LUFA/ManPages/GettingStarted.txt

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   7 /** \page Page_GettingStarted Getting Started
   8  *
   9  *  Out of the box, LUFA contains a large number of pre-made class demos for you to test, experiment with and
  10  *  ultimately build upon for your own projects. All the demos come pre-configured to build and run correctly
  11  *  on the AT90USB1287 AVR microcontroller, mounted on the Atmel USBKEY board and running at an 8MHz master clock.
  12  *  This is due to two reasons; one, it is the hardware the author possesses, and two, it is the most popular Atmel
  13  *  USB demonstration board to date.
  14  *
  15  *
  16  *  \section Sec_Prerequisites Prerequisites
  17  *  Before you can compile any of the LUFA library code or demos, you will need a recent distribution of avr-libc (1.6.2+)
  18  *  and the AVR-GCC (4.2+) compiler. For Windows users, the best way to obtain these is the WinAVR project
  19  *  (http://winavr.sourceforge.net) as this provides a single-file setup for everything required to compile your
  20  *  own AVR projects.
  21  *
  22  *
  23  *  \section Sec_Configuring Configuring the Demos, Bootloaders and Projects
  24  *  If the target AVR model, clock speed, board or other settings are different to the current settings, they must be changed
  25  *  and the project recompiled from the source code before being programmed into the AVR microcontroller. Most project
  26  *  configuration options are located in the "makefile" build script inside each LUFA application's folder, however some
  27  *  demo or application-specific configuration settings (such as the output format in the AudioOut demo) are located in the
  28  *  main .c source file of the project. See each project's individual documentation for application-specific configuration
  29  *  values.
  30  *
  31  *  Each project "makefile" contains all the script and configuration data required to compile each project. When opened with
  32  *  any regular basic text editor such as Notepad or WordPad (ensure that the save format is a pure ASCII text format) the
  33  *  build configuration settings may be altered.
  34  *
  35  *  Inside each makefile, a number of configuration variables are located, with the format "<VARIABLE NAME> = <VALUE>". For
  36  *  each application, the important variables which should be altered are:
  37  *
  38  *    - <b>MCU</b>, the target AVR processor.
  39  *    - <b>BOARD</b>, the target board hardware
  40  *    - <b>F_CLOCK</b>, the target raw master clock frequency, before any prescaling is performed
  41  *    - <b>F_CPU</b>, the target AVR CPU master clock frequency, after any prescaling
  42  *    - <b>CDEFS</b>, the C preprocessor defines which configure the source code
  43  *
  44  *  These values should be changed to reflect the build hardware.
  45  *
  46  *  \subsection SSec_MCU The MCU Parameter
  47  *  This parameter indicates the target AVR model for the compiled application. This should be set to the model of the target AVR
  48  *  (such as the AT90USB1287, or the ATMEGA32U4), in all lower-case (e.g. "at90usb1287"). Note that not all demos support all the
  49  *  USB AVR models, as they may make use of peripherals or modes only present in some devices.
  50  *
  51  *  For supported library AVR models, see main documentation page.
  52  *
  53  *  \subsection SSec_BOARD The BOARD Parameter
  54  *  This parameter indicates the target AVR board hardware for the compiled application. Some LUFA library drivers are board-specific,
  55  *  such as the LED driver, and the library needs to know the layout of the target board. If you are using one of the board models listed
  56  *  on the main library page, change this parameter to the board name in all UPPER-case.
  57  *
  58  *  If you are not using any board-specific drivers in the LUFA library, or you are using a custom board layout, change this to read
  59  *  "USER" (no quotes) instead of a standard board name. If the USER board type is selected and the application makes use of one or more
  60  *  board-specific hardware drivers inside the LUFA library, then the appropriate stub drives files should be copied from the /BoardStubs/
  61  *  directory into a /Board/ folder inside the application directory, and the stub driver completed with the appropriate code to drive the
  62  *  custom board's hardware.
  63  *
  64  *  \subsection SSec_F_CLOCK The F_CLOCK Parameter
  65  *  This parameter indicates the target AVR's input clock frequency, in Hz. This is the actual clock input, before any prescaling is performed. In the
  66  *  USB AVR architecture, the input clock before any prescaling is fed directly to the PLL subsystem, and thus the PLL is derived directly from the
  67  *  clock input. The PLL then feeds the USB and other sections of the AVR with the correct upscaled frequencies required for those sections to function.
  68  *
  69  *  <b>Note that this value does not actually *alter* the AVR's input clock frequency</b>, it is just a way to indicate to the library the clock frequency
  70  *  of the AVR as set by the AVR's fuses. If this value does not reflect the actual running frequency of the AVR, incorrect operation of one of more
  71  *  library components will occur.
  72  *
  73  *  \subsection SSec_F_CPU The F_CPU Parameter
  74  *  This parameter indicates the target AVR's master CPU clock frequency, in Hz.
  75  *
  76  *  <b>Note that this value does not actually *alter* the AVR's CPU clock frequency</b>, it is just a way to indicate to the library the clock frequency
  77  *  of the AVR core as set by the AVR's fuses. If this value does not reflect the actual running frequency of the AVR, incorrect operation of one of more
  78  *  library components will occur.
  79  *
  80  *  \subsection SSec_CDEFS The CDEFS Parameter
  81  *  Most applications will actually have multiple CDEF lines, which are concatenated together with the "+=" operator. This ensures that large
  82  *  numbers of configuration options remain readable by splitting up groups of options into separate lines.
  83  *
  84  *  Normally, these options do not need to be altered to allow an application to compile and run correctly on a different board or AVR to the
  85  *  current configuration - if the options are incorrect, then the demo is most likely incompatible with the chosen USB AVR model and cannot be
  86  *  made to function through the altering of the makefile settings alone (or at all). Settings such as the USB mode (device, host or both), the USB
  87  *  interface speed (Low or Full speed) and other LUFA configuration options can be set here - refer to the library documentation for details on the
  88  *  configuration parameters.
  89  *
  90  *
  91  *  \section Sec_Compiling Compiling a LUFA Application
  92  *  Compiling the LUFA demos, applications and/or bootloaders is very simple. LUFA comes with makefile scripts for
  93  *  each individual demo, bootloader and project folder, as well as scripts in the /Demos/, /Bootloaders/, /Projects/
  94  *  and the LUFA root directory. This means that compilation can be started from any of the above directories, with
  95  *  a build started from an upper directory in the directory structure executing build of all child directories under it.
  96  *  This means that while a build inside a particular demo directory will build only that particular demo, a build stated
  97  *  from the /Demos/ directory will build all LUFA demo projects sequentially.
  98  *
  99  *  \subsection SSec_CommandLine Via the Command Line
 100  *  To build a project from the source via the command line, the command <b>"make all"</b> should be executed from the command line in the directory
 101  *  of interest. To remove compiled files (including the binary output, all intermediately files and all diagnostic output
 102  *  files), execute <b>"make clean"</b>. Once a "make all" has been run and no errors were encountered, the resulting binary will
 103  *  be located in the generated ".HEX" file. If your project makes use of pre-initialized EEPROM variables, the generated ".EEP"
 104  *  file will contain the project's EEPROM data.
 105  *
 106  *  \subsection SSec_AVRStudio Via AVRStudio
 107  *  Each demo, project and bootloader contains an AVRStudio project (.aps) which can be used to build each project. Once opened
 108  *  in AVRStudio, the project can be built and cleaned using the GUI buttons or menus. Note that the AVRStudio project files make
 109  *  use of the external project makefile, thus the procedure for configuring a demo remains the same regardless of the build environment.
 110  *
 111  *
 112  *  \section Sec_Programming Programming a USB AVR
 113  *  Once you have built an application, you will need a way to program in the resulting ".HEX" file (and, if your
 114  *  application uses EEPROM variables with initial values, also a ".EEP" file) into your USB AVR. Normally, the
 115  *  reprogramming an AVR device must be performed using a special piece of programming hardware, through one of the
 116  *  supported AVR programming protocols - ISP, HVSP, HVPP, JTAG or dW. This can be done through a custom programmer,
 117  *  a third party programmer, or an official Atmel AVR tool - for more information, see the Atmel.com website.
 118  *
 119  *  Alternatively, you can use the bootloader. From the Atmel factory, each USB AVR comes preloaded with the Atmel
 120  *  DFU (Device Firmware Update) class bootloader, a small piece of AVR firmware which allows the remainder of the
 121  *  AVR to be programmed through a non-standard interface such as the serial USART port, SPI, or (in this case) USB.
 122  *  Bootloaders have the advantage of not requiring any special hardware for programming, and cannot usually be erased
 123  *  or broken without an external programming device. They have disadvantages however; they cannot change the fuses of
 124  *  the AVR (special configuration settings that control the operation of the chip itself) and a small portion of the
 125  *  AVR's FLASH program memory must be reserved to contain the bootloader firmware, and thus cannot be used by the
 126  *  loaded application. Atmel's DFU bootloader is either 4KB (for the smaller USB AVRs) or 8KB (for the larger USB AVRs).
 127  *
 128  *  If you wish to use the DFU bootloader to program in your application, refer to your DFU programmer's documentation.
 129  *  Atmel provides a free utility called FLIP which is USB AVR compatible, and an open source (Linux compatible)
 130  *  alternative exists called "dfu-programmer".
 131  */