diff --git a/usb/usb.go b/usb/usb.go
index 36f3be0..b3e3d3f 100644
--- a/usb/usb.go
+++ b/usb/usb.go
@@ -20,6 +20,14 @@ const SPEED_FULL = C.LIBUSB_SPEED_FULL
 const SPEED_HIGH = C.LIBUSB_SPEED_HIGH
 const SPEED_SUPER = C.LIBUSB_SPEED_SUPER
 
+var SPEED_names = map[byte]string{
+	byte(C.LIBUSB_SPEED_UNKNOWN): "UNKNOWN",
+	byte(C.LIBUSB_SPEED_LOW): "LOW",
+	byte(C.LIBUSB_SPEED_FULL): "FULL",
+	byte(C.LIBUSB_SPEED_HIGH): "HIGH",
+	byte(C.LIBUSB_SPEED_SUPER): "SUPER",
+}
+
 type ControlSetup C.struct_libusb_control_setup
 type Transfer C.struct_libusb_transfer
 
@@ -43,6 +51,28 @@ const CLASS_WIRELESS = 0xe0
 const CLASS_APPLICATION = 0xfe
 const CLASS_VENDOR_SPEC = 0xff
 
+// Device and/or interface class codes.
+var CLASS_names = map[byte]string{
+	0: "PER_INTERFACE",
+	1: "AUDIO",
+	2: "COMM",
+	3: "HID",
+	5: "PHYSICAL",
+	7: "PRINTER",
+	6: "IMAGE",
+	8: "MASS_STORAGE",
+	9: "HUB",
+	10: "DATA",
+	0x0b: "SMART_CARD",
+	0x0d: "CONTENT_SECURITY",
+	0x0e: "VIDEO",
+	0x0f: "PERSONAL_HEALTHCARE",
+	0xdc: "DIAGNOSTIC_DEVICE",
+	0xe0: "WIRELESS",
+	0xfe: "APPLICATION",
+	0xff: "VENDOR_SPEC",
+}
+
 // Descriptor types as defined by the USB specification.
 const DT_DEVICE = 0x01
 const DT_CONFIG = 0x02
diff --git a/usb/usb_test.go b/usb/usb_test.go
new file mode 100644
index 0000000..6051223
--- /dev/null
+++ b/usb/usb_test.go
@@ -0,0 +1,72 @@
+package usb
+
+import (
+	"testing"
+)
+
+func TestDevice(t *testing.T) {
+	c := NewContext()
+	defer c.Exit()
+	l, err := c.GetDeviceList()
+	if err != nil {
+		t.Fatal("GetDeviceList failed:", err)
+	}
+
+	for _, dev := range l {
+		t.Logf("bus 0x%x addr 0x%x speed 0x%x\n",
+			dev.GetBusNumber(), dev.GetDeviceAddress(), dev.GetDeviceSpeed())
+		dd, err := dev.GetDeviceDescriptor()
+		if err != nil {
+			t.Logf("GetDeviceDescriptor failed: %v", err)
+			continue
+		}
+
+		t.Logf("Vendor/Product %x:%x Class/subclass/protocol %x:%x:%x: %s\n",
+			dd.IdVendor,  dd.IdProduct, dd.DeviceClass, dd.DeviceSubClass, dd.DeviceProtocol, CLASS_names[dd.DeviceClass])
+
+		stringDescs :=[]byte{
+			dd.Manufacturer, dd.Product, dd.SerialNumber,
+		}
+		
+		for i := 0; i < int(dd.NumConfigurations); i++ {
+			cd, err := dev.GetConfigDescriptor(byte(i))
+			if err != nil {
+				t.Logf("GetConfigDescriptor failed: %v", err)
+				continue
+			}
+			stringDescs = append(stringDescs, cd.ConfigurationIndex)
+			t.Logf(" config value %x, attributes %x power %d\n", cd.ConfigurationValue, 
+				cd.Attributes, cd.MaxPower)
+			for idx, iface := range cd.Interfaces {
+				t.Logf("  iface %d\n", idx)
+				for _, alt := range iface.AltSetting {
+					t.Logf("   num %d class/subclass/protocol %x/%x/%x\n",
+						alt.InterfaceNumber, alt.InterfaceClass, alt.InterfaceSubClass, alt.InterfaceProtocol)
+					for _, ep := range alt.EndPoints {
+						t.Logf("    %v", &ep)
+					}
+					stringDescs = append(stringDescs, alt.InterfaceStringIndex)
+				}
+			}
+		}
+
+		dh, err := dev.Open()
+		if err != nil {
+			t.Logf("can't open: %v", err)
+			continue
+		}
+
+		for _, c := range stringDescs {
+			str, err := dh.GetStringDescriptorASCII(c)
+			if err != nil {
+				t.Logf("GetStringDescriptorASCII %d failed: %v", c, err)
+				continue
+			}
+			t.Logf(" desc %d: %s", c, str)
+		}
+		dh.Close()
+	}
+}
+
+	
+