"Grant Edwards" <invalid@invalid.invalid> wrote in message news:jshotj$s55$1...@reader1.panix.com... > On 2012-06-28, Adam <adam@no_thanks.com> wrote: > >> Obviously pySerial considers the serial port open > > Because it's already been opened by the Python program. > >> and will not open an already open serial port. > > Pyserial will happily try if you call the open() of a port that's > already open, but Windows will return an error. > >> However, why is it that TeraTerm can open the serial port? > > Because TeraTerm only opens it once. > >> Here's the link where I read about calling ser.close() before >> ser.open() ... >> >> Trying to open a serial port with pyserial on WinXP -> "Access denied" >> >> http://stackoverflow.com/questions/2063257/trying-to-open-a-serial-port-with-pyserial-on-winxp-access-denied > > That code is broken. > > The port is opened by this line: > > self.ser=serial.Serial(port='\\.\COM1', baudrate=9600, > bytesize=serial.EIGHTBITS, parity=serial.PARITY_NONE, > stopbits=serial.STOPBITS_ONE, timeout=1) > > And then the author tries to _open_it_a_second_time_ here: > > self.ser.open() > >> Here's the Python scripts ... >> https://github.com/adafruit/Tweet-a-Watt/downloads >> Click on the "Download as ..." button for the Python scripts > > Like I kept telling you, those programs are trying to re-open a port > that they've already open. Here's the erroneous code: > > wattcher.py: > > 53 > 54 # open up the FTDI serial port to get data transmitted to xbee > 55 ser = serial.Serial(SERIALPORT, BAUDRATE) > 56 ser.open() > 57 > > Line 55 opens the serial port. > > Line 56 tries to _open_it_again_. _The_port_is_already_open_. > Windows doesn't allow a serial port to be opened twice, therefore the > ser.open() call raises an exception. > > Just delete line 56. > > > The same thing happens here: > > gmeter-wattcher.py > > 83 > 84 # open up the FTDI serial port to get data transmitted to xbee > 85 ser = serial.Serial(SERIALPORT, BAUDRATE) > 86 ser.open() > 87 > > Just delete line 86. > > See how simple it was to get the problem solved once you posted the > actual code? > > -- > Grant Edwards grant.b.edwards Yow! HUMAN REPLICAS are > at inserted into VATS of > gmail.com NUTRITIONAL YEAST ...
Thanks, Grant ! -- http://mail.python.org/mailman/listinfo/python-list
