1.**Toolchain** On Windows install [Atmel AVR Toolchain][atmelgcc] for AVR GCC compiler and [Cygwin][cygwin](or [MinGW][mingw]) for shell terminal. On Mac you can use [CrossPack][crosspack] or your favorite package manager. On Linux you can install AVR GCC with your favorite package manager.
3.**Driver** On Windows when you start DFU bootloader on the chip first time you will see **Found New Hardware Wizard** to install driver. If you install device driver properly you will find chip name like **ATmega32U4** under **LibUSB-Win32 Devices** tree on **Device Manager**. If not you shall need to update its driver on **Device Manager**. You will find the driver in `FLIP` install directory like: `C:\Program Files (x86)\Atmel\Flip 3.4.5\usb\`. In case of `dfu-programmer` install driver distributed with it.
cd tmk_keyboard/{'keyboard' or 'converter'}/<project>
### 3. Make
Build firmware using GNU `make` command. You'll see `<project>_<variant>.hex` file in that directory unless something unexpected occurs in build process.
make -f Makefile.<variant> clean
make -f Makefile.<variant>
Program Controller
------------------
Now you have **hex** file to program on current directory. This **hex** is only needed to program your controller, other files are used for development and you may leave and forget them.
### 1. Start bootloader
How to program controller depends on controller chip and its board design. To program AVR USB chips you'll need to start it up in bootloader mode. Most of boards with the chip have a push button to let bootloader come up. Consult with your controller board manual.
Stock AVR USB chips have DFU bootloader by factory default. `FLIP` is a DFU programmer on Windows offered by Atmel. `FLIP` has two version of tool, GUI app and command line program. If you want GUI see tutorial below. Open source alternative `dfu-programmer` also supports AVR chips, it is command line tool and runs on Linux, Mac OSX and even Windows.
`<controller>` part will be `atmega32u4` or `atmega32u2` in most cases. See manual of the command for the detail. On Linux and Mac OSX you will need proper permission to program a controller and you can use `sudo` command for this purpose probably. On Linux you also can configure `udev` rules to set permission.
1. On menu bar click **Device** -> **Select**, then choose your chip name. (In most cases **ATmega32U2** or **ATmega32U4**)
2. On menu bar click **Settings** -> **Communication** -> **USB**, then click **Open** button on **USB Port Connection** dialog. At this point you'll have to plug into USB and start bootloader.
3. On menu bar click **File** -> **Load HEX File**, then select your firmware hex file on File Selector dialog.
4. On **Operations Flow** panel click **Run** button to load the firmware binary to the chip. Note that you should keep **Erase**, **Blank Check**, **Program** and **Verify** check boxes selected.
5. Re-plug USB cord or click **Start Application** button to restart your controller.
If you are using PJRC Teensy consult with instruction of [Teensy Loader][teensy-loader]. Or run this target with `make` after you install command line version of it.
You may want to use other programmer like [`avrdude`][avrdude]. In that case you can still use make target `program` for build with configuring `PROGRAM_CMD` in Makefile. See below.
