Author: Zoe Skyforest

3645 Articles

Big 3D Printed BMO Is Also An OctoPrint Server

September 23, 2022 by 7 Comments

OctoPrint is a useful tool for 3D printers, providing remote access to essentially every 3D printer with a USB port. [Allie Katz] decided to build an OctoPrint server in the shape of a life-sized BMO from Adventure Time, and the results are cute as heck.

A Raspberry Pi 4 is the heart of the build, with [Allie] selecting a 8 GB model for the job. It’s paired with a Raspberry Pi touchscreen that serves as BMO’s face. The Pi is also given a stereo audio output board, and hooked up to a custom PCB that runs all of BMO’s buttons. Printing BMO itself was fairly straightforward, but requires some experience working with larger PETG parts. A useful note for those playing along at home is that Polymaker PolyLite PETG in teal is just about a perfect dupe for BMO’s authentic body color.

A bit of Python code animates BMO’s face and delivers funny quips at the press of a button. When it’s time to work, though, the touchscreen serves as a straightforward interface for OctoPrint. The resulting build is both fun and functional, and a great example of what 3D printing really can achieve. It’s a cute figurine and a functional print all in one, something we don’t see everyday!

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Robots Chase Down Balls In Fun Outdoor Game

September 22, 2022 by 1 Comment

Art installations aren’t always about static sculpture or pure aesthetics. In the case of Operation Kiba, they can be fun games for everyone to enjoy.

The aim of Operation Kiba is for the players to collect all the “balls” on the playing field, which are intended to represent scoops of ice cream. Collecting the balls is done via robot. Each player is ostensibly tasked with collecting one color of ball or the other, but players often decide to work together in harmony instead. The balls are released at the start of the game by tipping over a big bowl. This is half the fun, and is achieved by tugging a string which upends the vessel and scatters the balls.

The remote-control robots themselves come from an earlier art installation the group built called Bubble Blast. They’re built using a 3D printed chassis, with wheels on each side driven by DC gear motors. With tank-style steering, they can rotate on the spot, providing good maneuverability. An Arduino Nano runs the show, receiving commands over a 433 MHz radio link. Power is via DeWalt cordless drill batteries, and the robots are controlled via arcade sticks. They’re color-coded to match the balls in the game.

As far as art installations go, it may not be fancy or pretentious, but it certainly looks like a lot of fun. We’re sure it could eventually guide many players towards the exciting world of antweight combat robotics. Video after the break.

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Wireless Water Detector Hooks Up To Home Assistant

September 22, 2022 by 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.

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

September 21, 2022 by 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.

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Trojans Can Lurk Inside AVR Bootloaders

September 21, 2022 by 52 Comments

If there’s one thing we’ve learned over the years, it’s that if it’s got a silicon chip inside, it could be carrying a virus. Research by one group focused on hiding a trojan inside an AVR Arduino bootloader, proving even our little hobbyist microcontrollers aren’t safe.

The specific aim of the research was to hide a trojan inside the bootloader of an AVR chip itself. This would allow the trojan to remain present on something like a 3D printer even if the main firmware itself was reinstalled. The trojan would still be able to have an effect on the printer’s performance from its dastardly hiding place, but would be more difficult to notice and remove.

The target of the work was the ATmega328P, commonly used in 3D printers, in particular those using the Marlin firmware. For the full technical details, you can dive in and read the research paper for yourself. In basic terms, though, the modified bootloader was able to use the chip’s IVSEL register to allow bootloader execution after boot via interrupt. When an interrupt is called, execution passes to the trojan-infected bootloader’s special code, before then returning to the program’s own interrupt to avoid raising suspicion. The trojan can also execute after the program’s interrupt code too, increasing the flexibility of the attack. Continue reading “Trojans Can Lurk Inside AVR Bootloaders” →

Old Barcode Scanner Motherboards Live Again

September 21, 2022 by 1 Comment

Sometimes, hacking is just for the pleasure of diving into the secrets of old hardware. That was very much the case when [glitch] and a friend started hacking on some old Intel 8080 boards that had been living in the junk pile for too long.

The boards in question were motherboards from Identicon barcode scanners, running the Intel 8080 CPU. Hacking on the 8080 is a little different, with the ancient CPU requiring three separate voltages to run. However, with the power rails figured out and power applied, it was possible to get the old boards up and running.

The boards were first run with test ROMs which showed the 8080 CPU to be functional. The ROMs hosted a simple program which got the 8080 to spit out the word “HELO” on to an HP HDSP-2416 ASCII character display. From there, the barcode scanner boards were installed in a chassis and hooked up to a bigger Siemens character display, and the memory was mapped out.

The result was that [glitch] and co were able to largely reverse engineer the Identicon hardware, learning it was fairly similar to the Intel MCS-80 reference design of the era. They were able to get code running on the platform, access the RAM, and fit a larger 8-character display. However, without the original barcode scanner attachment, the boards weren’t able to return to their original duty.

As far as hacks go, it’s pretty old school. The boards don’t talk to Twitter, nor run the lights or help with the dishes. However, plenty of fun was had seeing if this old metal could be made to follow instructions once more. Hacking for the pleasure of it is always a good thing by our book!

A 3D Printed Marble Run Features Neat Elevator Linkage

September 21, 2022 by 20 Comments

There’s seldom anything as joyful and relaxing to watch as a simple marble run. Of course, the thing about letting marbles fall under gravity is that you eventually need to lift them back up again. The Marblevator has a mechanism that does just that.

Overall, the build features a relatively simple marble run. It consists of just six 3D printed ramps which the marble tumbles down in just a few seconds. However, the real magic is in the mechanism that restores the marbles from the bottom of the run all the way back to the top.

A motor turns a gear, which then rotates a crank leading to a multi-link rhombus. On one corner of the rhombus is a small protrusion with a magnet attached, which picks up the marbles from the bottom of the run. As the mechanism turns, the rhombus shifts and brings the marble-carrying arm to the top of the marble run. There, it’s grabbed by another magnet, which holds the marble for a moment before letting it drop back down through the run.

It’s a simple project that nonetheless would make a brilliant desk toy. It’s also a great way to learn about linkage analysis and designing such systems on your own. If you’re big into marble runs, you might also consider procedurally generating them. Video after the break.

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