A personal blog and portfolio for Software & Computer Engineer Rory Hayes. https://rorosaurus.github.io/roryhay.es//roryhay.es/ Thu, 27 Aug 2026 20:58:35 +0000 Thu, 27 Aug 2026 20:58:35 +0000 Jekyll v3.10.0 Can you spot the difference between these two development boards? With my latest shipment of C3 Super Mini’s, I’m unable to connect to Wi-Fi about 95% of the time. When I can connect, I’m seeing 10-16 dBm less signal strength compared to previous shipments. That translates to a 2.5-4x worse overall Wi-Fi connection, which is effectively a death sentence for the already minimal, compact antenna design. I found this out after buying in bulk! 😳 Fortunately it was an AliExpress Choice purchase, so I’m able to submit a free refund. So what went wrong here? What can we learn about the importance of good RF design? And how can we avoid falling victim to sellers cost optimizing a product into oblivion? Investigating the fault Let's look closer and compare the working and faulty boards Differences I found on the faulty boards Can’t connect to Wi-Fi, but can host its own AP fairly reliably. Perhaps transmit performance is ok, but receive is poor? Unmarked LDO for 3.3V Tested with a 1000uF capacitor across 3.3V and GND and verified poor Wi-Fi was not due to this component PCB panelization via mouse bites instead of V-Cut I can’t imagine this affects anything, but... ]]> Sat, 29 Jun 2024 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/esp32-c3-super-mini-flaw https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/esp32-c3-super-mini-flaw Maker Soldering LEDs ESP32 WLED I’m always on the lookout for a new favorite microcontroller. The ESP family has been my favorite for quite some time now, and the new C3 chip offers quite a lot in a super cheap package! I assume that’s due to its RISC-V architecture reducing licensing costs for Espressif. What’s it got? This tiny board can be had for less than $2.50 and comes in at 18mm x 22.5mm - perfect for tiny projects! The C3 only has a single CPU core @ 160MHz, which is a downgrade from the 240MHz dual core LX6 CPU on the original ESP32. Connectivity-wise, the C3 still has 2.4 GHz Wi-Fi (802.11b/g/n) and Bluetooth® 5 (LE). This Super Mini dev board uses the optional 4 MB flash integrated in the C3’s tiny QFN32 (5×5 mm) package. Why’s it good for WLED? The USB-C connector and PCB traces are robust enough to handle 5V@3A continuously from my testing, so it’s an ideal little WLED driver for some small 5V LED projects. As usual, you can get away without a level shifter if your data line is short enough (less than a couple feet). The antenna component has better range than PCB trace antennas too! My... ]]> Fri, 20 Oct 2023 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/esp32-c3-super-mini https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/esp32-c3-super-mini Maker Soldering LEDs ESP32 WLED For my latest job hunt, I decided to do away with single-use business cards altogether! I just want to make one reusable, high-tech card and carry it with me! For about $2/card, you can DIY your own low volume, homemade smart business cards! Scan the card with any phone and my website will open, where you can collect my contact info and read about my projects! It’s classy, sanitary, and environmentally friendly! A quick demo of how easy it is! What to keep in mind when buying NFC cards Personally, I prefer my card to navigate directly to my website, where the user can choose whether download my virtual contact card. Alternatively, I could embed the contact card itself directly, but then the user would have to import/save/find the contact and navigate to my website from there! With just my website, they can just keep my tab open to read more about me later after the in-person exchange is over! For my project, I bought these NFC cards directly from AliExpress, but you can buy NFC cards from my vendors online! They also come in a variety of shapes/sizes if you don’t specifically want a business card. The two most... ]]> Sun, 01 Jan 2023 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/nfc-business-cards https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/nfc-business-cards Maker Laser NFC Web My friend got this “neon” LED fixture for Christmas! It looks excellent except it’s unfortunately blindingly bright for most situations! Not only is this not ideal for our eyes, it’ll run the LEDs hot and reduce the lifespan of the piece. Depending on how it works, dimming it could be as easy as simply adding a potentiometer across the +5V input. I had all the parts/tools within arms reach, so why not prototype and test it right now? If it takes less than five minutes to do, don’t leave it for later! Looking closely at the LED PCB, we can see these LEDs run on 5V. So the strips receive the +5 and GND directly from the USB port. That means the switch probably isn’t hiding any smart components, it’s just a switch! There are resistors across the LED strips to help even out the brightness, but they seem to have selected quite an aggressive amperage/brightness for the fixture as a whole. We could add a single resistor in series with the +5V wire to fix the amperage allowed to flow according to Ohm’s Law: Voltage(V) = Current(I) x Resistance(R) So in general, the more resistance we add, the smaller... ]]> Sun, 25 Dec 2022 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/5v-neon-led-dimmer https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/5v-neon-led-dimmer Maker Soldering LEDs I created a custom Flipper Zero firmware, forked from DarkFlippers/unleashed-firmware, which adds some custom animations and QoL fixes to the already endless potential granted by Unleashed! I’ll occasionally update this firmware to keep up with Unleashed releases. What’s so exciting about this nerdy Tamagotchi? When a thoughtful friend gifted me a Flipper, I was surprised and excited! Sometimes your friends know you better than you know yourself! 😅 Thank you Austin!! 💜 This tool is something I’ve always wanted to build myself (with a lesser scope), so it’s been thrilling to dive in and learn all about these security technologies and how they work. For example, when Alesha needed a friend to watch her cat, her apartment complex issued her a spare card key. Using my Flipper, I compared that key with her original to find that they issued a new identifier for this spare! Good security! Now if the spare is lost or copied, that identifier can be marked as untrusted without impacting Alesha’s main key. It’s a small detail but one that definitely builds confidence in where you live! Demonstrating RFID emulation of previously read RFID! I’m excited to keep learning and testing everything I can get my... ]]> Fri, 21 Oct 2022 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/furret-zero-unleashed https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/furret-zero-unleashed Furret Flipper NFC RFID Security Hardware This year I’ve started to learn DJing! So after seeing this DiWHY on reddit, the gears started turning in my head! I think it would be fun to give you an idea of how I approach a small microproject like this! Rory’s Internal Dialogue What would a Rory version of this look like? Well, we know it has to have individually addressable LEDs… 😅 … … ..yeah, that’s all I got. 😅 Okay, but how to power them? I suppose I could put a small battery in there, but it would be ideal if I can just siphon power from the USB-A port without affecting the flash memory. I’d just want to keep the power budget well under the 500mA we’d be guaranteed from a USB2.0 port. I’ll have to test everything before putting it together and ensure the flash memory has enough power for it’s hungriest operations still. But what microcontroller to use? It’d be nice to use an ESP32, my favorite, and wirelessly change and sync animations. Unfortunately ESP32’s are 3.3V and using the radio would cause power fluctuations, unless I also add a capacitor… No, it’d be better to go with a simple, low-power microcontroller. Hey! These... ]]> Thu, 14 Apr 2022 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/covid-usb https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/covid-usb LEDs Arduino Programming Maker This mod requires some case trimming, and I would recommend abandoning your charging dock contacts. More information available in the instructions page. The truly universal USB-C dream is finally realized for your Nintendo 3DS XL! Charge your Nintendo 3DS XL with USB-C, using any USB-C cable and charger! If it fits, it’ll charge! Finally you can stop carrying around that extra proprietary cable! My design is inspired by this existing PCB that only works with USB-A -> USB-C cables. In my opinion, if you’re gonna future-proof your 3DS XL, you shouldn’t remain reliant on Type-A! My PCB works with USB-C <-> USB-C cables as well, so you can use ANY USB-C cable/charger to charge it! I’ve also verified it works with USB-A -> USB-C cables, Quick Charge, and USB-PD! That means if your charger or USB battery pack offers 5V/9V/12V/etc., it will recognize the 3DS XL can only accept 5V and charge accordingly. No 3D-printed part is included, but the file is available for you to print yourself, if you want. Where to Buy USA: Buy on Amazon - (Why Amazon?) Any other Country: Buy on Tindie - (I will restock occasionally!) Compatibility This is designed for installation in any... ]]> Tue, 25 Aug 2020 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/3ds-xl-usb-c https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/3ds-xl-usb-c Hardware PCB Mods Gameboy USB-C The truly universal USB-C dream is finally realized for your Nintendo DS Lite! Charge your Nintendo DS Lite with USB-C, using any USB-C cable and charger! If it fits, it’ll charge! Finally you can stop carrying around that extra proprietary cable! My design is inspired by this existing PCB that only works with USB-A -> USB-C cables. In my opinion, if you’re gonna future-proof your DS, you shouldn’t remain reliant on Type-A! My PCB works with USB-C <-> USB-C cables as well, so you can use ANY USB-C cable/charger to charge it! I’ve also verified it works with USB-A -> USB-C cables, Quick Charge, and USB-PD! That means if your charger or USB battery pack offers 5V/9V/12V/etc., it will recognize the DS Lite can only accept 5V and charge accordingly. Where to Buy USA: Buy on Amazon - (Why Amazon?) Any other Country: Buy on Tindie - (I will restock occasionally!) Compatibility This is designed for installation in any Nintendo DS Lite (USG-001). This is not compatible with the original (fat) Nintendo DS, NTR-001. (My other mod for GBA-SP, does work in the NTR-001.) Charge Speed This console’s original charger (USG-002) outputs up to 450mA at 5.2V. According to the... ]]> Sun, 02 Aug 2020 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/nds-lite-usb-c https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/nds-lite-usb-c Hardware PCB Mods Gameboy USB-C The truly universal USB-C dream is finally realized for your Game Boy Advance SP! (Also compatible with the original Nintendo DS!) Charge your Game Boy Advance SP with USB-C, using any USB-C cable and charger! If it fits, it’ll charge! Finally you can stop carrying around that extra proprietary cable! My design is based off this existing PCB that only works with USB-A -> USB-C cables. In my opinion, if you’re gonna future-proof your Game Boy, you shouldn’t remain reliant on Type-A! My PCB works with USB-C <-> USB-C cables as well, so you can use ANY USB-C cable/charger to charge it! I’ve also verified it works with USB-A -> USB-C cables, Quick Charge, and USB-PD! That means if your charger or USB battery pack offers 5V/9V/12V/etc., it will recognize the Game Boy can only accept 5V and charge accordingly. Final result! This product was featured on the Tindie Blog! Source Code and Design Files on Github! Options To reduce confusion and simplify filling orders, I’ve consolidated the options into just one offering which satisfies 70% of orders. I go into a bit more detail here. I will assemble the components for you before shipping. You only have to desolder... ]]> Fri, 03 Jul 2020 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/gba-sp-usb-c https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/gba-sp-usb-c Hardware PCB Mods Gameboy USB-C Mon, 16 Dec 2019 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/usb-pd-trigger-manual https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/usb-pd-trigger-manual Hardware PCB Soldering USB-C I put this project together as the cheapest way to get into experimenting with HUB75-type LED panels, using my driver board for the ESP32! Youtube Demo, YouTube - Proof of concept WiFi controller Hardware (BOM) Project Mc2 LED Purse (Usually costs ~$6): Amazon, Adafruit article A cheap 16x32px LED display you can harvest. The deafult driver/app requires 3.5mm headphone jack and phone connected at all times, otherwise after 30 seconds your pattern will freeze, then turn off. You’re also limited to like 6 colors. So let’s make our own driver! If you want to daisy-chain from this display, it’s missing an output socket and ribbon cables: SMT 2x8 Male IDC Socket: AliExpress 16P IDC Cable (might have come with your panel): AliExpress PCB I designed to drive HUB75 panels with an ESP32: Buy on Tindie! This part is optional, but greatly simplifies your wiring! If you don’t want to use my PCB, you can wire the display yourself manually using dupont connectors following ESP32_FORUM_PINOUT from MatrixHardware_ESP32_V0.h ESP32-DEVKIT-V1: Amazon ($14 for 2) Total cost should be quite low for a 32x16 scantype LED panel with Wifi/BT, powered by micro-USB, capable of: playing gifs, scrolling text, and FastLED! Assembly Instructions Some assembly... ]]> Wed, 11 Dec 2019 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/project-mc2-led-purse https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/project-mc2-led-purse Hardware PCB Soldering ESP LEDs Wait but how? The LED panels are driven by an ESP32, controlled by a phone via Wifi! Yes, he’s built using “Arduino”! No, they aren’t normal “Neopixel” LEDs, they’re HUB75! Yes, he is adorable! The LED panels were $25 each and the microcontroller was $5. It’s powered by a normal USB battery pack! The original pixel art animation was done by the extremely talented Alex Illustration! We used Photoshop to modify the original animation and to make all the other animations! Where is Furret? Furret uses Meshtastic, a peer-to-peer LoRa mesh network, for long range (up to 10km!) reliable texting and GPS coordinate sharing! After getting your hardware (~$30) and setting up the device, join his channel and you can find Furret easily at festivals! We’ll try to announce future planned events on Instagram! Click here to join his channel, or scan the QR code below! Furret's Meshtastic Channel Special Thanks @alex_illustrat - who originally created the 8bit pixel art for Furret Walking. See more of his work on ArtStation! narpy - for starting the most adorable, wholesome, meme @pikachutotem - who inspired me to make Furret! Sprite_tm, Craig A. Lindley, Louis Beaudoin, and Marc Merlin - for the below... ]]> Wed, 09 Oct 2019 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/furret-totem https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/furret-totem Hardware PCB Soldering ESP LEDs Music Totem Drive HUB75 LED panels using an ESP32-DEVKIT-V1 and SmartMatrix library! Features Compatible with SmartMatrix and FastLED libraries! Play animated .gifs (from SPIFFS) on your LED panel using Marc Merlin’s AnimatedGIFs sketch! Animate scrolling text (and more!) using SmartMatrix’s FeatureDemo! ESP32 provides 2.4GHz Wifi/Bluetooth capability, and is Arduino compatible! The PCB connects all 16 pins needed to drive HUB75 panels using ESP32_FORUM_PINOUT from SmartMatrix library. Compatible with 1/8, 1/16, and 1/32 scan type HUB75 panels. Supports multiple HUB75 panels daisy-chained in series! (Verified working with 5 panels!) Two different ways to connect to your LED panel: Output Mode 0: directly plug this PCB into your LED panel using 2x8 female pin headers. Output Mode 1: connect this PCB to your LED panel via 16 pin IDC socket (ribbon cable not included). 3x5 = 15 pins broken out for additional use: 3x GND 3x 3.3V 9x GPIO pins (8 with ADC!): for buttons, potentiometers, sensors, etc.! Optional two screw terminals to manage 5V power flow between ESP32 and your LED panels. Optional pads for one through-hole Electrolytic Capacitor (I use 1000uF) to smooth the 5V power. Optional pads for one 1206 SMD Ceramic Capacitor (I use 10uF) to enable the automatic bootloader.... ]]> Mon, 07 Oct 2019 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/esp32-hub75-driver https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/esp32-hub75-driver Hardware PCB Soldering ESP LEDs Okay, here’s my quick soapbox on Silicone Conformal Coating! This is easily my favorite thing in my soldering toolbox! That shouldn’t be too much of a surprise, given its wide use in commercial PCB production - but it’s crazy useful for small hobbyist projects too! I use Silicone Conformal Coating on almost all of my projects, especially if they are intended for outdoor use where robustness is important! Electrically Insulating It’s electrically insulating! After careful application and letting it dry, your electronics can be effectively waterproof! Plus, you don’t need to worry about anything getting out of place and shorting out! I’ve seen this used to make drones fly underwater! Blacklight Reactive You can use UV light to identify where it’s been applied! It makes verification of application really easy! Plus it looks cool! Just avoid applying the coating to USB ports, other connectors, or buttons. Anything with mechanical moving parts, I suppose. I’d also avoid getting it on your hands! A Little Gluey Conformal coating gets a bit gooey/tacky while drying, so keep that in mind. This is usually very useful, since it can provide some mild relieve strain on solder joints and seal everything together snugly. I’d still... ]]> Mon, 05 Aug 2019 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/conformal-coating https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/conformal-coating Hardware PCB Soldering Let’s make a synchronized LED Goggle Squad using the ESP8266! This project contains code and instructions to build a squad of rechargable LED goggles that automatically synchronize their animations with each other! You can change the code parameters slightly to work with different LED strip types or lengths! Demonstrating syncing two separate devices! Right now, we have about 30 unqiue members of the squad. Most people have created goggles, but some have created backpacks, bike lights, a tall flagpole, massage table underglow, and more! They all sync together using the same ESP8266 board to create a mesh network (over wifi) and sync their animations! Make your own! Follow my assembly instructions to make your own Goggles/Backpack/Bike-pole/etc. and join our squad! How to use yours I added a wink button to greet new people! Check out this page for tips for using your Goggles! It’ll help explain what the buttons do. ]]> Tue, 21 Aug 2018 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/esp8266-goggle-squad https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/esp8266-goggle-squad ESP Programming Arduino Mesh LEDs Maker The first thing you see when you start your PocketSprite is the chooser. It’s main tasks are to allow you to upload/delete files (including apps) via WiFi Access Point and launch apps that are present on the filesystem. This is a modified version of the chooser.app, which greets you with a smiling BMO face and a short sound clip when you launch it (with wifi disabled). Who wants to play videogaaaames!? Even with a poor paint job, it’s instantly recognizable as BMO! Installing Download the latest version from GitHub Rename chooser.bin to chooser.app (GitHub won’t let me release a .app file) Follow the normal app installation instructions ]]> Thu, 05 Jul 2018 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/pocketsprite-bmo-chooser https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/pocketsprite-bmo-chooser Programming ESP Maker Gameboy August 2018 Update: This project is in its second iteration! Check out the mesh-network Goggle Squad, powered by the ESP8266! A few months ago I made some custom LED goggles to light myself up at events! I found they fit in well at concerts and festivals I attend! Since I keep getting questions about how to make them, I decided to throw together a post with some links and tips! Build overview Time investment: 3-8 hours Skills required: soldering, programming Cost: ~$40-60 The time investment is really dependent on your proficiency at the required skills and your tendency to be perfectionist with the wiring. :) Most of the parts I used are available in a single kit from Adafruit! The main modifications I made on top of this kit are: Added a 3 x AAA Battery Holder to the strap for extended battery life and easy on/off Added two push buttons which wire into PINs on the Trinket to control effects/settings How to make your own You should start by following this tutorial on Adafruit. It’s very detailed and gets us most of the way there! You’ll also need to complete the Introducing Trinket and All About Arduino Libraries tutorials.... ]]> Sun, 18 Dec 2016 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/neopixel-goggles https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/neopixel-goggles Programming Arduino LEDs Maker Fri, 22 Apr 2016 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/hidden-konami-js https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/hidden-konami-js Math Web One day I decided I want to discover a prime number of my very own. After a bit of research, and 203.53 quadrillion floating-point operations later, I became the proud father of: 5687 · 21376451 + 1 a 414,357 digit-long titanic Proth Prime! As of 1/29/2016 06:20:31 CDT, this is the 2,261st largest prime ever discovered! Raw decimal representation: rorys-prime-decimal.txt This Proth Prime Search was done in collaboration with the Proth Search project. This search looks for primes in the form of k · 2n + 1, with the condition 2n > k. These are often called Proth primes. Thanks to the PrimeGrid project and BOINC for making this pretty easy to get started! Additional links: Prime number list for participant “rorosaurus” Entry in The Largest Known Primes Database ]]> Sat, 30 Jan 2016 10:32:20 +0000 https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/prime https://rorosaurus.github.io/roryhay.es//roryhay.es/blog/prime Math Compute