126 lines
4.4 KiB
Markdown
126 lines
4.4 KiB
Markdown
Tutorial 3a - multi-layer keyboard
|
|
==================================
|
|
When you finish this tutorial you will be able to be able to modify a multi-layer keybrd sketch to suite your own multi-layer keyboard design.
|
|
|
|
## Multi-layer nomenclature
|
|
**[layers](http://deskthority.net/wiki/Layer)** are key bindings provided by the keyboard firmware. For example,
|
|
* The classic [IBM PC keyboard](http://en.wikipedia.org/wiki/IBM_PC_keyboard) has one layer.
|
|
* Many compact keyboards have an additional [Fn layer](http://en.wikipedia.org/wiki/Fn_key).
|
|
* The [Neo layout](http://neo-layout.org/index_en.html) has 6 layers.
|
|
|
|
**layer id** - is an integer used to identify a layer.
|
|
|
|
**active layer** - is the layer currently used by the keyboard.
|
|
|
|
**layer scheme** - is a system for changing layers while typing (a single-layer scheme does not change layers).
|
|
|
|
## Pseudo code for simple layer scheme
|
|
The following pseudo code has just enough detail to show how layer schemes work.
|
|
|
|
**Key_Layer** objects select the active layer.
|
|
The "layer" variable is a layer id number.
|
|
When a Key_Layer object is pressed, it tells LayerState to update the active layer.
|
|
```
|
|
class Key_Layer
|
|
{
|
|
int layer
|
|
LayerState& refLayerState
|
|
press() { refLayerState.setActiveLayer(layer) }
|
|
}
|
|
```
|
|
|
|
**LayerState** objects keep track of the active layer.
|
|
A LayerState's activeLayer is always up to date.
|
|
```
|
|
class LayerState
|
|
{
|
|
int activeLayer
|
|
setActiveLayer(int layer) { activeLayer = layer }
|
|
getActiveLayer() { return activeLayer }
|
|
}
|
|
```
|
|
|
|
**Key_Layered** objects contain multiple Key pointers, one Key pointer for each layer.
|
|
Layer ids are used like indexes to select the appropriate key.
|
|
When a Key_Layered object is pressed, it gets the active layer from LayerState, and then sends the key of the active layer.
|
|
```
|
|
class Key_Layered
|
|
{
|
|
Key** ptrsKeys //array of Key pointers, one Key pointer per layer
|
|
LayerState& refLayerState
|
|
press() { layer = refLayerState.getActiveLayer()
|
|
ptrsKeys[layer]->press() }
|
|
}
|
|
```
|
|
|
|
Dependency diagram
|
|
```
|
|
+-----------+
|
|
| Key_Layer |
|
|
+-----------+
|
|
|
|
|
|setActiveLayer()
|
|
|
|
|
v
|
|
+------------+
|
|
| LayerState |
|
|
+------------+
|
|
^
|
|
|
|
|
|getActiveLayer()
|
|
|
|
|
+-------------+
|
|
| Key_Layered |
|
|
+-------------+
|
|
```
|
|
## Layer-scheme classes
|
|
There are several layer scheme-classes to choose from.
|
|
You can view all the class definitions in the [keybrd library](../src/).
|
|
|
|
Key_Layer classes include:
|
|
* Code_LayerHold
|
|
* Code_LayerLock
|
|
|
|
A basic LayerState class is:
|
|
* LayerState
|
|
|
|
Key_Layered classes include:
|
|
* Code_LayeredScSc
|
|
* Code_LayeredCodeSc
|
|
* Code_LayeredCodeCode
|
|
* Key_LayeredKeysArray
|
|
|
|
## Single-layer Codes
|
|
Most Code objects only have one scancode or code.
|
|
They are not affected by the active layer.
|
|
Example single-layer Code classes include:
|
|
* Code_Sc
|
|
* Code_ScS
|
|
* Code_ScNS
|
|
* Code_Shift
|
|
* Code_LayerHold
|
|
* Code_LayerLock
|
|
|
|
<!-- todo -->
|
|
|
|
(Future version of keybrd library may change all Code classes to Key classes.)
|
|
|
|
## A simple multi-layer keybrd sketch
|
|
The [keybrd_3a_multi-layer_annotated.ino](keybrd_3a_multi-layer_annotated/keybrd_3a_multi-layer_annotated.ino)
|
|
sketch uses three layer-scheme classes:
|
|
* LayerState
|
|
* Code_LayerHold
|
|
* Key_LayeredKeysArray
|
|
|
|
Annotations in the sketch explain how the multi-layer feature works.
|
|
|
|
## Exercises
|
|
1) Modify the keybrd_3_multi-layer_annotated.ino sketch to use two Code_LayerLock objects.
|
|
|
|
| Layout | **0** | **1** |
|
|
|:------:|--------|--------|
|
|
| **0** | a 1 | b 2 |
|
|
| **1** | layer0 | layer1 |
|
|
|
|
<a rel="license" href="http://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by/4.0/88x31.png" /></a><br /><span xmlns:dct="http://purl.org/dc/terms/" property="dct:title">keybrd tutorial</span> by <a xmlns:cc="http://creativecommons.org/ns#" href="https://github.com/wolfv6/keybrd" property="cc:attributionName" rel="cc:attributionURL">Wolfram Volpi</a> is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>.<br />Permissions beyond the scope of this license may be available at <a xmlns:cc="http://creativecommons.org/ns#" href="https://github.com/wolfv6/keybrd/issues/new" rel="cc:morePermissions">https://github.com/wolfv6/keybrd/issues/new</a>.
|