# Sequencer
Since QMK has experimental support for MIDI, you can now turn your keyboard into a [step sequencer](https://en.wikipedia.org/wiki/Music_sequencer#Step_sequencers)!
!> **IMPORTANT:** This feature is highly experimental, it has only been tested on a Planck EZ so far. Also, the scope will be limited to support the drum machine use-case to start with.
## Enable the step sequencer
Add the following line to your `rules.mk`:
```make
SEQUENCER_ENABLE = yes
```
By default the sequencer has 16 steps, but you can override this setting in your `config.h`:
```c
#define SEQUENCER_STEPS 32
```
## Tracks
You can program up to 8 independent tracks with the step sequencer. Select the tracks you want to edit, enable or disable some steps, and start the sequence!
## Resolutions
While the tempo defines the absolute speed at which the sequencer goes through the steps, the resolution defines the granularity of these steps (from coarser to finer).
|Resolution |Description |
|---------- |----------- |
|`SQ_RES_2` |Every other beat |
|`SQ_RES_2T` |Every 1.5 beats |
|`SQ_RES_4` |Every beat |
|`SQ_RES_4T` |Three times per 2 beats|
|`SQ_RES_8` |Twice per beat |
|`SQ_RES_8T` |Three times per beat |
|`SQ_RES_16` |Four times per beat |
|`SQ_RES_16T` |Six times per beat |
|`SQ_RES_32` |Eight times per beat |
## Keycodes
|Keycode |Description |
|------- |----------- |
|`SQ_ON` |Start the step sequencer |
|`SQ_OFF` |Stop the step sequencer |
|`SQ_TOG` |Toggle the step sequencer playback |
|`SQ_SALL`|Enable all the steps |
|`SQ_SCLR`|Disable all the steps |
|`SQ_S(n)`|Toggle the step `n` |
|`SQ_TMPD`|Decrease the tempo |
|`SQ_TMPU`|Increase the tempo |
|`SQ_R(n)`|Set the resolution to n |
|`SQ_RESD`|Change to the slower resolution |
|`SQ_RESU`|Change to the faster resolution |
|`SQ_T(n)`|Set `n` as the only active track or deactivate all |
## Functions
|Function |Description |
|-------- |----------- |
|`bool is_sequencer_on(void);` |Return whether the sequencer is playing |
|`void sequencer_toggle(void);` |Toggle the step sequencer playback |
|`void sequencer_on(void);` |Start the step sequencer |
|`void sequencer_off(void);` |Stop the step sequencer |
|`bool is_sequencer_step_on(uint8_t step);` |Return whether the step is currently enabled |
|`void sequencer_set_step(uint8_t step, bool value);` |Enable or disable the step |
|`void sequencer_set_step_on();` |Enable the step |
|`void sequencer_set_step_off();` |Disable the step |
|`void sequencer_toggle_step(uint8_t step);` |Toggle the step |
|`void sequencer_set_all_steps(bool value);` |Enable or disable all the steps |
|`void sequencer_set_all_steps_on();` |Enable all the steps |
|`void sequencer_set_all_steps_off();` |Disable all the steps |
|`uint8_t sequencer_get_tempo(void);` |Return the current tempo |
|`void sequencer_set_tempo(uint8_t tempo);` |Set the tempo to `tempo` (between 1 and 255) |
|`void sequencer_increase_tempo(void);` |Increase the tempo |
|`void sequencer_decrease_tempo(void);` |Decrease the tempo |
|`sequencer_resolution_t sequencer_get_resolution(void);` |Return the current resolution |
|`void sequencer_set_resolution(sequencer_resolution_t resolution);` |Set the resolution to `resolution` |
|`void sequencer_increase_resolution(void);` |Change to the faster resolution |
|`void sequencer_decrease_resolution(void);` |Change to the slower resolution |
|`bool is_sequencer_track_active(uint8_t track);` |Return whether the track is active |
|`void sequencer_set_track_activation(uint8_t track, bool value);` |Activate or deactivate the `track` |
|`void sequencer_toggle_track_activation(uint8_t track);` |Toggle the `track` |
|`void sequencer_activate_track(uint8_t track);` |Activate the `track` |
|`void sequencer_deactivate_track(uint8_t track);` |Deactivate the `track` |
|`void sequencer_toggle_single_active_track(uint8_t track);` |Set `track` as the only active track or deactivate all |