Here you go, an example that enumerates as a HID Pen device. It is test code and not cleaned up, maybe hard to read, but you’ll figure it out 
For your project you’ll just need to change the hidGenericReportDescriptorPayload I guess.
using System;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using GHIElectronics.NETMF.FEZ;
using GHIElectronics.NETMF.USBClient;
using GHIElectronics.NETMF.Hardware;
using MS = Microsoft.SPOT.Hardware.UsbClient;
using Microsoft.SPOT.Net.NetworkInformation;
using Microsoft.SPOT.Touch;
namespace USBClient_Example
{
public class Program
{
const int USBSTREAM_WRITE_ENDPOINT = 1;
const int USBSTREAM_READ_ENDPOINT = 2;
const int MAXPOWER_MILLIAMPS = 280; // default; can be up to 500mA
const int HID_DESCRIPTOR_TYPE = 0x21;
public static void Main()
{
NetworkInterface interf = NetworkInterface.GetAllNetworkInterfaces()[0];
interf.EnableStaticIP("192.168.1.200", "255.255.255.0", "192.168.1.1");
OutputPort LED;
LED = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.LED, true);
TouchPanel touch = Touch.ActiveTouchPanel;
touch.Enabled = true;
InputPort buttonUp = new InputPort((Cpu.Pin)FEZ_Pin.Digital.ButtonUp, true, Port.ResistorMode.PullUp);
InputPort buttonDown = new InputPort((Cpu.Pin)FEZ_Pin.Digital.ButtonDown, true, Port.ResistorMode.PullUp);
InputPort buttonSelect = new InputPort((Cpu.Pin)FEZ_Pin.Digital.ButtonSelect, true, Port.ResistorMode.PullUp);
// Check debug interface
if (Configuration.DebugInterface.GetCurrent() == Configuration.DebugInterface.Port.USB1)
{
Configuration.DebugInterface.Set(Configuration.DebugInterface.Port.Sockets1, Configuration.DebugInterface.Port.USB1);
throw new InvalidOperationException("Current debug interface is USB. Please restart your board.");
}
ushort myVID = 0x1234;
ushort myPID = 0x0007;
ushort myDeviceVersion = 0x100;
ushort myDeviceMaxPower = 250; // in milli amps
string companyName = "FastloadMedia";
string productName = "Pen device";
string myDeviceSerialNumber = "0";
// Create the device. Assume it just has one read and one write endpoints.
USBC_Device device = new USBC_Device(myVID, myPID, myDeviceVersion, myDeviceMaxPower, companyName, productName, myDeviceSerialNumber);
// Endpoints
byte writeEPNumber = device.ReserveNewEndpoint();
byte readEPNumber = device.ReserveNewEndpoint();
MS.Configuration.Endpoint[] epDesc = {
new MS.Configuration.Endpoint(writeEPNumber, MS.Configuration.Endpoint.ATTRIB_Write | MS.Configuration.Endpoint.ATTRIB_Interrupt),
new MS.Configuration.Endpoint(readEPNumber, MS.Configuration.Endpoint.ATTRIB_Read | MS.Configuration.Endpoint.ATTRIB_Interrupt),
};
epDesc[0].wMaxPacketSize = 16;
epDesc[0].bInterval = 10;
epDesc[1].wMaxPacketSize = 16;
epDesc[1].bInterval = 10;
// HID report descriptor
byte[] hidGenericReportDescriptorPayload = new byte[]
{
0x05, 0x0d, // USAGE_PAGE (Digitizers) 0
0x09, 0x02, // USAGE (Pen) 2
0xa1, 0x01, // COLLECTION (Application) 4
0x85, 0x01, // REPORT_ID (Pen) 6
0x09, 0x20, // USAGE (Stylus) 8
0xa1, 0x00, // COLLECTION (Physical) 10
0x09, 0x42, // USAGE (Tip Switch) 12
0x09, 0x44, // USAGE (Barrel Switch) 14
0x09, 0x45, // USAGE (Eraser Switch) 16
0x09, 0x3c, // USAGE (Invert) 18
0x09, 0x32, // USAGE (In Range) 20
0x15, 0x00, // LOGICAL_MINIMUM (0) 22
0x25, 0x01, // LOGICAL_MAXIMUM (1) 24
0x75, 0x01, // REPORT_SIZE (1) 26
0x95, 0x05, // REPORT_COUNT (5) 28
0x81, 0x02, // INPUT (Data,Var,Abs) 30
0x95, 0x0b, // REPORT_COUNT (11) 32
0x81, 0x03, // INPUT (Cnst,Var,Abs) 34
0x05, 0x01, // USAGE_PAGE (Generic Desktop) 36
0x26, 0xff, 0x7f, // LOGICAL_MAXIMUM (32767) 38
0x75, 0x10, // REPORT_SIZE (16) 41
0x95, 0x01, // REPORT_COUNT (1) 43
0xa4, // PUSH 45
0x55, 0x0d, // UNIT_EXPONENT (-3) 46
0x65, 0x33, // UNIT (Inch,EngLinear) 48
0x09, 0x30, // USAGE (X) 50
0x35, 0x00, // PHYSICAL_MINIMUM (0) 52
0x46, 0x00, 0x00, // PHYSICAL_MAXIMUM (0) 54
0x81, 0x02, // INPUT (Data,Var,Abs) 57
0x09, 0x31, // USAGE (Y) 59
0x46, 0x00, 0x00, // PHYSICAL_MAXIMUM (0) 61
0x81, 0x02, // INPUT (Data,Var,Abs) 64
0xb4, // POP 66
0x05, 0x0d, // USAGE_PAGE (Digitizers) 67
0x09, 0x30, // USAGE (Tip Pressure) 69
0x81, 0x02, // INPUT (Data,Var,Abs) 71
0x09, 0x3d, // USAGE (X Tilt) 73
0x09, 0x3e, // USAGE (Y Tilt) 75
0x16, 0x01, 0x80, // LOGICAL_MINIMUM (-32767) 77
0x95, 0x02, // REPORT_COUNT (2) 80
0x81, 0x02, // INPUT (Data,Var,Abs) 82/84
0xc0, // END_COLLECTION 0/1
0xc0, // END_COLLECTION 0/1
};
// Class Descriptor
byte[] hidClassDescriptorPayload = new byte[]
{
0x01, 0x01, // bcdHID (v1.01)
0x00, // bCountryCode
0x01, // bNumDescriptors
0x22, // bDescriptorType (report)
(byte)hidGenericReportDescriptorPayload.Length, 0x00 // wDescriptorLength (report descriptor size in bytes)
};
// HID class descriptor
MS.Configuration.ClassDescriptor hidClassDescriptor = new MS.Configuration.ClassDescriptor(HID_DESCRIPTOR_TYPE, hidClassDescriptorPayload);
// Interface
MS.Configuration.UsbInterface usbInterface = new MS.Configuration.UsbInterface(0, epDesc);
usbInterface.classDescriptors = new MS.Configuration.ClassDescriptor[] { hidClassDescriptor };
usbInterface.bInterfaceClass = 0x03; // HID
usbInterface.bInterfaceSubClass = 0x00;
usbInterface.bInterfaceProtocol = 0x00;
// Attach interface
byte interfaceIndex = device.AddInterface(usbInterface, "My interface name");
MS.Configuration.GenericDescriptor hidGenericReportDescriptor = new MS.Configuration.GenericDescriptor(0x81, 0x2200, hidGenericReportDescriptorPayload);
hidGenericReportDescriptor.bRequest = 0x06; // GET_DESCRIPTOR
hidGenericReportDescriptor.wIndex = 0x00; // INTERFACE 0 (zero)
// attach descriptor
device.AddDescriptor(hidGenericReportDescriptor);
// Strings
MS.Configuration.StringDescriptor stringDescriptor1 = new MS.Configuration.StringDescriptor(1, "String 1");
MS.Configuration.StringDescriptor stringDescriptor2 = new MS.Configuration.StringDescriptor(2, "String 2");
device.AddDescriptor(stringDescriptor1);
device.AddDescriptor(stringDescriptor2);
// This is used for reading and writing
USBC_Stream stream = device.CreateUSBStream(writeEPNumber, readEPNumber);
// All done, you can start the device now
USBClientController.Start(device);
byte[] report = new byte[13];
int x = 0;
int y = 0;
while (USBClientController.GetState() != USBClientController.State.Running)
{
Debug.Print("Waiting to connect to PC...");
Thread.Sleep(1000);
}
while (true)
{
Thread.Sleep(20);
// Check if connected to PC
if (!buttonUp.Read())
x += 32;
if (!buttonDown.Read())
y += 32;
report[0] = 0x01;
bool pressed = !buttonSelect.Read();
report[1] = (byte)(pressed ? 0x31 : 0x30);
report[3] = (byte)x;
report[4] = (byte)((x >> 8) & 0x7f);
report[5] = (byte)y;
report[6] = (byte)((y >> 8) & 0x7f);
report[7] = (byte)(pressed ? 0xFF : 0x00);
report[8] = 0x0;
stream.Write(report, 0, report.Length);
//report[9] = 0;
//report[10] = 0;
//report[11] = 0;
//report[12] = 0;
}
}
}
}
For your project you’ll just need to change the hidGenericReportDescriptorPayload I guess.