Getting Started: Running the “Device - HID

1) If using the PICDEM FS USB Demo Board, no hardware related configuration or jumper setting changes should be necessary. The demo board need only be programmed with appropriate firmware.

Configuration 2: PIC18F87J50 PIM

1) Short JP4 on the PIC18F87J50 PIM. This allows the demo board to be powered through bus power.

2) Short JP1 such that the “R” and “U” options are shorted.

3) Short JP5. This enables the small surface mount LEDs D3 and D4 to function.

Configuration 3: Explorer 16

1) Before attaching the PIC24FJ256GB110 PIM to the Explorer 16 board, insure that the processor selector switch (S2) is in the “PIM” position as seen in the image below.

2) Short the J7 jumper to the “PIC24” setting

3) Before connecting the PIC24FJ256GB110 PIM to the Explorer 16 board, remove all attached cables from both boards. Connect the PIC24FJ256GB110 PIM to the Explorer 16 board. Be careful when connecting the boards to insure that no pins are bent or damaged during the process. Also insure that the PIM is not shifted in any direction and that all of the headers are properly aligned.

3a) If using the PIC24FJ64GB004 PIM, please insure that the programming port switch is switched in the PGX1 direction.

4) On the USB PICTail Plus board, short jumper JP1. Remove all other shorts on the board.

5) Connect the USB PICTail Plus board to either of the female PICTail Plus connectors or on the card edge connector (J9) at the edge of the Explorer 16 board.

Note: When using the HID bootloader for PIC32, it is important to modify the procdefs.ld file to relocate the sections of code that will hold the bootloader and those sections that will hold the user application. Example modified procdefs.ld files have been provided with each project. This file is currently named “Procdefs.ld.boot”. When using the example project with the bootloader it is required to remove the “.boot” section of the file. This will allow MPLAB to use this file instead of the default linker file. Once the linker file is renamed, however, the project will no longer work without the bootloader. Please rename the file in order to get the project working again with PIC32.

Configuration 4: Low Pin Count USB Development Kit

1) Short pins 2 and 3 of J14. Make sure J12 is left open.

Configuration 5: PIC24F Starter Kit 1

The PIC24F Starter Kit does not require any hardware setup to run this demo. This demo does, however, require the user to change the default selected device in the project before compiling the demo.

1) Open the associated project file for C30

2) In MPLAB Select “Configure->Select Device”

3) In the device list box in the top left corner of that window, select “PIC24FJ256GB106”

Configuration 6: PIC18F46J50 Full Speed USB Demo Board

1) Short JP3 to allow the board to be powered from the USB.

Configuration 7: PIC32 USB Starter Board

No specific hardware configuration is required for this demo. Connect the USB cable provided with the starter kit to the OTG connector J5 on the bottom side of the board.

Configuration 8: PIC18F Starter Kit

No specific hardware configuration is required for this demo.

Firmware:

To run this project, you will need to load the corresponding firmware into the microcontroller. Precompiled Demos are available in the “<Install Directory>\USB Precompiled Demos” folders. Each demo hex filename should include information regarding the hardware platform it is compiled for. For this demo, select the appropriate “HID - Simple Custom Demo” hex files that matches the hardware configuration that you plan to use.

For more information about how to load a precompiled project, please see the “Getting Started – Loading a precompiled demo” guide.

The source code for this demo firmware is available in the “<Install Directory\USB Device - HID - Simple Custom Demo\Generic HID - Firmware” directory. In this directory you will find all of the user level source and header files as well as project and workspace files for each of the hardware platforms.

For more help on how to compile and program projects, please refer to the MPLAB® IDE help available through the help menu of MPLAB (Help->Topics…->MPLAB IDE).

Please note that when using either the C30 or C32 demo projects you will be required to select the correct processor for the demo board.

1) Open the associated project file

2) In MPLAB Select “Configure->Select Device”

3) In the device list box in the top left corner of that window, select the desired device.

Running the Demo:

This demo uses the selected hardware platform as a HID class USB device, but uses the HID class for general purpose I/O operations. Typically, the HID class is used to implement human interface products, such as mice and keyboards. The HID protocol is however quite flexible, and can be adapted and used to send/receive general purpose data to/from a USB device. Using the HID class for general purpose I/O operations is quite advantageous, in that it does not require any kind of custom driver installation process. HID class drivers are already provided by and are distributed with common operating systems. Therefore, upon plugging in a HID class device into a typical computer system, no user installation of drivers is required, the installation is fully automatic.

HID devices primarily communicate through one interrupt IN endpoint and one interrupt OUT endpoint. In most applications, this effectively limits the maximum achievable bandwidth for full speed HID devices to 64kBytes/s of IN traffic, and 64kBytes/s of OUT traffic (64kB/s, but effectively “full duplex”).

The GenericHIDSimpleDemo.exe program, and the associated firmware demonstrate how to use the HID protocol for basic general purpose USB data transfer. To make the PC source code as easy to understand as possible, the demo has deliberately been made simple, and only sends/receives small amounts of data.

Before you can run the GenericHIDSimpleDemo.exe executable, you will need to have the Microsoft® .NET Framework Version 2.0 Redistributable Package (later versions probably okay, but not tested) installed on your computer. Programs which were built in the Visual Studio® .NET languages require the .NET redistributable package in order to run. The redistributable package can be freely downloaded from Microsoft’s website. Users of Windows Vista® operating systems will not need to install the .NET framework, as it comes pre-installed as part of the operating system.

The source code for GenericHIDSimpleDemo.exe file was created in Microsoft Visual C++® 2005 Express Edition. The source code can be found in the “<Install Directory>\ USB Device - HID - Custom Demos\Generic HID - Simple Demo - PC Software” directory. Microsoft currently distributes Visual C++ 2005 Express Edition for free, and can be downloaded from Microsoft’s website. When downloading Microsoft Visual C++ 2005 Express Edition, also make sure to download and install the Platform SDK, and follow Microsoft’s instructions for integrating it with the development environment.

It is not necessary to install either Microsoft Visual C++ 2005, or the Platform SDK in order to begin using the GenericHIDSimpleDemo.exe program. These are only required if the source code will be modified or compiled.

To launch the application, simply double click on the executable “GenericHIDSimpleDemo.exe” in the “<Install Directory>\USB Device - HID - Custom Demos” directory. A window like that shown below should appear:

If instead of this window, an error message pops up while trying to launch the application, it is likely the Microsoft .NET Framework Version 2.0 Redistributable Package has not yet been installed. Please install it and try again.

In order to begin sending/receiving packets to the device, you must first find and “connect” to the device. As configured by default, the application is looking for HID class USB devices with VID = 0x04D8 and PID = 0x003F. The device descriptor in the firmware project meant to be used with this demo uses the same VID/PID. If you plug in a USB device programmed with the correct precompiled .hex file, and hit the “Connect” button, the other pushbuttons should become enabled. If hitting the connect button has no effect, it is likely the USB device is either not connected, or has not been programmed with the correct firmware.

Hitting the Toggle LED(s) should send a single packet of general purpose generic data to the HID class USB peripheral device. The data will arrive on the interrupt OUT endpoint. The firmware has been configured to receive this generic data packet, parse the packet looking for the “Toggle LED(s)” command, and should respond appropriately by controlling the LED(s) on the demo board.

The “Get Pushbutton State” button will send one packet of data over the USB to the peripheral device (to the interrupt OUT endpoint) requesting the current pushbutton state. The firmware will process the received Get Pushbutton State command, and will prepare an appropriate response packet depending upon the pushbutton state.

For hardware configuration 1 (PICDEM FS USB Demo Board), the firmware will check pushbutton “S2” (RB4).

For hardware configuration 2 (PIC18F87J50 PIM), the firmware will check pushbutton “S4” (RB4).

For hardware configuration 3 (Explorer 16), the firmware will check pushbutton “S6” (RD7).

For hardware configuration 4 (Low Pin Count USB Development Kit), the firmware will check pushbutton “S1” (RA3).

For hardware configuration 5 (PIC24F Starter Kit 1), the pushbutton functionality is not currently implement. This functionality is not present in this demo.

For hardware configuration 6 (PIC18F46J50 Full Speed USB Demo Board), the firmware will check pushbutton “S2” (RB2).

For hardware configuration 7 (PIC32 USB Starter Kit), the firmware will check pushbutton “SW2” (RD7).

For hardware configuration 8 (PIC18F Starter Kit), there are no LEDs available, therefore the “Toggle LED(s)” command will not do anything. The firmware will check the “Menu” pushbutton located near the MicroSD connector.

The PC then requests a packet of data from the device (which will be taken from the interrupt IN endpoint). Once the PC application receives the response packet, it will update the pushbutton state label.

Try experimenting with the application by holding down the appropriate pushbutton on the demo board, and then simultaneously clicking on the “Get Pushbutton State” button. Then try to repeat the process, but this time without holding down the pushbutton on the demo board.

To make for a more fluid and gratifying end user experience, a real USB application would probably want to launch a separate thread to periodically poll the pushbutton state, so as to get updates regularly. This is not done in this simple demo, so as to avoid cluttering the PC application project with source code that is not related to USB communication.

Trademarks:

The Microchip name and logo, the Microchip logo, MPLAB, and PIC are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.

PICDEM and PICTail are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.

Microsoft, Windows, Visual Studio, Visual C++, and Windows Vista are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries.