def set_buffer_size(self, rx_size=4096, tx_size=None):
"""\
Recommend a buffer size to the driver (device driver can ignore this
value). Must be called after the port is opened.
"""
if tx_size is None:
tx_size = rx_size
win32.SetupComm(self._port_handle, rx_size, tx_size)
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.")
if self._isOpen:
raise SerialException("Port is already open.")
# the "\\.\COMx" format is required for devices other than COM1-COM8
# not all versions of windows seem to support this properly
# so that the first few ports are used with the DOS device name
port = self.portstr
try:
if port.upper().startswith('COM') and int(port[3:]) > 8:
port = '\\\\.\\' + port
except ValueError:
# for like COMnotanumber
pass
self.hComPort = win32.CreateFile(
port,
win32.GENERIC_READ | win32.GENERIC_WRITE,
0, # exclusive access
None, # no security
win32.OPEN_EXISTING,
win32.FILE_ATTRIBUTE_NORMAL | win32.FILE_FLAG_OVERLAPPED,
0)
if self.hComPort == win32.INVALID_HANDLE_VALUE:
self.hComPort = None # 'cause __del__ is called anyway
raise SerialException("could not open port %s: %s" %
(self.portstr, ctypes.WinError()))
# Setup a 4k buffer
win32.SetupComm(self.hComPort, 4096, 4096)
# Save original timeout values:
self._orgTimeouts = win32.COMMTIMEOUTS()
win32.GetCommTimeouts(self.hComPort, ctypes.byref(self._orgTimeouts))
self._rtsState = win32.RTS_CONTROL_ENABLE
self._dtrState = win32.DTR_CONTROL_ENABLE
self._reconfigurePort()
# Clear buffers:
# Remove anything that was there
win32.PurgeComm(
self.hComPort, win32.PURGE_TXCLEAR | win32.PURGE_TXABORT
| win32.PURGE_RXCLEAR | win32.PURGE_RXABORT)
self._overlappedRead = win32.OVERLAPPED()
self._overlappedRead.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlappedWrite = win32.OVERLAPPED()
#~ self._overlappedWrite.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlappedWrite.hEvent = win32.CreateEvent(None, 0, 0, None)
self._isOpen = True
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.")
if self.is_open:
raise SerialException("Port is already open.")
# if RTS and/or DTR are not set before open, they default to True
if self._rts_state is None:
self._rts_state = True
if self._dtr_state is None:
self._dtr_state = True
# the "\\.\COMx" format is required for devices other than COM1-COM8
# not all versions of windows seem to support this properly
# so that the first few ports are used with the DOS device name
port = self.name
try:
if port.upper().startswith('COM') and int(port[3:]) > 8:
port = '\\\\.\\' + port
except ValueError:
# for like COMnotanumber
pass
self._port_handle = win32.CreateFile(
port,
win32.GENERIC_READ | win32.GENERIC_WRITE,
0, # exclusive access
None, # no security
win32.OPEN_EXISTING,
win32.FILE_ATTRIBUTE_NORMAL | win32.FILE_FLAG_OVERLAPPED,
0)
if self._port_handle == win32.INVALID_HANDLE_VALUE:
self._port_handle = None # 'cause __del__ is called anyway
raise SerialException("could not open port {!r}: {!r}".format(
self.portstr, ctypes.WinError()))
try:
self._overlapped_read = win32.OVERLAPPED()
self._overlapped_read.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlapped_write = win32.OVERLAPPED()
#~ self._overlapped_write.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlapped_write.hEvent = win32.CreateEvent(None, 0, 0, None)
# Setup a 4k buffer
win32.SetupComm(self._port_handle, 4096, 4096)
# Save original timeout values:
self._orgTimeouts = win32.COMMTIMEOUTS()
win32.GetCommTimeouts(self._port_handle,
ctypes.byref(self._orgTimeouts))
self._reconfigure_port()
# Clear buffers:
# Remove anything that was there
win32.PurgeComm(
self._port_handle, win32.PURGE_TXCLEAR | win32.PURGE_TXABORT
| win32.PURGE_RXCLEAR | win32.PURGE_RXABORT)
except:
try:
self._close()
except:
# ignore any exception when closing the port
# also to keep original exception that happened when setting up
pass
self._port_handle = None
raise
else:
self.is_open = True
win32.OPEN_EXISTING,
win32.FILE_ATTRIBUTE_NORMAL | win32.FILE_FLAG_OVERLAPPED,
0)
if self._port_handle == win32.INVALID_HANDLE_VALUE:
self._port_handle = None # 'cause __del__ is called anyway
raise SerialException("could not open port {!r}: {!r}".format(self.portstr, ctypes.WinError()))
try:
self._overlapped_read = win32.OVERLAPPED()
self._overlapped_read.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlapped_write = win32.OVERLAPPED()
#~ self._overlapped_write.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlapped_write.hEvent = win32.CreateEvent(None, 0, 0, None)
# Setup a 4k buffer
win32.SetupComm(self._port_handle, 4096, 4096)
# Save original timeout values:
self._orgTimeouts = win32.COMMTIMEOUTS()
win32.GetCommTimeouts(self._port_handle, ctypes.byref(self._orgTimeouts))
self._reconfigure_port()
# Clear buffers:
# Remove anything that was there
win32.PurgeComm(
self._port_handle,
win32.PURGE_TXCLEAR | win32.PURGE_TXABORT |
win32.PURGE_RXCLEAR | win32.PURGE_RXABORT)
except:
try: