kmk_firmware/docs/encoder.md

# Encoder module
Add twist control to your keyboard! Volume, zoom, anything you want.

I2C encoder type has been tested with the Adafruit I2C QT Rotary Encoder with NeoPixel.

**Note:** If you have a **split** keyboard and encoders on **both sides** should work, it's currently necessary to use the encoder-scanner explained at the bottom of [scanners docs](scanners.md).

## Enabling the extension
The constructor(`EncoderHandler` class) takes a list of encoders, each one defined as either:

* a list of `pad_a` pin, `pad_b` pin, `button_pin` and optionally a flag set to `True` if you want encoder direction to be reversed;
* a `busio.I2C`, address and optionally a flag set to `True` if you want it to be reversed.

The `encoder_map` is modeled after the keymap and works the same way. It should have as many layers (key pressed on "turned left", key pressed on "turned right", key pressed on "knob pressed") as your keymap, and use `KC.NO` keys for layers that you don't require any action. The encoder supports a velocity mode if you desire to make something for video or sound editing. 



## How to use
Here is all you need to use this module in your `main.py` / `code.py` file.

1. Load the module.

```python
from kmk.modules.encoder import EncoderHandler
encoder_handler = EncoderHandler()
keyboard.modules = [layers, modtap, encoder_handler]
```

2. Define the pins for each encoder: `pin_a`, `pin_b` for rotations, `pin_button` for the switch in the encoder (set to `None` if the encoder's button is handled differently or not at all). If you want to invert the direction of the encoder, set the 4th (optional) parameter `is_inverted` to `True`. 5th parameter is [encoder resolution](#encoder-resolution), it can be either `2` or `4`.
 
```python
# Regular GPIO Encoder
encoder_handler.pins = ((board.GP17, board.GP15, board.GP14, False), (encoder 2 definition), etc. )
```

Or in case you have an I2C encoder on a special PCB (e.g. Adafruit I2C QT Rotary Encoder), define I2C encoder as following.

```python
# I2C Encoder

# Setup i2c
SDA = board.GP0
SCL = board.GP1
i2c = busio.I2C(SCL, SDA)

encoder_handler.pins = ((i2c, 0x36, False), (encoder 2 definition), etc. )
```

3. Define the mapping of keys to be called for each layer.

```python
# You can optionally predefine combo keys as for your layout
Zoom_in = KC.LCTRL(KC.EQUAL)
Zoom_out = KC.LCTRL(KC.MINUS)

encoder_handler.map = [(( KC.VOLD, KC.VOLU, KC.MUTE), (encoder 2 definition), etc. ), # Layer 1
                      ((Zoom_out, Zoom_in, KC.NO), (encoder 2 definition), etc. ), # Layer 2
                      ((KC.A, KC.Z, KC.N1), (encoder 2 definition), etc. ), # Layer 3
                      ((KC.NO, KC.NO, KC.NO), (encoder 2 definition), etc. ), # Layer 4
                      ]
```

## Encoder resolution

Depending on your encoder precision, it may send 4 or 2 pulses on every detent. By default the encoder resolution is set to 4, but if your an encoder only activates on every second detent (skips pulses), set the resolution to 2. If the encoder activates twice on every detent, set the value to 4.

You can change the default globally for all encoders **before** initializing the encoder pins (`main.py` file):
```python
encoder_handler.resolution = 2
encoder_handler.pins = ( (board.GP14, board.GP15, None), (board.GP26, board.GP27, None), )
```

Or if you have different types of encoders, set resolution for each encoder individually:
```python
encoder_handler.pins = (
    (board.GP14, board.GP15, None, False, 4), 
    (board.GP26, board.GP27, None, False, 2),
    (board.GP26, board.GP27, None ), # will be set to global default
)
```

This setting is equivalent to `divisor` in the [rotaryio](https://docs.circuitpython.org/en/latest/shared-bindings/rotaryio/index.html#rotaryio.IncrementalEncoder.divisor) module.
The resolution of `1` for smooth encoders is not currently supported but you can use the resolution of `2` for them without issues and any noticeable difference. 

## Handler methods overrides

Encoder methods `on_move_do` and `on_button_do` can be overridden for complex use cases.

---


## Full example (with 1 encoder)

```python
import board

from kmk.kmk_keyboard import KMKKeyboard
from kmk.consts import UnicodeMode
from kmk.keys import KC
from kmk.scanners import DiodeOrientation
from kmk.modules.layers import Layers
from kmk.modules.encoder import EncoderHandler


keyboard = KMKKeyboard()
layers = Layers()
encoder_handler = EncoderHandler()
keyboard.modules = [layers, encoder_handler]


keyboard.col_pins = (
    board.GP0, board.GP1, board.GP2, board.GP3, board.GP4, board.GP5,
    board.GP6, board.GP7, board.GP8, board.GP9, board.GP10, board.GP11,
    board.GP12, board.GP13,
)
keyboard.row_pins = (board.GP28, board.GP27, board.GP22, board.GP26, board.GP21)
keyboard.diode_orientation = DiodeOrientation.COLUMNS

# I2C example
#import busio
#SDA = board.GP0
#SCL = board.GP1
#i2c = busio.I2C(SCL, SDA)
#encoder_handler.i2c = ((i2c, 0x36, False),)

# encoder_handler.resolution = 2 # for encoders with more precision
encoder_handler.pins = ((board.GP17, board.GP15, board.GP14, False),)

keyboard.tap_time = 250
keyboard.debug_enabled = False


# Filler keys
_______ = KC.TRNS
xxxxxxx = KC.NO
tbdtbd = KC.A


# Layers
LYR_STD, LYR_EXT, LYR_NUM, LYR_GAME = 0, 1, 2, 3

TO_STD = KC.DF(LYR_STD)
MT_EXT = KC.MO(LYR_EXT)
TO_NUM = KC.MO(LYR_NUM)
TO_GAME = KC.DF(LYR_GAME)


# Keymap

keyboard.keymap = [
    # Standard (ISO) Layer
    [
        KC.ESC , KC.N1  , KC.N2  , KC.N3  , KC.N4  , KC.N5  , KC.N6  , KC.N7  , KC.N8  , KC.N9  , KC.N0  , KC.MINS, KC.EQL , KC.BSPC,
        KC.TAB , KC.Q   , KC.W   , KC.E   , KC.R   , KC.T   , KC.Y   , KC.U   , KC.I   , KC.O   , KC.P   , KC.LBRC, KC.RBRC, KC.DEL ,
        xxxxxxx, KC.A   , KC.S   , KC.D   , KC.F   , KC.G   , KC.H   , KC.J   , KC.K   , KC.L   , KC.SCLN, KC.QUOT, KC.NUHS, xxxxxxx,
        KC.LSFT, KC.NUBS, KC.Z   , KC.X   , KC.C   , KC.V   , KC.B   , KC.N   , KC.M   , KC.COMM, KC.DOT , KC.SLSH, KC.UP  , KC.ENT ,
        KC.LCTL, KC.LGUI, xxxxxxx, KC.LALT, MT_EXT , xxxxxxx, KC.SPC , xxxxxxx, KC.RALT, TO_NUM , KC.RSFT, KC.LEFT, KC.DOWN, KC.RGHT,
    ],
    # Extra Keys Layer
    [
        TO_STD , KC.F1  , KC.F2  , KC.F3  , KC.F4  , KC.F5  , KC.F6  , KC.F7  , KC.F8  , KC.F9  , KC.F10 , KC.F11 , KC.F12 , KC.RESET,
        _______, KC.N1  , KC.N2  , KC.N3  , KC.N4  , KC.N5  , KC.N6  , KC.N7  , KC.N8  , KC.N9  , KC.N0  , KC.MINS, KC.EQL , _______,
        xxxxxxx, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, xxxxxxx,
        KC.LSFT, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, KC.PGUP, _______,
        KC.LCTL, KC.LGUI, xxxxxxx, KC.LALT, MT_EXT , xxxxxxx, _______, xxxxxxx, _______, TO_NUM , _______, KC.HOME, KC.PGDN, KC.END ,
    ],
    # NumPad Layer
    [
        TO_STD , xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, KC.P7  , KC.P8  , KC.P9  , KC.PSLS, xxxxxxx, xxxxxxx, KC.BSPC,
        xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, KC.P4  , KC.P5  , KC.P6  , KC.PAST, xxxxxxx, xxxxxxx, KC.DEL ,
        xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, KC.LPRN, KC.P1  , KC.P2  , KC.P3  , KC.PPLS, xxxxxxx, xxxxxxx, xxxxxxx,
        xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, KC.RPRN, KC.P0  , KC.PDOT, _______, KC.PMNS, xxxxxxx, xxxxxxx, KC.PENT,
        xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, MT_EXT , xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, TO_NUM , xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx,
    ],
    # Gaming Layer
    [
        TO_STD , xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx,
        xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx,
        xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx,
        xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx,
        xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, MT_EXT , xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx, TO_NUM , xxxxxxx, xxxxxxx, xxxxxxx, xxxxxxx,
    ],
]

# Rotary Encoder (1 encoder / 1 definition per layer)
encoder_handler.map = [ ((KC.UP, KC.DOWN, KC.MUTE),), # Standard
                        ((KC.VOLD, KC.VOLU, KC.MUTE),), # Extra
                        ((KC.A, KC.Z, KC.N1),), # NumPad not yet properly configured
                        ((KC.A, KC.Z, KC.N1),), # Gaming not yet properly configured
                        ]

if __name__ == "__main__":
    keyboard.go()
```