130 lines
4.7 KiB
HTML
130 lines
4.7 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="en-us">
|
|
<head>
|
|
<meta charset="utf-8">
|
|
<meta name="viewport" content="width=device-width, initial-scale=1">
|
|
<title>Thor's Hammer | jaseg.de</title>
|
|
<link rel="stylesheet" href="/css/style.css" />
|
|
<link rel="stylesheet" href="/css/fonts.css" />
|
|
|
|
<header>
|
|
|
|
|
|
<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/atom-one-light.min.css">
|
|
<script src="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/highlight.min.js"></script>
|
|
<script>hljs.initHighlightingOnLoad();</script>
|
|
<nav>
|
|
<ul>
|
|
|
|
|
|
<li class="pull-left ">
|
|
<a href="https://blog.jaseg.de/">/home/jaseg.de</a>
|
|
</li>
|
|
|
|
|
|
|
|
|
|
</ul>
|
|
</nav>
|
|
</header>
|
|
|
|
</head>
|
|
|
|
<body>
|
|
<br/>
|
|
|
|
<div class="article-meta">
|
|
<h1><span class="title">Thor's Hammer</span></h1>
|
|
|
|
<h2 class="date">2018/05/03</h2>
|
|
<p class="terms">
|
|
|
|
|
|
|
|
|
|
|
|
</p>
|
|
</div>
|
|
|
|
|
|
|
|
<main>
|
|
<div class="document">
|
|
|
|
|
|
<p>In case you were having an inferiority complex because your friends' IBM Model M keyboards are so much louder than the
|
|
shitty rubber dome freebie you got with your pc... Here's the solution: Thor's Hammer, a simple typing cadence enhancer
|
|
for <a class="reference external" href="https://en.wikipedia.org/wiki/PS/2_port">PS/2</a> keyboards.</p>
|
|
<figure>
|
|
<video controls loop>
|
|
<source src="video/thors_hammer.mov" type="video/h264">
|
|
<source src="video/thors_hammer.webm" type="video/webm">
|
|
Your browser does not support the HTML5 video tag.
|
|
</video>
|
|
<figcaption>A demonstration of the completed project.
|
|
|
|
<a href="video/thors_hammer.mov">h264 download</a> /
|
|
<a href="video/thors_hammer.webm">webm download</a>
|
|
</figcaption>
|
|
</figure><p>The connects to the keyboard's PS/2 clock line and briefly actuates a large solenoid on each key press. An interesting
|
|
fact about PS/2 is that the clock line is only active as long as either the host computer or the input device actually
|
|
want to send data. In case of a keyboard that's the case when a key is pressed or when the host changes the keyboard's
|
|
LED state, otherwise the clock line is silent. We ignore the LED activity for now as it's generally coupled to key
|
|
presses. By just triggering an NE555 configured as astable flipflop we can stretch each train of clock pulses to a
|
|
pulse a few tens of milliseconds long that is enough to actuate the solenoid.</p>
|
|
<figure>
|
|
<img src="images/thors_hammer_schematic.jpg" alt="The schematic of the PS2 driver">
|
|
<figcaption>The schematic of the driver stretching the PS/2 clock pulses to drive the solenoid.</figcaption>
|
|
</figure><p>Since PS/2 sends each key press and key release separately this circuit will pulse twice per keystroke. It would be
|
|
possible to ignore one of them but I figure the added noise just adds to the experience.</p>
|
|
<p>Built on a breadboard, the circuit looks like this.</p>
|
|
<figure>
|
|
<img src="images/thors_hammer_breadboard.jpg" alt="The circuit built on a breadboard">
|
|
<figcaption>The completed circuit built up on a breadboard and attached to a keyboard.</figcaption>
|
|
</figure><p>Since my solenoid did not have a tensioning spring I used a rubber band and some vinyl tape to make an adjustable
|
|
tensioner. The small orange USB hub serves as an end-stop because I had nothing else of the right shape. The sound and
|
|
resonance of the thing can be adjusted to taste by moving the end stop, adjusting the tensioning rubber and tuning the
|
|
excitation duration using the potentiometer. My particular solenoid was a bit slow so I added some pieces of circuit
|
|
board as shims between the plunger and the case to limit the plunger's travel inside the solenoid core.</p>
|
|
</div>
|
|
</main>
|
|
|
|
<footer>
|
|
|
|
<script>
|
|
(function() {
|
|
function center_el(tagName) {
|
|
var tags = document.getElementsByTagName(tagName), i, tag;
|
|
for (i = 0; i < tags.length; i++) {
|
|
tag = tags[i];
|
|
var parent = tag.parentElement;
|
|
|
|
if (parent.childNodes.length === 1) {
|
|
|
|
if (parent.nodeName === 'A') {
|
|
parent = parent.parentElement;
|
|
if (parent.childNodes.length != 1) continue;
|
|
}
|
|
if (parent.nodeName === 'P') parent.style.textAlign = 'center';
|
|
}
|
|
}
|
|
}
|
|
var tagNames = ['img', 'embed', 'object'];
|
|
for (var i = 0; i < tagNames.length; i++) {
|
|
center_el(tagNames[i]);
|
|
}
|
|
})();
|
|
</script>
|
|
|
|
|
|
<div id="license-info">
|
|
©2020 by Jan Götte. This work is licensed under
|
|
<a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">CC-BY-NC-SA 4.0</a>.
|
|
</div>
|
|
<div id="imprint-info">
|
|
<a href="/imprint">Impressum und Haftungsausschluss und Datenschutzerklärung</a>.
|
|
</div>
|
|
</footer>
|
|
</body>
|
|
</html>
|
|
|