USB2 Stick Driver

buildout.cfg

@@ -7,6 +7,7 @@ parts =
     pep8
     importchecker
     sphinx
+    pyusb
 develop = .
 eggs = ant
 
@@ -48,3 +49,9 @@ recipe = zc.recipe.egg
 eggs =
     ${buildout:eggs}
     sphinx
+
+[pyusb]
+recipe = zc.recipe.egg
+eggs =
+    ${buildout:eggs}
+    pyusb

demos/ant.core/02-capabilities-USB.py

@@ -0,0 +1,30 @@
+"""
+Interrogate stick for supported capabilities.
+
+"""
+
+import sys
+
+from ant.core import driver
+from ant.core import node
+
+from config import *
+
+# Initialize
+stick = driver.USB2Driver(SERIAL, log=LOG, debug=DEBUG)
+antnode = node.Node(stick)
+antnode.start()
+
+# Interrogate stick
+# Note: This method will return immediately, as the stick's capabilities are
+# interrogated on node initialization (node.start()) in order to set proper
+# internal Node instance state.
+capabilities = antnode.getCapabilities()
+
+print 'Maximum channels:', capabilities[0]
+print 'Maximum network keys:', capabilities[1]
+print 'Standard options: %X' % capabilities[2][0]
+print 'Advanced options: %X' % capabilities[2][1]
+
+# Shutdown
+antnode.stop()

setup.py

@@ -58,6 +58,7 @@ def read(fname):
     install_requires=[
         'distribute',
         'pyserial',
+        'pyusb',
         'msgpack-python'
     ],
 )

src/ant/core/driver.py

@@ -25,10 +25,16 @@
 
 import thread
 
+# USB1 driver uses a USB<->Serial bridge
 import serial
+# USB2 driver uses direct USB connection. Requires PyUSB
+import usb.core
+import usb.util
 
 from ant.core.exceptions import DriverError
 
+from array import *
+
 
 class Driver(object):
     _lock = thread.allocate_lock()
@@ -173,3 +179,59 @@ def _write(self, data):
             raise DriverError(str(e))
 
         return count
+
+
+class USB2Driver(Driver):
+    def _open(self):
+        # Most of this is straight from the PyUSB example documentation		
+        dev = usb.core.find(idVendor=0x0fcf, idProduct=0x1008)
+
+        if dev is None:
+            raise DriverError('Could not open device (not found)')
+        dev.set_configuration()
+        cfg = dev.get_active_configuration()
+        interface_number = cfg[(0,0)].bInterfaceNumber
+        alternate_setting = usb.control.get_interface(dev, interface_number)
+        intf = usb.util.find_descriptor(
+            cfg, bInterfaceNumber = interface_number,
+            AlternateSetting = alternate_setting
+        )
+        usb.util.claim_interface(dev, interface_number)
+        ep_out = usb.util.find_descriptor(
+            intf,
+            custom_match = \
+            lambda e: \
+                usb.util.endpoint_direction(e.bEndpointAddress) == \
+                usb.util.ENDPOINT_OUT
+        )
+        assert ep_out is not None
+        ep_in = usb.util.find_descriptor(
+            intf,
+            custom_match = \
+            lambda e: \
+                usb.util.endpoint_direction(e.bEndpointAddress) == \
+                usb.util.ENDPOINT_IN
+        )
+        assert ep_in is not None
+        self._ep_out = ep_out
+        self._ep_in = ep_in
+        self._dev = dev
+        self._int = interface_number
+
+    def _close(self):
+        usb.util.release_interface(self._dev, self._int)
+
+    def _read(self, count):
+        arr_inp = array('B')
+        try:
+            arr_inp = self._ep_in.read(count)
+        except usb.core.USBError:
+            # Timeout errors seem to occasionally be expected
+            pass
+
+        return arr_inp.tostring()
+
+    def _write(self, data):
+        count = self._ep_out.write(data)
+
+        return count