From 8cbe75f0047732c865f58e2f847a5ffafe066e71 Mon Sep 17 00:00:00 2001 From: Sadeep Madurange Date: Sat, 20 Dec 2025 11:25:26 +0800 Subject: Change projects to poc and blog to log. --- _site/projects/bumblebee/bee.mp4 | Bin 2352029 -> 0 bytes _site/projects/bumblebee/index.html | 103 -------------- _site/projects/bumblebee/poster.png | Bin 18024 -> 0 bytes _site/projects/bumblebee/thumb_sm.png | Bin 6189 -> 0 bytes _site/projects/e-reader/circuit.svg | 145 ------------------- _site/projects/e-reader/ereader.mp4 | Bin 3101166 -> 0 bytes _site/projects/e-reader/index.html | 148 -------------------- _site/projects/e-reader/poster.png | Bin 674187 -> 0 bytes _site/projects/e-reader/source.tar.gz | Bin 14304 -> 0 bytes _site/projects/e-reader/thumb_sm.png | Bin 240117 -> 0 bytes _site/projects/etlas/circuit.svg | 105 -------------- _site/projects/etlas/dash.jpg | Bin 85874 -> 0 bytes _site/projects/etlas/etlas_arch.png | Bin 47732 -> 0 bytes _site/projects/etlas/index.html | 166 ---------------------- _site/projects/etlas/pcb.jpg | Bin 75769 -> 0 bytes _site/projects/etlas/schematic.svg | 4 - 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- - - - Bumblebee: browser automation - - - - - Bumblebee: browser automation - - - - - - - - - - - - - -
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BUMBLEBEE: BROWSER AUTOMATION

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02 APRIL 2025
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-

Bumblebee is a tool I built for one of my employers to automate the generation -of web scraping scripts.

- - - -

In 2024, we were tasked with collecting market data using various methods, -including scraping data from authorized websites for traders’ use.

- -

Manual authoring of such scripts took time. The scripts were often brittle due -to the complexity of the modern web, and they lacked optimizations such as -bypassing the UI and retrieving the data files directly when possible, which -would have significantly reduced our compute costs.

- -

To alleviate these challenges, I, with the help of a colleague, Andy Zhang, -built Bumblebee: a web browser powered by C# Windows Forms, Microsoft Edge WebView2, and -the Scintilla.NET text editor.

- -

Bumblebee works by injecting a custom JavaScript program that intercepts -client-side events and sends them to Bumblebee for analysis. In addition to -front-end events, Bumblebee also captures internal browser events, which it -then interprets to generate code in real time. Note that we developed Bumblebee -before the advent of now-popular LLMs. Bumblebee supports dynamic websites, -pop-ups, developer tools, live manual override, event debouncing, and filtering -hidden elements and scripts.

- -

Before settling on a desktop application, we contemplated designing Bumblebee -as a browser extension. We chose the desktop app because extensions don’t offer -the deep, event-based control we needed. Besides, the company’s security -policy, which prohibited browser extensions, would have complicated the -deployment of an extension-based solution. My first prototype used a C# binding -of the Chromium project. WebView’s more intuitive API and its seamless -integration with Windows Forms led us to choose it over the Chromium wrapper.

- -

What began as a personal side project to improve my own workflow enabled us to -collectively improve the quality of our web scripts at a much larger scale. -Bumblebee predictably reduced the time we spent on authoring scripts from hours -to a few minutes.

- -
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by W. D. Sadeep Madurange

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© ASCIIMX - 2025

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- - - - diff --git a/_site/projects/bumblebee/poster.png b/_site/projects/bumblebee/poster.png deleted file mode 100644 index 6dc955e..0000000 Binary files a/_site/projects/bumblebee/poster.png and /dev/null differ diff --git a/_site/projects/bumblebee/thumb_sm.png b/_site/projects/bumblebee/thumb_sm.png deleted file mode 100644 index f7cfbf3..0000000 Binary files a/_site/projects/bumblebee/thumb_sm.png and /dev/null differ diff --git a/_site/projects/e-reader/circuit.svg b/_site/projects/e-reader/circuit.svg deleted file mode 100644 index fd7508b..0000000 --- a/_site/projects/e-reader/circuit.svg +++ /dev/null @@ -1,145 +0,0 @@ - - - - - - - - - - - 10 kΩ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 - 2 - 3 - 4 - - - - - - - - - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - - - - - 5 - 6 - 7 - 8 - BUS - E-Paper Display HAT - - - CS - - DC - - DIN - - CLK - - BUSY - - RST - - GND - - VCC - - ESP-WROOM-32 - - IO21 - - - IO5 - - - IO16 - - - IO23 - - - IO18 - - - IO22 - - - IO4 - - - IO2 - - - GND - - - 3V3 - - - GND - - - IO15 - - - - \ No newline at end of file diff --git a/_site/projects/e-reader/ereader.mp4 b/_site/projects/e-reader/ereader.mp4 deleted file mode 100644 index 89e05eb..0000000 Binary files a/_site/projects/e-reader/ereader.mp4 and /dev/null differ diff --git a/_site/projects/e-reader/index.html b/_site/projects/e-reader/index.html deleted file mode 100644 index fb48a9d..0000000 --- a/_site/projects/e-reader/index.html +++ /dev/null @@ -1,148 +0,0 @@ - - - - - Experimental e-reader - - - - - Experimental e-reader - - - - - - - - - - - - - -
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EXPERIMENTAL E-READER

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24 OCTOBER 2023
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-

This project features an experimental e-reader powered by an ESP-WROOM-32 -development board and a 7.5-inch Waveshare -e-paper display built with the intention of learning about e-paper displays.

- - - -

Introduction

- -

The prototype e-reader comprises an ESP32 microcontroller, an e-paper display -HAT, and three buttons: yellow, blue, and white for turning the page backwards, -forwards, and putting the device to sleep, respectively. The prototype does not -store books on the microcontroller. It streams books from a server over HTTP. -The e-reader employs RTC memory to record the reading progress between -sessions.

- -

The most formidable challenge when trying to build an e-reader with an ESP32 is -its limited memory and storage. My ESP-WROOM-32 has a total of 512KB of SRAM -and 4MB of flash memory, which the freeRTOS, ESP-IDF, and the e-reader -application must share. To put things into perspective, a Kindle Paperwhite has -at least 256MB of memory and 8GB of storage. That is 500x more memory than what -I’d have to work with.

- -

Despite its size, as microcontrollers go, ESP32 is a powerful system-on-a-chip -with a 160MHz dual-core processor and integrated WiFi. So, I thought it’d be -amusing to embrace the constraints and build my e-reader using a $5 MCU and the -power of C programming.

- -

The file format

- -

The file format dictates the complexity of the embedded software. So, I’ll -begin there. The e-reader works by downloading and rendering a rasterized -monochrome image of a page (a .ebm file).

- -

The EBM file contains a series of bitmaps, one for each page of the book. The -dimensions of each bitmap are equal to the size of the display. Each byte of -the bitmap encodes information for rendering eight pixels. For my display, -which has a resolution of 480x800, the bitmaps are laid out along 48KB -boundaries. This simple file format lends well to HTTP streaming, which is its -main advantage, as we will soon see.

- -

The pdftoebm.py script enclosed in the tarball at the end of the page converts -PDF documents to EBM files.

- -

How does it work?

- -

As the e-reader has no storage, it can’t store books locally. Instead, it -downloads pages of the EBM file over HTTP from the location pointed to by the -EBM_ARCH_URL setting in the Kconfig.projbuild file on demand. To read a -different book, we have to replace the old file with the new one or change the -EBM_ARCH_URL value. The latter requires us to recompile the embedded -software.

- -

Upon powering up, the e-reader checks the reading progress stored in the RTC -memory. It then downloads three pages (current, previous, and next) to a -circular buffer in DMA-capable memory. When the user turns a page by pressing a -button, one of the microprocessor’s two cores transfers it from the buffer to -the display over a Serial Peripheral Interface (SPI). The other downloads a new -page in the background. I used the ESP-IDF task API to schedule the two tasks -on different cores of the multicore processor to make the reader more -responsive.

- -

I designed the EBM format with HTTP streaming in mind. Since the pages are laid -out in the EBM file along predictable boundaries, the e-reader can request -pages by specifying the offset and the chunk size in the HTTP Range header. Any -web server will process this request without custom logic.

- -

Epilogue

- -

My fascination with e-paper began back in 2017, when I was tasked with -installing a few displays in a car park. Having no idea how they worked, I -remember watching the languid screens refresh like a Muggle witnessing magic. -This project was born out of that enduring curiosity and love of e-paper -technology.

- -

Why did I go to the trouble of building a rudimentary e-reader when I could -easily buy a more capable commercial e-reader? First of all, it’s to prove to -myself that I can. More importantly, there’s a quiet satisfaction to reading on -hardware you built yourself. You are no longer the powerless observer watching -the magic happen from the sidelines. You become the wizard who makes the -invisible particles swirl into form by whispering C to them. There’s only one -way to experience that.

- -

Files: source.tar.gz

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by W. D. Sadeep Madurange

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© ASCIIMX - 2025

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- - - - diff --git a/_site/projects/e-reader/poster.png b/_site/projects/e-reader/poster.png deleted file mode 100644 index 1e222d2..0000000 Binary files a/_site/projects/e-reader/poster.png and /dev/null differ diff --git a/_site/projects/e-reader/source.tar.gz b/_site/projects/e-reader/source.tar.gz deleted file mode 100644 index 3e343a7..0000000 Binary files a/_site/projects/e-reader/source.tar.gz and /dev/null differ diff --git a/_site/projects/e-reader/thumb_sm.png b/_site/projects/e-reader/thumb_sm.png deleted file mode 100644 index 7c971e8..0000000 Binary files a/_site/projects/e-reader/thumb_sm.png and /dev/null differ diff --git a/_site/projects/etlas/circuit.svg b/_site/projects/etlas/circuit.svg deleted file mode 100644 index 6255045..0000000 --- a/_site/projects/etlas/circuit.svg +++ /dev/null @@ -1,105 +0,0 @@ - - - - - - - - - - - - - - - - AM2302 - - - DATA - - GND - - VCC - E-Paper display HAT - - - CS - - DC - - DIN - - CLK - - BUSY - - RST - - PWR - - GND - - VCC - - - - - - - - - - - - - - 1 - 2 - 3 - 4 - - - - - 1 - 2 - 3 - 4 - - ESP32 Mini NodeMCU D1 - - IO19 - - - IO15 - - - GND - - - IO27 - - - IO14 - - - IO13 - - - IO25 - - - IO26 - - - IO16 - - - GND - - - 3V3 - - - \ No newline at end of file diff --git a/_site/projects/etlas/dash.jpg b/_site/projects/etlas/dash.jpg deleted file mode 100644 index cf4efc6..0000000 Binary files a/_site/projects/etlas/dash.jpg and /dev/null differ diff --git a/_site/projects/etlas/etlas_arch.png b/_site/projects/etlas/etlas_arch.png deleted file mode 100644 index 241e9f1..0000000 Binary files a/_site/projects/etlas/etlas_arch.png and /dev/null differ diff --git a/_site/projects/etlas/index.html b/_site/projects/etlas/index.html deleted file mode 100644 index ae30cb6..0000000 --- a/_site/projects/etlas/index.html +++ /dev/null @@ -1,166 +0,0 @@ - - - - - Etlas: e-paper dashboard - - - - - Etlas: e-paper dashboard - - - - - - - - - - - - - -
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ETLAS: E-PAPER DASHBOARD

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05 SEPTEMBER 2024
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Etlas is a news, stock market, and weather tracker powered by an ESP32 NodeMCU -D1, featuring a 7.5-inch Waveshare e-paper display and a -DHT22 sensor module.

- - - - - - -
frontback
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The top-left panel shows two weeks of end-of-day prices—the maximum the ESP32’s -SRAM can hold—from the Polygon.io API. The price feed is relayed through a -FastCGI-wrapped Flask app hosted on a VPS. This lets me configure stock symbols -in its application settings. The app cycles through them as requests come in -from the ESP32. Running the Flask app as a FastCGI process while exposing it -via httpd with htpasswd authentication keeps the server code simple and secure.

- -

The following diagram outlines the Etlas’s overall system architecture.

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architecture

- -

The more prominent panel on the right of the display shows local and world news -from Channel NewsAsia. The MCU downloads and parses XML data from the RSS feed -directly before rendering it to the display. The character glyphs used are -stored as bitmaps in the sprites directory. I skipped the proxy for news to -avoid writing more server code, but in hindsight it limits the feeds Etlas can -handle. I will fix this in a future version.

- -

The middle and bottom right panels display the temperature and relative -humidity from the DHT22 sensor. The DHT22 uses pulse-width modulation to -transmit data to the host. The 26µs, 50µs, and 70µs pulses are too fast for the -ESP32 to measure reliably with standard APIs. Instead, the driver compares -relative pulse widths to differentiate zeros from ones:

- -
static inline int dht_await_pin_state(int state, int timeout)
-{
-    int t;
-    static const uint16_t delta = 1;
-
-    for (t = 0; t < timeout; t += delta) {
-        ets_delay_us(delta);
-        if (gpio_get_level(DHT_PIN) == state)
-          return t;
-    }
-    return 0;
-}
-
-static inline int dht_get_raw_data(unsigned char buf[DHT_DATA_LEN])
-{
-    int rc;
-    unsigned char i, pwl, pwh;
-
-    gpio_set_level(DHT_PIN, 0);
-    ets_delay_us(1100);
-    gpio_set_level(DHT_PIN, 1);
-
-    if (!dht_await_pin_state(0, 40)) {
-        rc = 1;
-        xQueueSend(dht_evt_queue, &rc, (TickType_t) 0);
-        return 0;
-    }
-    if (!dht_await_pin_state(1, 80)) {
-        rc = 2;
-        xQueueSend(dht_evt_queue, &rc, (TickType_t) 0);
-        return 0;
-    }
-    if (!dht_await_pin_state(0, 80)) {
-        rc = 3;
-        xQueueSend(dht_evt_queue, &rc, (TickType_t) 0);
-        return 0;
-    }
-
-    for (i = 0; i < DHT_DATA_LEN; i++) {
-        if (!(pwl = dht_await_pin_state(1, 50))) {
-            rc = 4;
-            xQueueSend(dht_evt_queue, &rc, (TickType_t) 0);
-            return 0;
-        }
-        if (!(pwh = dht_await_pin_state(0, 70))) {
-            rc = 5;
-            xQueueSend(dht_evt_queue, &rc, (TickType_t) 0);
-            return 0;
-        }
-        buf[i] = pwh > pwl;
-    }
-    return 1;
-}
-
- -

I ported this implementation from ESP8266 -to ESP32—all credit for the algorithm belongs to them.

- -

Etlas is a networked embedded system. All acquisition, processing, and -rendering of data are performed on the ESP32’s 160MHz microprocessor using less -than 512KB of SRAM. The embedded software that makes this possible is written -in C using ESP-IDF v5.2.1. The e-paper display driver is derived from Waveshare -examples for Arduino and STM32 -platforms.

- -

Etlas has been running reliably for over a year since August 2024.

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Files: source.tar.gz

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by W. D. Sadeep Madurange

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© ASCIIMX - 2025

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- - - - diff --git a/_site/projects/etlas/pcb.jpg b/_site/projects/etlas/pcb.jpg deleted file mode 100644 index fcb40fa..0000000 Binary files a/_site/projects/etlas/pcb.jpg and /dev/null differ diff --git a/_site/projects/etlas/schematic.svg b/_site/projects/etlas/schematic.svg deleted file mode 100644 index 3070dd1..0000000 --- a/_site/projects/etlas/schematic.svg +++ /dev/null @@ -1,4 +0,0 @@ - - - -152726131425193V3GND
ESP32 Mini NodeMCU D1
ESP32 Mini NodeMCU D1
DHT22
DHT22
E-paper HAT
E-paper HAT
3.3V
3.3V
3.3V
3.3V
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DC
RST
RST
CLK
CLK
MOSY
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DATA
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FINGERPRINT DOOR LOCK

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03 OCTOBER 2025
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This project features a fingerprint door lock powered by an ATmega328P -microcontroller.

- - - -

Overview

- -

The lock comprises three subsystems: the ATmega328P microcontroller, an R503 -fingerprint sensor, and an FS5106B high-torque servo. The sensor mounted on the -front surface of the door enables users to unlock it from the outside. The -servo is attached to the interior door knob. The MCU must be installed at the -back of the door to prevent unauthorized users from tampering with it.

- -

When no one is interacting with the lock, the MCU is in deep sleep. The sensor -and the servo each draw 13.8mA and 4.6mA of quiescent currents. To prevent this -idle current draw, the MCU employs MOSFETs to cut off power to them before -entering deep sleep. Doing so is crucial for conserving the battery.

- -

Without power, the sensor remains in a low-power state, drawing approximately -2.9μA through a separate power rail. When a finger comes into contact with the -sensor, the sensor triggers a pin change interrupt, waking up the MCU. The MCU -activates a MOSFET, which in turn activates the sensor. Over UART, the MCU -unlocks the sensor and issues commands to scan and match the fingerprint.

- -

If the fingerprint matches an enrolled fingerprint, the MCU activates the blue -LED on the sensor, turns on the MOSFET connected to the servo, and sends a PWM -signal to the servo to unlock the door. Otherwise, the MCU activates the red -LED on the sensor. Finally, the MCU deactivates the MOSFETS and goes back to -sleep.

- -

Embedded software

- -

The embedded software, written in C, includes a driver for the sensor, servo -control routines, and a battery monitoring system.

- -

In addition to controlling the sensor and the servo, the program strives to -maintain precise control over the microcontroller’s sleep modes, as well as -when the peripherals are activated and for how long they remain active. I -thoroughly enjoyed writing the embedded software. There’s something magical -about being able to alter the physical world around you by uttering a few lines -of C code.

- -

The source code of the project, which includes a driver for the R503 -fingerprint sensor module, is enclosed in the tarball linked at the end of the -page.

- -

The PCB

- -

For this project, I designed a custom PCB and had it fabricated by JLCPCB. Like -the software, the circuit is primarily concerned with optimizing power -consumption and extending battery life.

- - - - - - - - - -
- PCB - - Design -
- PCB footprint -
- -

Consequently, the principal components of the circuit are the 2N7000 and -NDP6020P field-effect transistors. They switch power electronically to the -servo and the fingerprint sensor, the two most power-hungry parts of the -circuit. The two MP1584EN buck converters play an axial role in efficiently -regulating power to the MCU and the sensor.

- -

The ATmega328P typically operates at 5V with a 16MHz crystal oscillator. To -further reduce power consumption, I modified the ATmega328P’s fuses to run at -3.3V with an 8MHz crystal oscillator.

- -

The bottom right area of the PCB isolates the power supply of the servo from -the rest of the circuit. This shields components such as the MCU from the -servo’s high current draw, which can exceed 1A. The IN4007 diode in slot U2 -serves as a flyback diode, protecting the MOSFET from reverse currents -generated by the servo.

- -

Lastly, the 56kΩ and 10kΩ resistors in slots R10 and R11 form a voltage divider -circuit. Its output is fed to the ADC of the MCU, which measures the supply -voltage by comparing it to the internal bandgap reference voltage.

- -

Epilogue

- -

This project began nearly a year ago when I attempted to unlock our door -wirelessly by writing to the UART ports of two MCUs connected to inexpensive -433MHz RF transceivers. Although I failed, it led me down a rabbit hole of RF -communications, MOSFETs, PCB design, and low-power circuits.

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During the project, I reinvented the wheel many times. I implemented a -low-level network stack using only RF modules and an 8-bit microcontroller, -designed my first PCB, and developed drivers from scratch. The project was far -from a smooth sail. Bad electrical connections, soldering, desoldering, and the -heartache of purchasing the wrong parts were routine. It was a long but -rewarding journey from the messy breadboard to the shiny PCB.

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Files: source.tar.gz, gerber.zip

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by W. D. Sadeep Madurange

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© ASCIIMX - 2025

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Projects

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- - - Experimental e-reader -
Experimental e-reader
- - 		- - - The Matrix digital rain -
The Matrix digital rain
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- - - Etlas: e-paper dashboard -
Etlas: e-paper dashboard
- - 		- - - Bumblebee: browser automation -
Bumblebee: browser automation
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- - - My first PCB -
My first PCB
- - 		- - - Fingerprint door lock -
Fingerprint door lock
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© ASCIIMX - 2025

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- - - - diff --git a/_site/projects/matrix-digital-rain/index.html b/_site/projects/matrix-digital-rain/index.html deleted file mode 100644 index 5218c10..0000000 --- a/_site/projects/matrix-digital-rain/index.html +++ /dev/null @@ -1,148 +0,0 @@ - - - - - The Matrix digital rain - - - - - The Matrix digital rain - - - - - - - - - - - - - -
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THE MATRIX DIGITAL RAIN

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12 JANUARY 2024
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“All I see is blonde, brunette, red head.” The iconic digital rain from The -Matrix in C, with zero dependencies—not even ncurses.

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Overview

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This is my fork of Domsson’s beautiful Fakesteak. While going through his code, I -wondered what it would take to faithfully recreate the original Matrix from the -first movie without sacrificing its minimalism.

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My implementation supports:

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  • Unicode characters.
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  • 24-bit RGB colors (truecolor).
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  • Glitches in the matrix.
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  • Ghosting effect of old monochrome CRT displays.
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  • Closely resembles the Matrix seen in the background during Neo and Cypher’s -conversation.
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With no dependencies, compilation is trivial:

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$ cc -O3 main.c -o matrix
-$ ./matrix
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How does it work?

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The program tracks the state of the terminal, such as code points, background -and foreground colors, and cursor position, using multiple internal data -buffers. On each frame, it updates these buffers and repaints the screen using -ANSI escape codes:

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static void term_print(const matrix *mat, size_t row, size_t col)
-{
-    size_t idx;
-    idx = mat_idx(mat, row, col);
-    wprintf(L"\x1b[%d;%dH\x1b[38;2;%d;%d;%dm%lc",
-        row, col,
-        mat->rgb[idx].color[R],
-        mat->rgb[idx].color[G],
-        mat->rgb[idx].color[B],
-        mat->code[idx]);
-}
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The ghosting effect is achieved by carefully scaling the RGB -channels before mixing them:

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static void mat_shade(matrix *mat, size_t row, size_t col) 
-{
-    unsigned char *color;
-    color = mat->rgb[mat_idx(mat, row, col)].color;
-    color[R] = color[R] - (color[R] - COLOR_BG_RED) / 2;
-    color[G] = color[G] - (color[G] - COLOR_BG_GRN) / 2;
-    color[B] = color[B] - (color[B] - COLOR_BG_BLU) / 2;
-}
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The ghosting function emulates the dim after glow by gradually transitioning -each raindrop’s color towards the background color. This approach provides two -key benefits: straightforward color configuration that integrates naturally -with (Unix) ricing and high-fidelity recreation of the Matrix aesthetic.

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Customization

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While you can alter almost every aspect, including speed, glitch frequency, and -rain density, the most common customizations are the color scheme and character -set.

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There are three color settings: head, tail, and background. You can configure -them using COLOR_*_RED, COLOR_*_GRN, and COLOR_*_BLU definitions found in -main.c.

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The UNICODE_MIN and UNICODE_MAX values control the Unicode block used. For -example, setting them to 0x30A1 and 0x30F6 rains Katakana, if a font that -supports Katakana is present on the system:

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Files: source.tar.gz

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by W. D. Sadeep Madurange

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© ASCIIMX - 2025

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MY FIRST PCB

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14 JULY 2025
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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.

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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.

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- Design (front) -

Footprint (front)

- 		- PCB (front) -

PCB (front)

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- Design (back) -

Footprint (back)

- 		- PCB (back) -

PCB (back)

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The PCBs have two layers. A copper region serves as the ground plane. The 0.3mm -wide 1oz/ft2 copper traces can carry up to 500mA (the tracks -connecting the power source and the linear regulators have a width of 0.5mm). -Both subsystems were functional. I was able to control the servo reliably using -the fingerprint sensor.

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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 13.8mA (3.3V) and 4.6mA -(5V) respectively, as long as they are connected to the power supply.

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Although the circuit didn’t draw more than 200mA without a load, the servo -under load could draw up to 600mA. I’m sailing too close to the wind with 0.3mm -copper traces. Instead, 0.4mm wide 2oz/ft2 traces would have been -safer.

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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.

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Files: gerber_back.zip, gerber_front.zip, - source.tar.gz

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by W. D. Sadeep Madurange

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© ASCIIMX - 2025

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