wip: Unix desktop.

author: Sadeep Madurange <sadeep@asciimx.com> 2025-11-02 15:12:54 +0800
committer: Sadeep Madurange <sadeep@asciimx.com> 2025-11-02 15:12:54 +0800
commit: 3b63c5139ca9a34fa79bc2eb132ecfd71897dc7e (patch)
tree: a2f060fb2deb2bfd3f541f46e6a842fac5f9c752 /_site/projects
parent: eb6497e805627137e15bf30d3ec46fb510103f56 (diff)
download: www-3b63c5139ca9a34fa79bc2eb132ecfd71897dc7e.tar.gz
14 files changed, 111 insertions, 77 deletions
diff --git a/_site/projects/desktop-unix/dotfiles.tar.gz b/_site/projects/desktop-unix/dotfiles.tar.gz
deleted file mode 100644
index c6774c4..0000000
--- a/_site/projects/desktop-unix/dotfiles.tar.gz
+++ /dev/null
diff --git a/_site/projects/desktop-unix/index.html b/_site/projects/desktop-unix/index.html
deleted file mode 100644
index 53c9859..0000000
--- a/_site/projects/desktop-unix/index.html
+++ /dev/null
@@ -1,75 +0,0 @@
-<!DOCTYPE html>
-<html>
-  <head>
-    <meta charset="utf-8">
-    <title>Desktop Unix</title>
-
-    <head>
-  <meta charset="utf-8">
-  <meta name="viewport" content="width=device-width, initial-scale=1">
-  <title>Desktop Unix</title>
-  <link rel="stylesheet" href="/assets/css/main.css">
-  <link rel="stylesheet" href="/assets/css/skeleton.css">
-</head>
-
-
-
-  </head>
-  <body>
-
-    <div class="container">
-  <ul id="navlist" class="left">
-    
-    <li >
-      <a href="/" class="link-decor-none">hme</a>
-    </li>
-    <li >
-      <a href="/archive/" class="link-decor-none">blg</a>
-    </li>
-    <li class="active">
-      <a href="/projects/" class="link-decor-none">poc</a>
-    </li>
-    <li >
-      <a href="/about/" class="link-decor-none">abt</a>
-    </li>
-    <li><a href="/feed.xml" class="link-decor-none">rss</a></li>
-  </ul>
-</div>
-
-
-
-    <main>
-      <div class="container">
-        <h2 class="center" id="title">DESKTOP UNIX</h2>
-        <h6 class="center">21 SEPTEMBER 2025</h5>
-        <br>
-        <div class="twocol justify"><p>The year 2020 transformed my personal computing experience. In March 2020, I
-stumbled upon Arch Linux and discovered that I could customize my desktop
-environment to look and work any way I liked. I exercised that newfound freedom
-to create a Matrix-themed setup:</p>
-
-<p><img src="linux.png" alt="Arch Linux" /></p>
-
-<p>The system employs the X display server and the i3 window manager. The terminal
-emulator used is Urxvt. The translucent effect is achieved with the help of the
-Xcompmgr compositor. This sort of setup was popular among minimalist Linux
-users.</p>
-
-<p>In February 2024, I switched to an OpenBSD system with Xenocara (the OpenBSD
-build of X display server) as the display server and i3 as the window manager:</p>
-
-<p><img src="openbsd.png" alt="OpenBSD i3" /></p>
-
-<p>Unlike Linux, OpenBSD includes a coherent desktop environment out of the box.
-Except for the window manager, for which I prefer a tiling one, I’m now using
-the default OpenBSD setup. For the window manager, I use dwm from the Suckless
-team.</p>
-
-<p>Files: <a href="dotfiles.tar.gz">dotfiles.tar.gz</a></p>
-</div>
-        <p class="post-author right">by Wickramage Don Sadeep Madurange</p>
-      </div>
-    </main>
-
-  </body>
-</html>
diff --git a/_site/projects/desktop-unix/linux.png b/_site/projects/desktop-unix/linux.png
deleted file mode 100644
index 40bc33b..0000000
--- a/_site/projects/desktop-unix/linux.png
+++ /dev/null
diff --git a/_site/projects/desktop-unix/openbsd.png b/_site/projects/desktop-unix/openbsd.png
deleted file mode 100644
index d7489f7..0000000
--- a/_site/projects/desktop-unix/openbsd.png
+++ /dev/null
diff --git a/_site/projects/index.html b/_site/projects/index.html
index c18a920..6d0e0c9 100644
--- a/_site/projects/index.html
+++ b/_site/projects/index.html
@@ -79,8 +79,8 @@
       
           <td class="project-item">
             
-            <img src="desktop-unix/linux.png" alt="Desktop Unix">
-            <h5><a href="desktop-unix" class="link-decor-none">Desktop Unix</a></h5>
+            <img src="my-first-pcb/thumb.jpeg" alt="My first PCB">
+            <h5><a href="my-first-pcb" class="link-decor-none">My first PCB</a></h5>
           </td>
       
           <td class="project-item">
diff --git a/_site/projects/my-first-pcb/back.jpeg b/_site/projects/my-first-pcb/back.jpeg
new file mode 100644
index 0000000..f458e69
--- /dev/null
+++ b/_site/projects/my-first-pcb/back.jpeg
diff --git a/_site/projects/my-first-pcb/back_design.jpeg b/_site/projects/my-first-pcb/back_design.jpeg
new file mode 100644
index 0000000..b6c0f5d
--- /dev/null
+++ b/_site/projects/my-first-pcb/back_design.jpeg
diff --git a/_site/projects/my-first-pcb/front.jpeg b/_site/projects/my-first-pcb/front.jpeg
new file mode 100644
index 0000000..2b2931f
--- /dev/null
+++ b/_site/projects/my-first-pcb/front.jpeg
diff --git a/_site/projects/my-first-pcb/front_design.jpeg b/_site/projects/my-first-pcb/front_design.jpeg
new file mode 100644
index 0000000..f81f09c
--- /dev/null
+++ b/_site/projects/my-first-pcb/front_design.jpeg
diff --git a/_site/projects/my-first-pcb/gerber_back.zip b/_site/projects/my-first-pcb/gerber_back.zip
new file mode 100644
index 0000000..26659ad
--- /dev/null
+++ b/_site/projects/my-first-pcb/gerber_back.zip
diff --git a/_site/projects/my-first-pcb/gerber_front.zip b/_site/projects/my-first-pcb/gerber_front.zip
new file mode 100644
index 0000000..864334e
--- /dev/null
+++ b/_site/projects/my-first-pcb/gerber_front.zip
diff --git a/_site/projects/my-first-pcb/index.html b/_site/projects/my-first-pcb/index.html
new file mode 100644
index 0000000..aa77519
--- /dev/null
+++ b/_site/projects/my-first-pcb/index.html
@@ -0,0 +1,109 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title>My first PCB</title>
+
+    <head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>My first PCB</title>
+  <link rel="stylesheet" href="/assets/css/main.css">
+  <link rel="stylesheet" href="/assets/css/skeleton.css">
+</head>
+
+
+
+  </head>
+  <body>
+
+    <div class="container">
+  <ul id="navlist" class="left">
+    
+    <li >
+      <a href="/" class="link-decor-none">hme</a>
+    </li>
+    <li >
+      <a href="/archive/" class="link-decor-none">blg</a>
+    </li>
+    <li class="active">
+      <a href="/projects/" class="link-decor-none">poc</a>
+    </li>
+    <li >
+      <a href="/about/" class="link-decor-none">abt</a>
+    </li>
+    <li><a href="/feed.xml" class="link-decor-none">rss</a></li>
+  </ul>
+</div>
+
+
+
+    <main>
+      <div class="container">
+        <h2 class="center" id="title">MY FIRST PCB</h2>
+        <h6 class="center">14 JULY 2025</h5>
+        <br>
+        <div class="twocol justify"><p>In 2023, I started tinkering with DIY electronics as a hobby. Until now, I’ve
+been using development boards like the Arduino Uno and ESP-32-WROOM so that I
+can focus on the software. Recently, I decided to step outside of my comfort
+zone and design a PCB from scratch for a door lock I’m working on.</p>
+
+<p>The lock comprises two subsystems: a fingerprint sensor in front of the door
+and a servo connected to the physical lock behind the door. The fingerprint
+sensor authenticates the person and signals the servo behind the door to unlock
+the door over an encrypted RF channel.</p>
+
+<table style="border: none; width: 100%">
+  <tr style="border: none;">
+    <td style="border: none; width: 49.5%; vertical-align: top; text-align: center;">
+      <img src="front_design.jpeg" alt="Design (front)" style="width: 100%" />
+      <p>Footprint (front)</p>
+    </td>
+    <td style="border: none; vertical-align: top; text-align: center;">
+      <img src="front.jpeg" alt="PCB (front)" style="width: 100%" />
+      <p>PCB (front)</p>
+    </td>
+  </tr>
+  <tr style="border: none;">
+    <td style="border: none; width: 49.5%; vertical-align: top; text-align: center;">
+      <img src="back_design.jpeg" alt="Design (back)" style="width: 100%" />
+      <p>Footprint (back)</p>
+    </td>
+    <td style="border: none; vertical-align: top; text-align: center;">
+      <img src="back.jpeg" alt="PCB (back)" style="width: 100%" />
+      <p>PCB (back)</p>
+    </td>
+  </tr>
+</table>
+
+<p>The PCBs have two layers. A copper region serves as the ground plane. The 0.3
+mm wide 1 oz/ft<sup>2</sup> copper traces can carry up to 500 mA (the tracks
+connecting the power source and the linear regulators have a width of 0.5 mm).
+Both subsystems were functional. I was able to control the servo reliably using
+the fingerprint sensor.</p>
+
+<p>The designs aren’t without flaws, however. The main shortcoming of the circuits
+is that they draw significant amounts of quiescent currents despite employing
+sleep modes. The linear regulators were a poor choice as they dissipate too
+much heat. The fingerprint sensor and the servo draw 13.8 mA (3.3 V) and 4.6 mA
+(5 V) respectively, as long as they are connected to the power supply.</p>
+
+<p>Although the circuit didn’t draw more than 200 mA without a load, the servo
+under load could draw up to 600 mA. I’m sailing too close to the wind with 0.3
+mm copper traces. Instead, 0.4 mm wide 2 oz/ft<sup>2</sup> traces would have
+been safer.</p>
+
+<p>I’m working on improving the design to reduce idle current consumption and
+extend the battery life. Despite its deficiencies, this was my first PCB
+design, and I’m glad that it worked as well as it did. Custom PCB design marks
+an important milestone in my DIY electronics journey.</p>
+
+<p>Files: <a href="gerber_back.zip">gerber_back.zip</a>, <a href="gerber_front.zip">gerber_front.zip</a>,
+       <a href="source.tar.gz">source.tar.gz</a></p>
+</div>
+        <p class="post-author right">by Wickramage Don Sadeep Madurange</p>
+      </div>
+    </main>
+
+  </body>
+</html>
diff --git a/_site/projects/my-first-pcb/source.tar.gz b/_site/projects/my-first-pcb/source.tar.gz
new file mode 100644
index 0000000..c31aa22
--- /dev/null
+++ b/_site/projects/my-first-pcb/source.tar.gz
diff --git a/_site/projects/my-first-pcb/thumb.jpeg b/_site/projects/my-first-pcb/thumb.jpeg
new file mode 100644
index 0000000..be7143d
--- /dev/null
+++ b/_site/projects/my-first-pcb/thumb.jpeg
author	Sadeep Madurange <sadeep@asciimx.com>	2025-11-02 15:12:54 +0800
committer	Sadeep Madurange <sadeep@asciimx.com>	2025-11-02 15:12:54 +0800
commit	3b63c5139ca9a34fa79bc2eb132ecfd71897dc7e (patch)
tree	a2f060fb2deb2bfd3f541f46e6a842fac5f9c752 /_site/projects
parent	eb6497e805627137e15bf30d3ec46fb510103f56 (diff)
download	www-3b63c5139ca9a34fa79bc2eb132ecfd71897dc7e.tar.gz