On macOS, install the Arduino IDE using homebrew cask with brew cask install arduino or download the application from the official website and move it to your /Applications folder.

Linux

On Linux, your distribution's package manager probably includes the Arduino IDE, but it may be an out of date version. If your distribution installs a version of Arduino before 1.6.3 or so, you'll need to install the Arduino IDE following the instructions on the wiki.

If you install Arduino into some place that's /not/ /usr/local/arduino, you'll need to set the $ARDUINO_PATH environment variable to the directory containing the arduino and arduino-builder binaries.

Create and navigate to the Arduino Sketchbook directory

MacOS

mkdir -p $HOME/Documents/Arduino
cd $HOME/Documents/Arduino

Linux

mkdir -p $HOME/Arduino
cd $HOME/Arduino

Download hardware platform, including library source code

mkdir -p hardware/keyboardio

## then clone the hardware definitions to make them available to the arduino environment
git clone --recursive https://github.com/keyboardio/Arduino-Boards.git hardware/keyboardio/avr

Download the Model 01 Firmware

git clone https://github.com/keyboardio/Model01-Firmware.git

Build and flash the firmware

Before you begin, make sure your Model 01 is connected to your computer.

Option 1: From the command line

cd Model01-Firmware
make flash

When the builder tells you to hit Enter to continue, hold down "Prog" in the top left corner of your keyboard and hit Enter.

Option 2: From the Arduino IDE

Open the sketch you wish to flash (for example, Model01-Firmware.ino).

Click the Upload button or press Ctrl-U.

Hold down the "Prog" key in the top left corner of your keyboard, until the compile finishes and the upload begins.

Thanks!

<3 jesse