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diff --git a/posts/thors-hammer/index.html b/posts/thors-hammer/index.html new file mode 100644 index 0000000..54c92d2 --- /dev/null +++ b/posts/thors-hammer/index.html @@ -0,0 +1,131 @@ +<!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 | blog.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/blog.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>.<br/> + <a href="/about">About this blog</a>. + </div> + </footer> + </body> +</html> + |