Homebrew LED Strips That Are HomeKit-Compatible

October 3, 2022 by Lewin Day 6 Comments

Google, Amazon and Apple are all duking it out for supremacy in the smart home space. As you’ve probably noticed, cheaper smart lights and the like typically don’t offer connectivity with Apple’s HomeKit system. However, if you want some smart lighting that works in that ecosystem without breaking the bank, you can always build your own!

This simple build uses an ESP8266-01S as the brains of the operation. It’s a cut-down board that only has two GPIO pins available, but for this job, that’s enough. It’s paired with a simple relay for switching a single-color LED strip on and off, and an MP2307 buck converter for power. The code loaded onto the ESP8266 is simple, and allows it to connect to Wi-Fi and link up with Apple HomeKit for control.

Let’s say you’re a real fancy-pants, though, and you want RGB-addressable LEDs for your HomeKit setup. No problem, you can do that too! It’s as straightforward as hooking up an ESP8266 to some WS2812B LED strip and flashing the right firmware that emulates an Elgato EVE LED strip. You can even activate special lighting effects on the via the EVE app if you so desire, to take advantage of the fully-addressable nature of the strip.

There are plenty of off-the-shelf solutions in this space, but many of them are quite expensive for what you actually get in the box. Sometimes building your own is more fun, too. Alternatively, if you don’t like Apple’s smart home solutions, you can always try a more open alternative. Video after the break.

Continue reading “Homebrew LED Strips That Are HomeKit-Compatible” →

Building A Poketch Powered By An Apple Watch

October 2, 2022 by Lewin Day 2 Comments

In Pokemon Diamond and Pearl and the ensuing modern re-releases, the player is given a computer called a Poketch to assist on their journey. [DistressedOwl] decided to build one for real.

The build starts with an Apple Watch, which provides a capable smartwatch platform and a quality display. It’s then given a snap-on case that’s 3D printed in PLA. [DistressedOwl] decided to use model painting techniques to give the build a worn-in, distressed look, which feels fitting for a watch belonging to a rough-and-tumble Pokemon trainer.

The Apple Watch runs a custom app via Test Flight which mimics the appearance of the in-game Poketch. It includes various screens like a basic map and Pikachu looking melancholy next to a digital watch. Sadly, the dowsing app in the Poketch won’t help you find hidden items on the ground.

It’s a build that reminds us of some great Pip-Boy builds over the years. It would make the perfect addition to a Pokemon cosplay, too. Just don’t forget to take some Pokeballs along too!

Teensy Becomes Tiny Handheld Computer, Plays Emulators

September 29, 2022 by Lewin Day 13 Comments

Science fiction predicted that we would one day all carry around tiny computers of great power. While smartphones are great, those predictions were more based on cuter systems that more closely approximated existing computers, with keyboards and screens. [Jean-Marc Harvengt] has built something along those very lines, and it’s called the T-COMPUTER.

This build centers around the mighty Teensy 4.1. That means it’s got an 800 MHz Cortex-M7 processor, 1 MB of RAM, and 8 MB of flash – eclipsing the specs of many retrocomputers of yesteryear. [Jean-MarcHarvengt] has paired the Teensy with a 42-key keyboard and a TFT screen, making a compact handheld computer platform. It’s also got VGA out for display on a bigger screen, along with USB and an old-school Atari joystick port! Power is via a small rechargeable lithium cell on the back, and 16-bit stereo audio is available via a standard 3.5mm jack. There’s also a little GPIO available if you need to interface with something.

It’s capable of emulating the Commodore 64 and Super Nintendo, as well as more obscure systems like the Atari Lynx. And before you ask – yes, it can run DOOM. It’s a fun little platform that would be enjoyable for retrogaming and hacking on the go. If you want to build your own, files are readily available on Github to recreate the system.

Handheld computer builds are always growing in popularity now that so much computing power can be had in a tiny devboard formats. If you’ve built your own neat little rig, be sure to let us know! Video after the break.

Continue reading “Teensy Becomes Tiny Handheld Computer, Plays Emulators” →

The 1337 PNG Hashquine

September 28, 2022 by Jonathan Bennett 7 Comments

A hashquine is a fun way to show off your crypto-tricks — It’s a file that contains its own hash. In some file types it’s trivial, you just pick the hash to hit, and then put random data in a comment or other invisible field till you get a collision. A Python script that prints its own hash would be easy. But not every file type is so easy. Take PNG for instance. these files are split into chunks of data, and each chunk is both CRC-32 and adler32 checksummed. Make one change, and everything changes, in three places at once. Good luck finding that collision. So how exactly did [David Buchanan] generate that beautiful PNG, which does in fact md5sum to the value in the image? Very cleverly.

Thankfully [David] shared some of his tricks, and they’re pretty neat. The technique he details is a meet-in-the-middle hack, where 36 pairs of MD5 collision blocks are found, with the understanding that these 36 blocks will get added to the file. For each block, either A or B of the pair will get plugged in at that location, and the md5sum won’t change. It’s a total of 2^36 possible combinations of these blocks, which is more computation than was practical for this particular hack. The solution is to pre-compute the results of every possible combination of the first 18 blocks, and store the results in a lookup table. The second half of the collisions are run backwards from a target CRC value, and the result checked against the lookup table. Find a hit, and you just found a series of blocks that matches both your target md5sum and CRC32 results.

Thanks to [Julian] for the tip! And as he described it, this hack is one that gets more impressive the more you think about it. Enjoy!

Empty Spools Make Useful Tools, Like Counters

September 25, 2022 by Kristina Panos 2 Comments

What’s the deal with getting things done? There’s a Seinfeld anecdote that boils down to this: get a calendar, do a thing, and make a big X on each day that you do the thing. Pretty soon, you’ll thirst for chains of Xs, then you’ll want to black out the month. It’s solid advice.

[3D Printy] likes streaks as well, and made several resolutions at the beginning of 2022. As the first of 30 videos to be made throughout the year, they featured this giant 3D printed counting mechanism (video, embedded below) that uses empty filament spools, some 3D prints, and not much else. These are all Hatchbox spools, and it won’t work for every type, but the design should scale up and down to fit other flavors.

This isn’t [3D Printy]’s first counter rodeo — he’s made several more normal-sized ones and perfected a clever carryover mechanism in the process, which is of course open-source. So each spool represents a single digit, and there are printed parts in the core that make the count carry over to the next spool. Whereas the early counters used threaded rod, this giant version rides on 2.5 mm smooth rod, so the spools can slide apart easily. But how does everything stay together? A giant elastic band made of TPU filament, of course — because the answer is always in the room.

Check out the video after the break, and stay for the 900%-sped-up assembly at the end.

Continue reading “Empty Spools Make Useful Tools, Like Counters” →

Wireless Water Detector Hooks Up To Home Assistant

September 22, 2022 by Lewin Day 19 Comments

Water damage can quickly make even the nicest buildings unliveable. [Andres Leon] suffered a small flood from an air conditioning unit, and wanted to avoid such issues in future. Thus, he built a wireless monitor to solve the problem.

The device is based on the ESP8266, allowing it to wirelessly communicate with Home Assistant. Thus, if it detects water via its rust-proof probes, it can notify Home Assistant via an MQTT message. From there, Home Assistant can advise the home owner remotely via phone and email. Plus, just for completeness, there’s a loud buzzer in the unit that goes off when water is detected, too. Thanks to a 2500 mAh lithium-polymer battery on board, the device can run for up to 5 months between recharges.

Integrating warning systems into one’s smart home system can be particularly useful when one is away for long periods. Things like water leaks tend to do damage over time when we’re not paying attention, so any IoT device that can assist in this regard is helpful. If you want to investigate the cause of a difficult leak, though, this other project may help. Video after the break.

Continue reading “Wireless Water Detector Hooks Up To Home Assistant” →

3D Print Yourself A Tiny Steam Train Complete With Smoke Effects

September 21, 2022 by Lewin Day 10 Comments

Model trains are fun, but sometimes little whirring motors in electric models feel a long way from the hulking metal beasts of the real railways. [Lewis] of [DIY Machines] adds back some of the flavor with this little steam train build, smoke effects included!

The body of the train itself is 3D printed in PLA. It’s designed to O-gauge scale, and comes complete with models for 3D printed track as well. The parts are given a coat of paint to better approximate the finish of the real thing; sometimes bare plastic just won’t suffice, after all.

Propulsion is thanks to an onboard battery and a simple gearmotor, driven by a HG7881 motor driver. An ESP32-CAM is responsible for running the show, allowing the train to be commanded wirelessly. As a bonus, the camera is mounted in the very front of the train, allowing one to watch a livestream of its progress about the tracks. Meanwhile, the smoke effect is thanks to a small water atomizer fitted in the train’s chimney, which makes the train look that little bit more authentic.

The combination of a self-powered train and 3D-printed tracks is a compelling one. [Lewis] has been able to leave his PETG 3D-printed track outside for over two years and it’s still in working order. That’s not something easy to achieve when using metal rails to deliver power.

Overall, this is a fun way to get into building your own model trains, and is a lot more hands-on than simply buying pre-built models from a store. From there, the sky is really the limit for your creativity! Video after the break.

Continue reading “3D Print Yourself A Tiny Steam Train Complete With Smoke Effects” →