qmk_firmware/assets/how_a_matrix_works.md.EVA8jmAG.js

import { _ as _export_sfc, c as createElementBlock, o as openBlock, a8 as createStaticVNode } from "./chunks/framework.B9AX-CPi.js";
const __pageData = JSON.parse('{"title":"How a Keyboard Matrix Works","description":"","frontmatter":{},"headers":[],"relativePath":"how_a_matrix_works.md","filePath":"how_a_matrix_works.md"}');
const _sfc_main = { name: "how_a_matrix_works.md" };
const _hoisted_1 = /* @__PURE__ */ createStaticVNode('<h1 id="how-a-keyboard-matrix-works" tabindex="-1">How a Keyboard Matrix Works <a class="header-anchor" href="#how-a-keyboard-matrix-works" aria-label="Permalink to &quot;How a Keyboard Matrix Works&quot;">​</a></h1><p>Keyboard switch matrices are arranged in rows and columns. Without a matrix circuit, each switch would require its own wire directly to the controller.</p><p>When the circuit is arranged in rows and columns, if a key is pressed, a column wire makes contact with a row wire and completes a circuit. The keyboard controller detects this closed circuit and registers it as a key press.</p><p>The microcontroller will be set up via the firmware to send a logical 1 to the columns, one at a time, and read from the rows, all at once - this process is called matrix scanning. The matrix is a bunch of open switches that, by default, don&#39;t allow any current to pass through - the firmware will read this as no keys being pressed. As soon as you press one key down, the logical 1 that was coming from the column the keyswitch is attached to gets passed through the switch and to the corresponding row - check out the following 2x2 example:</p><div class="language- vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang"></span><pre class="shiki shiki-themes github-light github-dark vp-code"><code><span class="line"><span>        Column 0 being scanned     Column 1 being scanned</span></span>\n<span class="line"><span>                  x                                   x</span></span>\n<span class="line"><span>                 col0     col1              col0     col1</span></span>\n<span class="line"><span>                  |        |                 |        |</span></span>\n<span class="line"><span>        row0 ---(key0)---(key1)    row0 ---(key0)---(key1)</span></span>\n<span class="line"><span>                  |        |                 |        |</span></span>\n<span class="line"><span>        row1 ---(key2)---(key3)    row1 ---(key2)---(key3)</span></span></code></pre></div><p>The <code>x</code> represents that the column/row associated has a value of 1, or is HIGH. Here, we see that no keys are being pressed, so no rows get an <code>x</code>. For one keyswitch, keep in mind that one side of the contacts is connected to its row, and the other, its column.</p><p>When we press <code>key0</code>, <code>col0</code> gets connected to <code>row0</code>, so the values that the firmware receives for that row is <code>0b01</code> (the <code>0b</code> here means that this is a bit value, meaning all of the following digits are bits - 0 or 1 - and represent the keys in that column). We&#39;ll use this notation to show when a keyswitch has been pressed, to show that the column and row are being connected:</p><div class="language- vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang"></span><pre class="shiki shiki-themes github-light github-dark vp-code"><code><span class="line"><span>        Column 0 being scanned     Column 1 being scanned</span></span>\n<span class="line"><span>                  x                                   x</span></span>\n<span class="line"><span>                 col0     col1              col0     col1</span></span>\n<span class="line"><span>                  |        |                 |        |</span></span>\n<span class="line"><span>      x row0 ---(-+-0)---(key1)    row0 ---(-+-0)---(key1)</span></span>\n<span class="line"><span>                  |        |                 |        |</span></span>\n<span class="line"><span>        row1 ---(key2)---(key3)    row1 ---(key2)---(key3)</span></span></code></pre></div><p>We can now see that <code>row0</code> has an <code>x</code>, so has the value of 1. As a whole, the data the firmware receives when <code>key0</code> is pressed is:</p><div class="language- vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang"></span><pre class="shiki shiki-themes github-light github-dark vp-code"><code><span class="line
const _hoisted_25 = [
  _hoisted_1
];
function _sfc_render(_ctx, _cache, $props, $setup, $data, $options) {
  return openBlock(), createElementBlock("div", null, _hoisted_25);
}
const how_a_matrix_works = /* @__PURE__ */ _export_sfc(_sfc_main, [["render", _sfc_render]]);
export {
  __pageData,
  how_a_matrix_works as default
};