46 lines
3.0 KiB
Markdown
46 lines
3.0 KiB
Markdown
|
keybrd Tutorial 7ab - mapping layout to matrix
|
||
|
|
============================================
|
||
|
|
After reading this tutorial you will be able to map a keyboard layout to a keyboard matrix.
|
||
|
|
|
||
|
|
Keyboard mapping nomenclature
|
||
|
|
-----------------------------
|
||
|
|
**[Keyboard layout](http://en.wikipedia.org/wiki/Keyboard_layout)** - is the placement of keys. Key caps are often labeled to show a keyboard's layout.
|
||
|
|
|
||
|
|
**[Matrix](http://pcbheaven.com/wikipages/How_Key_Matrices_Works/)** - is a collection of switches electrically connected into rows and columns.
|
||
|
|
|
||
|
|
**[Transpose](https://en.wikipedia.org/wiki/Transpose)** - is the mapping of layout rows to matrix columns. Used when diodes are oriented with anodes towards the matrix rows.
|
||
|
|
|
||
|
|
When to use mapping
|
||
|
|
-------------------
|
||
|
|
In most of the other keybrd tutorial examples:
|
||
|
|
* layout and matrix are congruent
|
||
|
|
* active-low keyboard diodes are oriented with cathodes towards the matrix rows
|
||
|
|
(or active-high keyboard diodes are oriented with anodes towards the matrix rows)
|
||
|
|
|
||
|
|
There is no standard way keyboards are manufactured. Some variations are:
|
||
|
|
* irregular matrix
|
||
|
|
* active-low keyboard diodes are oriented with anodes towards the matrix rows
|
||
|
|
* active-high keyboard diodes are oriented with cathodes towards the matrix rows
|
||
|
|
* I/O expander pins connect to matrix out of order
|
||
|
|
|
||
|
|
Any of these variations can use a mapping to align a layout with the matrix.
|
||
|
|
|
||
|
|
Mapping a layout to a matrix
|
||
|
|
----------------------------
|
||
|
|
Modify the basic breadboard keyboard by flipping diodes, so that anodes are towards matrix rows (blue bus).
|
||
|
|
The [keybrd_7a_mapping_single-layer.ino](keybrd_7a_mapping_single-layer/keybrd_7a_mapping_single-layer.ino) sketch will run on the keyboard.
|
||
|
|
Annotations in the sketch explain how mapping from LAYOUT to MATRIX works.
|
||
|
|
|
||
|
|
The [keybrd_7b_mapping_multi-layer.ino](keybrd_7b_mapping_multi-layer/keybrd_7b_mapping_multi-layer.ino) sketch will run on the same keyboard.
|
||
|
|
|
||
|
|
Exercise
|
||
|
|
--------
|
||
|
|
1) Make a keyboard with an irregular matrix.
|
||
|
|
* Modify the basic breadboard keyboard by crossing the columns.
|
||
|
|
* Modify the keybrd_2_single-layer.ino sketch by mapping the layout to the irregular matrix.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
<br>
|
||
|
|
<a rel="license" href="https://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://licensebuttons.net/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="https://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="https://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="https://creativecommons.org/ns" href="https://github.com/wolfv6/keybrd/issues/new" rel="cc:morePermissions">https://github.com/wolfv6/keybrd/issues/new</a>.
|