diff options
| author | Sadeep Madurange <sadeep@asciimx.com> | 2025-10-25 18:19:48 +0800 |
|---|---|---|
| committer | Sadeep Madurange <sadeep@asciimx.com> | 2025-10-25 19:07:22 +0800 |
| commit | 8cd867cd53794386cb9443bfc023fe97c5c5fa47 (patch) | |
| tree | 0f3f076e8b7f542b511d737eaaf3f3ec1cef457d /_site/archive/my-first-pcb | |
| parent | 210a4c8671b368a3a240f9cb7a0bd1718a301523 (diff) | |
| download | www-8cd867cd53794386cb9443bfc023fe97c5c5fa47.tar.gz | |
Render posts.
Diffstat (limited to '_site/archive/my-first-pcb')
| -rw-r--r-- | _site/archive/my-first-pcb/back.jpeg | bin | 0 -> 34023 bytes | |||
| -rw-r--r-- | _site/archive/my-first-pcb/back_design.jpeg | bin | 0 -> 31946 bytes | |||
| -rw-r--r-- | _site/archive/my-first-pcb/front.jpeg | bin | 0 -> 28997 bytes | |||
| -rw-r--r-- | _site/archive/my-first-pcb/front_design.jpeg | bin | 0 -> 32174 bytes | |||
| -rw-r--r-- | _site/archive/my-first-pcb/gerber_back.zip | bin | 0 -> 48217 bytes | |||
| -rw-r--r-- | _site/archive/my-first-pcb/gerber_front.zip | bin | 0 -> 49605 bytes | |||
| -rw-r--r-- | _site/archive/my-first-pcb/index.html | 108 | ||||
| -rw-r--r-- | _site/archive/my-first-pcb/source.tar.gz | bin | 0 -> 6660 bytes |
8 files changed, 108 insertions, 0 deletions
diff --git a/_site/archive/my-first-pcb/back.jpeg b/_site/archive/my-first-pcb/back.jpeg Binary files differnew file mode 100644 index 0000000..f458e69 --- /dev/null +++ b/_site/archive/my-first-pcb/back.jpeg diff --git a/_site/archive/my-first-pcb/back_design.jpeg b/_site/archive/my-first-pcb/back_design.jpeg Binary files differnew file mode 100644 index 0000000..b6c0f5d --- /dev/null +++ b/_site/archive/my-first-pcb/back_design.jpeg diff --git a/_site/archive/my-first-pcb/front.jpeg b/_site/archive/my-first-pcb/front.jpeg Binary files differnew file mode 100644 index 0000000..2b2931f --- /dev/null +++ b/_site/archive/my-first-pcb/front.jpeg diff --git a/_site/archive/my-first-pcb/front_design.jpeg b/_site/archive/my-first-pcb/front_design.jpeg Binary files differnew file mode 100644 index 0000000..f81f09c --- /dev/null +++ b/_site/archive/my-first-pcb/front_design.jpeg diff --git a/_site/archive/my-first-pcb/gerber_back.zip b/_site/archive/my-first-pcb/gerber_back.zip Binary files differnew file mode 100644 index 0000000..26659ad --- /dev/null +++ b/_site/archive/my-first-pcb/gerber_back.zip diff --git a/_site/archive/my-first-pcb/gerber_front.zip b/_site/archive/my-first-pcb/gerber_front.zip Binary files differnew file mode 100644 index 0000000..864334e --- /dev/null +++ b/_site/archive/my-first-pcb/gerber_front.zip diff --git a/_site/archive/my-first-pcb/index.html b/_site/archive/my-first-pcb/index.html new file mode 100644 index 0000000..69b809f --- /dev/null +++ b/_site/archive/my-first-pcb/index.html @@ -0,0 +1,108 @@ +<!DOCTYPE html> +<html> + <head> + <meta charset="utf-8"> + <title>My first PCB</title> + <head> +<meta charset="utf-8"> + <title>My first PCB</title> + <link rel="stylesheet" href="/assets/css/main.css"> + <link rel="stylesheet" href="/assets/css/normalize.css"> + <link rel="stylesheet" href="/assets/css/skeleton.css"> +</head> + + + </head> + <body> + + <div class="container"> + <ul id="navlist" class="left"> + + <li > + <a href="/">hme</a> + </li> + <li > + <a href="/projects/">proj</a> + </li> + <li > + <a href="/about/">abt</a> + </li> + <li><a href="/feed.xml">rss</a></li> + </ul> +</div> + + + + <main> + <div class="container"> + <h2 class="brand center" id="title">MY FIRST PCB</h2> + + <h6 class="center">14 JULY 2025</h5> + + <br> + + <div class="threecol 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: 50%; 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; width: 50%; vertical-align: center; 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: 50%; 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; width: 50%; vertical-align: center; 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="right italics">by W. D. Sadeep Madurange</p> + </div> + </main> + + </body> +</html> diff --git a/_site/archive/my-first-pcb/source.tar.gz b/_site/archive/my-first-pcb/source.tar.gz Binary files differnew file mode 100644 index 0000000..c31aa22 --- /dev/null +++ b/_site/archive/my-first-pcb/source.tar.gz |
