIOCM_DTR') and TERMIOS.TIOCM_DTR or 0x002
TIOCM_RTS = hasattr(TERMIOS, 'TIOCM_RTS') and TERMIOS.TIOCM_RTS or 0x004
#TIOCM_ST = hasattr(TERMIOS, 'TIOCM_ST') and TERMIOS.TIOCM_ST or 0x008
#TIOCM_SR = hasattr(TERMIOS, 'TIOCM_SR') and TERMIOS.TIOCM_SR or 0x010
TIOCM_CTS = hasattr(TERMIOS, 'TIOCM_CTS') and TERMIOS.TIOCM_CTS or 0x020
TIOCM_CAR = hasattr(TERMIOS, 'TIOCM_CAR') and TERMIOS.TIOCM_CAR or 0x040
TIOCM_RNG = hasattr(TERMIOS, 'TIOCM_RNG') and TERMIOS.TIOCM_RNG or 0x080
TIOCM_DSR = hasattr(TERMIOS, 'TIOCM_DSR') and TERMIOS.TIOCM_DSR or 0x100
TIOCM_CD = hasattr(TERMIOS, 'TIOCM_CD') and TERMIOS.TIOCM_CD or TIOCM_CAR
TIOCM_RI = hasattr(TERMIOS, 'TIOCM_RI') and TERMIOS.TIOCM_RI or TIOCM_RNG
#TIOCM_OUT1 = hasattr(TERMIOS, 'TIOCM_OUT1') and TERMIOS.TIOCM_OUT1 or 0x2000
#TIOCM_OUT2 = hasattr(TERMIOS, 'TIOCM_OUT2') and TERMIOS.TIOCM_OUT2 or 0x4000
TIOCINQ = hasattr(TERMIOS, 'FIONREAD') and TERMIOS.FIONREAD or 0x541B
TIOCM_zero_str = struct.pack('I', 0)
TIOCM_RTS_str = struct.pack('I', TIOCM_RTS)
TIOCM_DTR_str = struct.pack('I', TIOCM_DTR)
class Serial(SerialBase):
"""Serial port class POSIX implementation. Serial port configuration is
done with termios and fcntl. Runs on Linux and many other Un*x like
systems."""
def open(self):
"""Open port with current settings. This may throw a SerialException
if the port cannot be opened."""
if self._port is None:
raise SerialException("Port must be configured before it can be used.")
self.fd = None
#open
try:
self.fd = os.open(self.portstr, os.O_RDWR|os.O_NOCTTY|os.O_NONBLOCK)
except Exception, msg:
self.fd = None
raise SerialException("Could not open port: %s" % msg)
fcntl.fcntl(self.fd, FCNTL.F_SETFL, 0) #set blocking
self._reconfigurePort()
self._isOpen = True
def _reconfigurePort(self):
"""Set commuication parameters on opened port."""
if not self.fd:
raise SerialException("Can only operate on a valid port handle")
vmin = vtime = 0 #timeout is done via select
try:
iflag, oflag, cflag, lflag, ispeed, ospeed, cc = termios.tcgetattr(self.fd)
except termios.error, msg: #if a port is nonexistent but has a /dev file, it'll fail here
raise SerialException("Could not configure port: %s" % msg)
#set up raw mode / no echo / binary
cflag |= (TERMIOS.CLOCAL|TERMIOS.CREAD)
lflag &= ~(TERMIOS.ICANON|TERMIOS.ECHO|TERMIOS.ECHOE|TERMIOS.ECHOK|TERMIOS.ECHONL|
TERMIOS.ECHOCTL|TERMIOS.ECHOKE|TERMIOS.ISIG|TERMIOS.IEXTEN) #|TERMIOS.ECHOPRT
oflag &= ~(TERMIOS.OPOST)
if hasattr(TERMIOS, 'IUCLC'):
iflag &= ~(TERMIOS.INLCR|TERMIOS.IGNCR|TERMIOS.ICRNL|TERMIOS.IUCLC|TERMIOS.IGNBRK)
else:
iflag &= ~(TERMIOS.INLCR|TERMIOS.IGNCR|TERMIOS.ICRNL|TERMIOS.IGNBRK)
#setup baudrate
try:
ispeed = ospeed = baudIntToEnum[self._baudrate]
except:
raise ValueError('Invalid baud rate: %r' % self._baudrate)
#setup char len
cflag &= ~TERMIOS.CSIZE
if self._bytesize == 8:
cflag |= TERMIOS.CS8
elif self._bytesize == 7:
cflag |= TERMIOS.CS7
elif self._bytesize == 6:
cflag |= TERMIOS.CS6
elif self._bytesize == 5:
cflag |= TERMIOS.CS5
else:
raise ValueError('Invalid char len: %r' % self._bytesize)
#setup stopbits
if self._stopbits == STOPBITS_ONE:
cflag &= ~(TERMIOS.CSTOPB)
elif self._stopbits == STOPBITS_TWO:
cflag |= (TERMIOS.CSTOPB)
else:
raise ValueError('Invalid stopit specification: %r' % self._stopbits)
#setup parity
iflag &= ~(TERMIOS.INPCK|TERMIOS.ISTRIP)
if self._parity == PARITY_NONE:
cflag &= ~(TERMIOS.PARENB|TERMIOS.PARODD)
elif self._parity == PARITY_EVEN:
cflag &= ~(TERMIOS.PARODD)
cflag |= (TERMIOS.PARENB)
elif self._parity == PARITY_ODD:
cflag |= (TERMIOS.PARENB|TERMIOS.PARODD)
else:
raise ValueError('Invalid parity: %r' % self._parity)
#setup flow control
#xonxoff
if hasattr(TERMIOS, 'IXANY'):
if self._xonxoff:
iflag |= (TERMIOS.IXON|TERMIOS.IXOFF|TERMIOS.IXANY)
else:
iflag &= ~(TERMIOS.IXON|TERMIOS.IXOFF|TERMIOS.IXANY)
else:
if self._xonxoff:
iflag |= (TERMIOS.IXON|TERMIOS.IXOFF)
else:
iflag &= ~(TERMIOS.IXON|TERMIOS.IXOFF)
#rtscts
if hasattr(TERMIOS, 'CRTSCTS'):
if self._rtscts:
cflag |= (TERMIOS.CRTSCTS)
else:
cflag &= ~(TERMIOS.CRTSCTS)
elif hasattr(TERMIOS, 'CNEW_RTSCTS'): #try it with alternate constant name
if self._rtscts:
cflag |= (TERMIOS.CNEW_RTSCTS)
else:
cflag &= ~(TERMIOS.CNEW_RTSCTS)
#XXX should there be a warning if setting up rtscts (and xonxoff etc) fails??
#buffer
#vmin "minimal number of characters to be read. = for non blocking"
if vmin < 0 or vmin > 255:
raise ValueError('Invalid vmin: %r ' % vmin)
cc[TERMIOS.VMIN] = vmin
#vtime
if vtime < 0 or vtime > 255:
raise ValueError('Invalid vtime: %r' % vtime)
cc[TERMIOS.VTIME] = vtime
#activate settings
termios.tcsetattr(self.fd, TERMIOS.TCSANOW, [iflag, oflag, cflag, lflag, ispeed, ospeed, cc])
def close(self):
"""Close port"""
if self._isOpen:
if self.fd:
os.close(self.fd)
self.fd = None
self._isOpen = False
def makeDeviceName(self, port):
return device(port)
# - - - - - - - - - - - - - - - - - - - - - - - -
def inWaiting(self):
"""Return the number of characters currently in the input buffer."""
#~ s = fcntl.ioctl(self.fd, TERMIOS.FIONREAD, TIOCM_zero_str)
s = fcntl.ioctl(self.fd, TIOCINQ, TIOCM_zero_str)
return struct.unpack('I',s)[0]
def read(self, size=1):
"""Read size bytes from the serial port. If a timeout is set it may
return less characters as requested. With no timeout it will block
until the requested number of bytes is read."""
if not self.fd: raise portNotOpenError
read = ''
inp = None
if size > 0:
while len(read) < size:
#print "\tread(): size",size, "have", len(read) #debug
ready,_,_ = select.select([self.fd],[],[], self.timeout)
if not ready:
break #timeout
buf = os.read(self.fd, size-len(read))
read = read + buf
if self.timeout >= 0 and not buf:
break #early abort on timeout
return read
def write(self, data):
"""Output the given string over the serial port."""
if not self.fd: raise portNotOpenError
t = len(data)
d = data
while t>0:
n = os.write(self.fd, d)
d = d[n:]
t = t - n
def flushInput(self):
"""Clear input buffer, discarding all that is in the buffer."""
if not self.fd:
raise portNotOpenError
termios.tcflush(self.fd, TERMIOS.TCIFLUSH)
def flushOutput(self):
"""Clear output buffer, aborting the current output and
discarding all that is in the buffer."""
if not self.fd:
raise portNotOpenError
termios.tcflush(self.fd, TERMIOS.TCOFLUSH)
def sendBreak(self):
"""Send break condition."""
if not self.fd:
raise portNotOpenError
termios.tcsendbreak(self.fd, 0)
def setRTS(self,on=1):
"""Set terminal status line: Request To Send"""
if not self.fd: raise portNotOpenError
if on:
fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_RTS_str)
else:
fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_RTS_str)
def setDTR(self,on=1):
"""Set terminal status line: Data Terminal Ready"""
if not self.fd: raise portNotOpenError
if on:
fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_DTR_str)
else:
fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_DTR_str)
def getCTS(self):
"""Read terminal status line: Clear To Send"""
if not self.fd: raise portNotOpenError
s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
return struct.unpack('I',s)[0] & TIOCM_CTS != 0
def getDSR(self):
"""Read terminal status line: Data Set Ready"""
if not self.fd: raise portNotOpenError
s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
return struct.unpack('I',s)[0] & TIOCM_DSR != 0
def drainOutput(self):
"""internal - not portable!"""
if not self.fd: raise portNotOpenError
termios.tcdrain(self.fd)
def nonblocking(self):
"""internal - not portable!"""
if not self.fd:
raise portNotOpenError
fcntl.fcntl(self.fd, FCNTL.F_SETFL, FCNTL.O_NONBLOCK)
def getRI(self):
"""Read terminal status line: Ring Indicator"""
if not self.fd: raise portNotOpenError
s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
return struct.unpack('I',s)[0] & TIOCM_RI != 0
def getCD(self):
"""Read terminal status line: Carrier Detect"""
if not self.fd: raise portNotOpenError
s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
return struct.unpack('I',s)[0] & TIOCM_CD != 0
if __name__ == '__main__':
s = Serial(0,
baudrate=19200, #baudrate
bytesize=EIGHTBITS, #number of databits
parity=PARITY_EVEN, #enable parity checking
stopbits=STOPBITS_ONE, #number of stopbits
timeout=3, #set a timeout value, None for waiting forever
xonxoff=0, #enable software flow control
rtscts=0, #enable RTS/CTS flow control
)
s.setRTS(1)
s.setDTR(1)
s.flushInput()
s.flushOutput()
s.write('hello')
print repr(s.read(5))
print s.inWaiting()
del s
|