diff options
Diffstat (limited to 'README.txt')
| -rw-r--r-- | README.txt | 59 |
1 files changed, 48 insertions, 11 deletions
@@ -33,7 +33,7 @@ Features Requirements ------------ -- Python 2.0 or newer (1.5.2 untested) +- Python 2.2 or newer - win32all extensions on Windows - "Java Communications" (JavaComm) extension for Java/Jython @@ -43,8 +43,7 @@ Installation Extract files from the archive, open a shell/console in that directory and let Distutils do the rest: "python setup.py install" -The files get installed in the "Lib/site-packages" directory in newer -Python versions. +The files get installed in the "Lib/site-packages" directory. Serial to USB adapters ---------------------- @@ -80,7 +79,7 @@ Open named port at "19200,8,N,1", 1s timeout >>> 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 +>>> line = ser.readline() #read a '\n' terminated line >>> ser.close() Open second port at "38400,8,E,1", non blocking HW handshaking @@ -89,6 +88,20 @@ Open second port at "38400,8,E,1", non blocking HW handshaking >>> s = ser.read(100) #read up to one hunded bytes ... #or as much is in the buffer +Get a Serial instance and configure/open it later +>>> 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 + Be carefully when using "readline". Do specify a timeout when opening the serial port otherwise it could block forever if no newline character is received. Also note that "readlines" only @@ -100,10 +113,12 @@ if the port is not opened correctly. Parameters for the Serial class ------------------------------- ser = serial.Serial( - port, #number of device, numbering starts at + 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 created baudrate=9600, #baudrate bytesize=EIGHTBITS, #number of databits parity=PARITY_NONE, #enable parity checking @@ -119,15 +134,16 @@ timeout=None #wait forever timeout=0 #non-blocking mode (return immediately on read) timeout=x #set timeout to x seconds (float allowed) -Serial object Methods ---------------------- +Methods of Serial instances +--------------------------- +open() #open port close() #close port immediately setBaudrate(baudrate) #change baudarte on an open port inWaiting() #return the number of chars in the receive buffer read(size=1) #read "size" characters -write(s) #write the string to the port -flushInput() #flush input buffer -flushOutput() #flush output buffer +write(s) #write the string s to the port +flushInput() #flush input buffer, discarding all it's contents +flushOutput() #flush output buffer, abort output sendBreak() #send break condition setRTS(level=1) #set RTS line to specified logic level setDTR(level=1) #set DTR line to specified logic level @@ -136,6 +152,27 @@ getDSR() #return the state of the DSR line getRI() #return the state of the RI line getCD() #return the state of the CD line +Attributes of Serial instances +------------------------------ +Read Only: +portstr #device name +BAUDRATES #list of valid baudrates +BYTESIZES #list of valid byte sizes +PARITIES #list of valid parities +STOPBITS #list of valid stop bit widths + +New values can be assigned to the following attribues, the port +will be reconfigured, even if it's opened at that time: +port #port name/number as set by the user +baudrate #current baudrate setting +bytesize #bytesize in bits +parity #parity setting +stopbits #stop bit with (1,2) +timeout #timeout setting +xonxoff #if XonXoff flow control is enabled +rtscts #if hardware flow control is enabled + + Constants --------- parity: @@ -154,7 +191,7 @@ bytesize: Tips & Tricks ------------- - Some protocols need CR LF ("\r\n") as line terminator, not just LF ("\n"). - Modems are an example of this behaviour. + Telephone modems with the AT command set are an example of this behaviour. - Scanning for available serial ports is possible with more or less sucess on some platforms. Look at the tools from Roger Binns: |