Big Red Button - playing sounds on Windows

button.py

import sys
import time
import usb
import winsound

"""
Using the MetricFire "Big Red Button" to play buzzer sounds.
Buzzer sounds should be WAV files.

Gonna need to follow the driver installation instructions here:
http://www.libusb.org/wiki/windows_backend#DriverInstallation
Use libusb-win32

Oh and of course, Python.

"""

class Button:
   def __init__(self, vendor_id, device_id):
      """
      Find and open a USB HID device.
      """
      
      self.vendor_id = vendor_id
      self.device_id = device_id
      self.endpoint = 0x81

      self.device = self.getDevice(vendor_id, device_id)
      
      if self.device == None:
         raise DeviceNotFound, "No recognised device connected."

      self.handle = self.openDevice(self.device)
   
   def __del__(self):
      """
      Releases the device.
      """
      try:
         self.handle.releaseInterface()
         del self.handle
      except:
         pass
   
   def getDevice(self, vendor_id, device_id):
      """
      Searches the USB buses for a device matching the given vendor and device IDs.

      Returns a usb.Device, or None if the device cannot be found.
      """      

      busses = usb.busses()
   
      for bus in busses:
         devices = bus.devices
         for device in devices:
            if device.idVendor == vendor_id and device.idProduct == device_id:
               return device
   
      return None
   
   def openDevice(self, device):
      """
      Opens and claims the specified device. Returns a usb.DeviceHandle

      Also attempts to detach the kernel's driver from the device, if necessary.
      """

      handle = device.open()

      # Attempt to remove other drivers using this device. This is necessary
      # for HID devices.
      try:
         handle.detachKernelDriver(0)
      except:
         pass # Ignore failures here, the device might already be detached.

      handle.claimInterface(0)
      
      return handle

   def buzz(self, sound="default"):
      winsound.PlaySound("%s.wav" % sound, winsound.SND_FILENAME)

   def on_keydown(self):
      print "keydown event"
      self.buzz()

   def on_keyup(self):
      print "keyup event"

   def start(self):
      data = None
      while True:
         try:
            data = self.handle.interruptRead(self.endpoint, 8, 0).tolist()
         except:
            raise

         if data == [0, 0, 88, 0, 0, 0, 0, 0]: # numeric keypad enter pressed
            self.on_keydown()
         elif data == [0, 0, 0, 0, 0, 0, 0, 0]:
            self.on_keyup()
         
         data = None

class DeviceNotFound(Exception):
 def __init__(self,value):
    self.value = value
 def __str__(self):
    return repr(self.value)

if __name__ == "__main__":
   button = Button(0x1710, 0x5612)
   button.start()