diff --git a/mbed_lstools/lstools_darwin.py b/mbed_lstools/lstools_darwin.py
index 5c179ed..1bc3412 100644
--- a/mbed_lstools/lstools_darwin.py
+++ b/mbed_lstools/lstools_darwin.py
@@ -96,16 +96,26 @@ def get_mbed_volumes(self):
         ''' returns a map {volume_id: {serial:, vendor_id:, product_id:, tty:}'''
 
         # to find all the possible mbed volumes, we look for registry entries
-        # under the USB bus which have a "BSD Name" that starts with "disk"
+        # under all possible USB bus which have a "BSD Name" that starts with "disk"
         # (i.e. this is a USB disk), and have a IORegistryEntryName that
         # matches /\cmbed/
         # Once we've found a disk, we can search up for a parent with a valid
         # serial number, and then search down again to find a tty that's part
         # of the same composite device
-        # ioreg -a -r -n "AppleUSBXHCI" -l
-        ioreg_usb = subprocess.Popen(['ioreg', '-a', '-r', '-n', 'AppleUSBXHCI', '-l'], stdout=subprocess.PIPE)
-        usb_bus = plistlib.readPlist(ioreg_usb.stdout)
-        ioreg_usb.wait()
+        # ioreg -a -r -n <usb_controller_name> -l
+        usb_controllers = ['AppleUSBXHCI', 'AppleUSBUHCI', 'AppleUSBEHCI', 'AppleUSBOHCI']
+        usb_bus = []
+
+        for usb_controller in usb_controllers:	
+            ioreg_usb = subprocess.Popen(['ioreg', '-a', '-r', '-n', usb_controller, '-l'], stdout=subprocess.PIPE)
+            
+	    try:
+                usb_bus = usb_bus + plistlib.readPlist(ioreg_usb.stdout)
+	    except:
+		# Catch when no output is returned from ioreg command
+                pass
+
+            ioreg_usb.wait()
 
         r = {}