You have found the QMK Firmware documentation site. This is a keyboard firmware based on the [tmk_keyboard firmware](http://github.com/tmk/tmk_keyboard) with some useful features for Atmel AVR controllers, and more specifically, the [OLKB product line](http://olkb.com), the [ErgoDox EZ](http://www.ergodox-ez.com) keyboard, and the [Clueboard product line](http://clueboard.co/). It has also been ported to ARM chips using ChibiOS. You can use it to power your own hand-wired or custom keyboard PCB.
Understanding the essential changes made on the [tmk_keyboard firmware](http://github.com/tmk/tmk_keyboard) should help you understand the QMK Firmware.
| `keymaps` array data | 3D array of `uint8_t` holding **keycode** | 3D array of `uint16_t` holding **keycode** |
| `fn_actions` array data | 1D array of `uint16_t` holding **action code** | 1D array of `uint16_t` holding **action code** |
You have found the QMK Firmware documentation site. This is a keyboard firmware based on the [tmk_keyboard firmware](http://github.com/tmk/tmk_keyboard) ([view differences](Differences-from-TMK)) with some useful features for Atmel AVR controllers, and more specifically, the [OLKB product line](http://olkb.com), the [ErgoDox EZ](http://www.ergodox-ez.com) keyboard, and the [Clueboard product line](http://clueboard.co/). It has also been ported to ARM chips using ChibiOS. You can use it to power your own hand-wired or custom keyboard PCB.
Jack Humbert
8 years ago