def getSerialHandlerForPort(port): """ Return a constructed and started SerialHandler for a port. :param port: A serial port name :return: A SerialHandler instance """ serialHandler = SerialHandler() serialHandler.openPort(port) serialHandler.start() return serialHandler
def __init__(self, port, addDeviceCallback): threading.Thread.__init__(self) self.daemon = True self.port = port self.serialHandler = SerialHandler() self.messages = queue.Queue() self.addDeviceCallback = addDeviceCallback
class DeviceQueryThread(threading.Thread):
""" Support class for identifying the type of device on a port """
timeoutInSeconds = 0.5
def __init__(self, port, addDeviceCallback):
threading.Thread.__init__(self)
self.daemon = True
self.port = port
self.serialHandler = SerialHandler()
self.messages = queue.Queue()
self.addDeviceCallback = addDeviceCallback
def run(self):
try:
self.serialHandler.openPort(self.port[0])
self.serialHandler.start()
except (SerialPortLocked, BlockingIOError) as exception:
# ignore locked port errors, devices may already be open
return
except IOError:
logger.exception("Failed to open port %s", self.port)
return
try:
device = PractichemSerialDevice(None, self.serialHandler)
deviceInfo = {portId: self.port[0]}
deviceInfo[productNameId] = device.getProductName()
deviceInfo[productNumberId] = device.getProductNumber()
deviceInfo[firmwareVersionId] = device.getFirmwareVersion()
deviceInfo[firmwareBuildDateId] = device.getFirmwareBuildDate()
deviceInfo[uuidId] = device.getUuid()
self.addDeviceCallback(deviceInfo)
except (IOError, queue.Empty):
# the device had a valid Practichem CDC VID:PID combination, failure means the device is not functioning
logger.error("Practichem device not found on %s", self.port)
finally:
device.shutdown()
# need to wait for the serial handler to shutdown to free the port, otherwise the
# main application will fail trying to open the port
self.serialHandler.join(10)