I am having trouble getting a thumb drive recognized under 4.2 with a Spider mainboard.
The 4.2 SDK was already loaded on board.
I created a 4.2 Gadgeteer application which had a button, USB Host and T35 display. I added event
handlers for the button, and USB drive connect and disconnect.
The test program deploys normally. When the thumb drive is inserted into the host module, I
get the following exception:
#### Exception System.Exception - 0xffffffff (4) ####
#### Message:
#### GHI.Premium.IO.PersistentStorage::MountFileSystem [IP: 0000] ####
#### Gadgeteer.Modules.GHIElectronics.UsbHost::USBHostController_DeviceConnectedEvent [IP: 0026] ####
#### GHI.Premium.USBHost.USBH_DeviceConnectionEventHandler::Invoke [IP: 0000] ####
#### GHI.Premium.USBHost.USBHostController::nativeEventDispatcher_OnInterrupt [IP: 0037] ####
#### GHI.Premium.System.InternalEvent::nativeEventDispatcher_OnInterrupt [IP: 0054] ####
A first chance exception of type ‘System.Exception’ occurred in GHI.Premium.IO.dll
UsbHost ERROR : Unable to identify USB Host device.
The line “UsbHost ERROR : Unable to identify USB Host device.” is misleading. I checked the USB Host module
source, and the device was recognized. The driver code is organized in a way that this error message is
displayed if the device is recognized but an exception occurs. Might be worth while to add a return in the
exception handler to avoid the identify error message.
Back to the problem at hand…
Based upon the exception, which says there is a problem mounting the file system for the thumb drive,
I tried several other thumb drives. The exception continued. I reformatted the drive(fat32) but that
did not stop the exception.
I then decided to go back to the 4.1 SDK and see if the problem could be reproduced.
I did a firmware upgrade/downgrade from 4.2 to 4.1.
I then built a new 4.1 Gadgeteer solution/project which the same hardware configuration as
the 4.2 project. I then copied the 4.2 program.cs contents from the 4.2 project to
the 4.1 project, changing only the namespace name.
I compiled and deployed the 4.1 project, and inserted the thumb drive. It worked.
Mumble mumble… 
I then went back to 4.2 solution, after upgrading the firmware. and tried again. I got the
same exception.
program.generated.cs
//------------------------------------------------------------------------------
// <auto-generated>
// This code was generated by the Gadgeteer Designer.
//
// Changes to this file may cause incorrect behavior and will be lost if
// the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------
using Gadgeteer;
using GTM = Gadgeteer.Modules;
namespace Gadgeteer42_SSD
{
public partial class Program : Gadgeteer.Program
{
// GTM.Module definitions
Gadgeteer.Modules.GHIElectronics.UsbClientDP usbClientDP;
Gadgeteer.Modules.GHIElectronics.Display_T35 display_T35;
Gadgeteer.Modules.GHIElectronics.UsbHost usbHost;
Gadgeteer.Modules.GHIElectronics.Button button;
public static void Main()
{
//Important to initialize the Mainboard first
Mainboard = new GHIElectronics.Gadgeteer.FEZSpider();
Program program = new Program();
program.InitializeModules();
program.ProgramStarted();
program.Run(); // Starts Dispatcher
}
private void InitializeModules()
{
// Initialize GTM.Modules and event handlers here.
usbClientDP = new GTM.GHIElectronics.UsbClientDP(1);
usbHost = new GTM.GHIElectronics.UsbHost(3);
button = new GTM.GHIElectronics.Button(4);
display_T35 = new GTM.GHIElectronics.Display_T35(14, 13, 12, 10);
}
}
}
program.cs
using System;
using System.Collections;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Presentation;
using Microsoft.SPOT.Presentation.Controls;
using Microsoft.SPOT.Presentation.Media;
using Microsoft.SPOT.Touch;
using Gadgeteer.Networking;
using GT = Gadgeteer;
using GTM = Gadgeteer.Modules;
using Gadgeteer.Modules.GHIElectronics;
namespace Gadgeteer42_SSD
{
public partial class Program
{
private GT.StorageDevice storageDevice = null;
// private String fileName = "test.txt";
// This method is run when the mainboard is powered up or reset.
void ProgramStarted()
{
usbHost.USBDriveConnected += new UsbHost.USBDriveConnectedEventHandler(usbHost_USBDriveConnected);
usbHost.USBDriveDisconnected += new UsbHost.USBDriveDisconnectedEventHandler(usbHost_USBDriveDisconnected);
button.ButtonPressed += new Button.ButtonEventHandler(button_ButtonPressed);
}
void usbHost_USBDriveDisconnected(UsbHost sender)
{
Debug.Print("Drive disconnected");
}
void usbHost_USBDriveConnected(UsbHost sender, GT.StorageDevice storageDevice)
{
Debug.Print("Drive connected");
this.storageDevice = storageDevice;
}
void button_ButtonPressed(Button sender, Button.ButtonState state)
{
if (storageDevice == null)
return;
Debug.Print("Root Directory: " + storageDevice.RootDirectory);
String[] ts = storageDevice.ListRootDirectoryFiles();
String indent = new string(' ', 5);
Debug.Print("Directories:");
foreach (String s in ts)
Debug.Print(indent + s);
ts = storageDevice.ListRootDirectoryFiles();
foreach (String s in ts)
Debug.Print(indent + s);
}
}
}
Have I missed something that has changed between 4.1 and 4.2?
