Author: John Baichtal

208 Articles

Hackaday Prize Entry: Gaming Done Tiny With Keymu

June 30, 2017 by 23 Comments

The world’s tiniest Game Boy Color, introduced at the 2016 Hackaday SuperConference, is a work of art. This microscopic game console inspired [c.invent] to create how own gaming handheld. His Keymu project on hackaday.io describes an open source, keychain-sized gaming handheld that its builder claims is really the world’s tiniest. How did he make it smaller? It’s a miniature Game Boy Advance SP, and it folds up in a handy clamshell case.

While he’s a Pi fan, [c.invent] felt the Pi Zero was too big and clunky for what he had in mind–a keychain-sized handheld. Only the Intel Edison was compact enough. He began with a custom PCB with a connector for the Edison’s fragile ribbon cable, then added an 1.5″ OLED display and an 11.7mm speaker, all powered by a 220 mAh lithium battery. [c.invent] also created inside a custom folding 3D-printed case that protects the Keymu’s electronics from keys and pocket lint.

Unlike the mini Game Boy Color, [c.invent] aims to create a fully fledged emulation console. The Edison incorporates a Linux distribution that allowing it to install emulators for GameBoy Color, GBA, NES, and SNES.

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Making Spirographs With LEGO And Math

June 29, 2017 by 11 Comments

Master LEGO builder [Yoshihito Isogawa] has been on a roll lately, cranking out a number of robots that make drawings reminiscent of the classic Spirograph toy. For instance, he built an elegant drawbot out of LEGO elements, seen above. At first glance the monicker “spirograph” seems wrong, because where are the gears? However, [Yoshihito] has them stashed underneath the sheet of paper, with magnets controlling the pens.

His drawbot consists of a platform (cleverly, an inverted LEGO plate) upon which a sheet of paper is laid. One or two pen holders, each with a pair of magnets underneath, rest on the sheet of paper. Beneath the plate, two pairs of spinning magnets rotate around a double layer of 11×11 curved racks, which then play the role of the classic spirograph rings. An EV3-controlled motor powers the whole thing.

He also makes use of an obscure part–the 14-tooth bevel gear, last manufactured by LEGO in 2002 and even then it was mostly sold in part assortments intended for the education market. It’s so obscure LEGO doesn’t even provide the gear in their online building program LEGO Digital Designer, though (of course) the LDraw folks re-created it — it’s brick 4143 in the library, seen below.

Spirograph Gear Math

This gear becomes important in spirograph-style projects because tooth count is everything. There really aren’t that many spirograph designs that can be made with LEGO, because there are a limited number of gears and they mostly have the same tooth counts–the smaller ones sport 8, 12, or 16 teeth, medium-sized ones 20 or 24 teeth, and larger ones 36 or 40 — see a pattern? Such predictability may be great for a building set, but it doesn’t engender a lot of spirograph diversity.

When you compute the number of vertices in a spirograph shape, you take the least common multiple of the two gears (or sets of gears) and divide by the small gear. So a 60-tooth turntable turning a pair of 14-tooth gears has an LCM of 420, and you divide by 28 to get the number of vertices: 15. Remove one of those smaller gears and the vertices increase to 30. The challenge in creating new shapes with a LEGO spirograph lays in swapping in new gears, just like the original toy, and having more ways to come up with unusual gear ratios makes for more interesting drawings.

Another that makes the 14-tooth gear so alluring to [Yoshihito] is that it’s one of the few LEGO gears with a number of teeth not divisible by 4. Among other things this means the gear meshes with an identical gear at 90 degrees. Usually the gears have the same number for each quarter of the circumference and meshing becomes a matter of jogging one gear a scosh. This can be a problem because LEGO axles have a “plus” shaped profile, and you may not want everything on that axle tilted as well — having a 90-degree solution makes a lot of sense.

[Yoshihito] designs LEGO robots out of Isogawa Studio and has written several books on advanced LEGO techniques, published by No Starch. He specializes in small and elegant mechanisms — finding the perfect set of elements that work together effortlessly. You can see an example in the gear assembly to the right — a pair of the aforementioned 14-tooth bevel gears, turned into a normal gear with the help of that golden spacer, none other than a One Ring from LEGO’s Lord of the Rings product line. You can find videos of his projects on YouTube.

[Yoshihito] has released a number of variants of the spirographing drawbot. What’s next? Maybe a harmonograph?

Continue reading “Making Spirographs With LEGO And Math” →

Ambitious Hackerboat Project Still Aiming High

June 28, 2017 by 7 Comments

Last year we wrote about Hackerbot Labs’ autonomous boat, which project members hope to someday circumnavigate the globe. Now called Project Ladon, progress continues apace with a recent ocean test of their modified 18’ kayak, the TSV Disputed Right of Way. The kayak’s internal spaces contain a pair of lead-acid truck batteries controlled by a home-brewed control system that uses relays to control the craft’s trolling motor, with a Beaglebone and Arduino Mega under the hood.

The test was not exactly a success, with the boat actually avoiding the waypoints rather than sticking to them. Fortunately the team was aboard a chase boat so they were able to keep tabs on the craft. Unlike a quadcopter, which just falls down, a watercraft that borks may never be seen again.

Entered into the 2016 Hackaday Prize, the project has continued to gather steam, with presentations at both Toorcamp and Maker Faire Bay Area. In addition, they’re maintaining their Hackaday.io project site as well as a Patreon page.

Check out a couple of videos after the break! The test video is 360-degrees so you can drag around the POV.

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Hackaday Prize Entry: A Tiva Shaped Like An Arduino

June 27, 2017 by 17 Comments

Texas Instruments’ Tiva C LaunchPad showcases TI’s ARM Cortex-M4F, a 32-bit, 80Mhz microcontroller based on the TM4C123GH6PM. The Tiva series of LaunchPads serve as TI’s equivalent of the Arduino Uno, and hovers at about the same price point, except with more processing power and a sane geometry for the GPIO pins.

The Tiva’s processor runs five times faster than standard ATMega328P, and it sports 40 multipurpose GPIO pins and multiple serial ports. Just like the Arduino has shields, the Tiva has Booster Packs, and TI offers a decent number of options—but nothing like the Arduino’s ecosystem.

[Jacob]’s Arduino-Tiva project, an entry in the Hackaday Prize, aims to reformat the Tiva by building a TM4C123GH6PM-based board using the same form 2″x 3″ factor as the Arduino, allowing the use of all those shields. Of course, an Arduino shield only uses two rows of pins, so [Jacob]’s board would position the spare pins at the end of the board and the shield would seat on the expected ones.

The finished project could be flashed by either the Arduino IDE or TI’s Energia platform, making it an easy next step for those who’ve already mastered Arduinos but are looking for more power.

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Tiniest Control Board Fits Inside An N-Gauge Model Train

June 27, 2017 by 18 Comments

[kodera2t] discovered the VL53L0X Time of Flight sensor and thought it would make a great way to control the operation of a model train without touching it. He explains it in his own words in the demo video.

The sensor was small enough for an N-gauge train, which translates to 1:148 scale or about 9mm from rail to rail. His idea was to build a tiny control board that could fit inside the locomotive: 10mm by 40mm. His board consists of the ToF sensor, an ATMega328P-MMH, USB-serial, and a Texas Instruments DRV8830 motor driver. he powers the board via the 6V running through the track.

Right now [kodera2t]’s using the ToF as sort of a gestural controller to get the train to start rolling, but one could imagine the sensor could be incorporated into more advanced programming, like having the train speed up on straightaways and slow down on a curve, based on the height of the bridge over it.

We’ve published a bunch of [kodera2t]’s tiny circuit board projects here on Hackaday, including the smallest basic computer, his minimal frequency counter, and his VFD amplifier.

Continue reading “Tiniest Control Board Fits Inside An N-Gauge Model Train” →

Ambitious ATtiny85 Board Tests A Beginner’s Skills

June 26, 2017 by 31 Comments

[Chris O’Riley] has been playing around with Arduinos for around a year, and decided he wanted a breadboardable ATtiny85 in order to prototype using the actual controller that would be used in the final project. He wants to use it to interface with a Bosch BMP280 pressure sensor, but for now it stands alone.

It’s a simple board with the Tiny85, 3.3 V and 5 V regulators, a power LED, as well as the usual resistors and caps [Ed: not resistor sand caps]. The double-sided PCB [Chris] milled himself — he’s an illustrator and photographer by day, so it’s no surprise the board turned out gorgeous. He designed the board in Illustrator after taking a stab at Eagle, then ran it through his CNC to mill the circuits using a .017 inch end mill as well as drilling the vias. He add solder paste using the tip of a knife, but after messing around with an iron, he ended up investing in a hot air rework station.

We love our Tiny85s here on Hackaday. Check out the ATtiny85 gaming console, the NTSC-generating ATTiny85, and making DIY I2C devices with the chip.