05 | November | 2022 – Hackaday | Episode Movies

Water is sometimes referred to as the universal solvent. But researchers at Harvard want to use water to put things together instead of taking them apart. Really little things. In the video below you can see a simple 3D printed machine that braids microscopic fibers.

The key seems to be surface tension and capillary action. A capillary machine uses channels that repel floating objects. Moving the canal moves materials to avoid the canal, and shaping the canal allows various manipulations to occur, including braiding. This is one of those things that is easier to understand once you see it. So if it doesn’t make sense, watch the video below. The example uses tiny Kevlar fibers.

Continue reading “Nanoassembly with water”

"The Great Resistance" Color Code Lighting Project

As surface mount components are quickly becoming the norm for even DIY hardware, the resistor color code can feel a little dated at times. Anyone who’s ever tried to identify a random through hole resistor from a stack of different values ​​will know that having it up your sleeve is still a handy skill. With this attitude [j] decided to oversize the color code with “The Great Resistor”.

Resistor color code from Wikipedia with white background
How the resistor color code bands work

The heart of the project is an Arduino Nano clone and a potential divider that measures the resistance of the test resistor against a known fixed value. Using the 16-bit ADC, the theoretical range of measurable values ​​is 0Ω to 15MΩ, but there are some remaining electrical noise issues that currently limit the practical range to 100Ω and 2MΩ.

[j] measures the supply voltage to counteract the noise, but intends to move to an oversampling/averaging method to improve the results in the next iteration.

The measured value is shown on the front OLED display and in resistor color code on a giant symbolic resistor illuminated by WS2812 RGB LEDs behind.

Inside view of the large resistor with WS2812 LEDs and baffle plates
Inside the Great Resistor, the LEDs and baffle plates ensure the magic works

Precision aside, the project looks very impressive and we like the way the huge resistor has been constructed. It would look great at a science show or demonstration. We are sure that the noise issues can be fixed and we would encourage any reader with experience in this area to offer something [j] some tips in the comments below. There’s a video after the break putting The Great Resistor through its paces!

If you’re interested in learning more about the history of resistor color code tapes, you’ve come to the right place. Alternatively, how about reading the color code directly with computer vision?

Continue reading “The large resistance represents the smallest value”

Supercon is in full swing after a full day of badge hacking that lasted well into the midnight hour. Now is the time for the talks!

If you’re not here in person, you can still join the conversations by following the 2022 Hackaday Supercon Livestream, which covers all of the LACM stage action. We have a great series of speakers starting with a keynote from Joe [Kingpin] Grand at 10:00 am PDT and concludes with the 2022 Hackaday Prize Awards at 7:00 pm – see who won live!

Conversations are of course only one part of Supercon. The secret ingredient has always been the people at the con. If you’re not with us, we still need you. There is a conference chat on Hackaday.io and on the Hackaday Discord Server and everyone is welcome. Come and visit the folks at the con and others around the world who wish they had made it in person.

Make sure to catch the live stream on Saturday night to watch the grand prize being presented on stage during the Hackaday awards ceremony. Join the chat and ask for updates on badge hacking, the SMD soldering challenge, and all the other gimmicks that make Supercon so great.

We’re used to seeing all types of seven segment displays, be they mechanical, electronic or anything in between. But what all these displays have in common is that they are displays. Using them as inputs would just be crazy talk, right?

Maybe, but we like where [Dave Ehnebuske] goes with “InSlide”, the seven-segment input device. The idea for this comes from the “DigiTag” display that we introduced back in October, which divides a standard seven-segment character into three vertical stripes – two narrow ones for the outer vertical segments and one wide stripe that holds the horizontal elements. By moving these strips up and down relative to each other, the nine standard digits plus a few other characters can be assembled.

[Dave]s approach to this topic started with building his display out of laser cut pieces of plywood, which is a good choice due to the good contrast between the white wood and the engraved segments. Next, he embedded rare-earth magnets in the slides and installed seven Hall-effect sensors in the frame. The sensors are connected to an Arduino Nano via a 74HC165 parallel load shift register, allowing multiple modules to be connected in series. He also built an Arduino library to read the current state of the segments; It supports the full hexadecimal character set, or even duodecimal if you want.

[Dave] shared the library and it looks like you can get the build files for the mechanism from the original project. That’s good because this looks ripe for hacking. It looks like it would be fairly easy to motorize a display like this by adding rack and pinion gears and steppers – something like this could make an interesting watch.

[Scott Prints] had a known issue. His garage door opener was boring and rattled around annoyingly in the center console of his car. This was obviously a big problem that needed to be addressed. His solution was to install an ejection seat. Um, well, an ejection seat button. At least that’s what it’s labeled. (That’s sure to be a great conversation starter for passengers.)

The end result looks sleek and combines multiple building techniques. He began by measuring and 3D printing a test piece for the corner of the center console. Turns out that’s a more complicated shape than it seems. Instead of trying to measure the exact angles and radii, Scott turned to the tried and tested method of messing around with the parameters and printing a second test. Near enough.

The coolest and most challenging element of the build was engraving and cutting the aluminum plate that forms the visible part of the build. Turns out the online recommendations for milling aluminum are ridiculously optimistic if you don’t have an industrial CNC machine. Slower, shallower cuts got the job done, albeit slowly. A marker filled with red paint popped the letters. The guts of the dispenser garage door opener are fitted into a 3D printed shell, and then a large red knob is threaded into the print, holding the whole build together. A bit of soldering later, and the project is done. Simple, effective and very stylish! We agree. After the break, come back for the construction video.
Continue reading “Garage Door Opener Ejection Seat”

The advent of the high-end version of the Raspberry Pi camera has provided experimenters with a high-quality camera system that allows them to create better devices than mere snapshot cameras. It has been used by experimenters for some exciting projects, but so far very few have broken away from the Pi Camera’s C-mount lens system. [Tom Schucker]’s Pieca is an interesting departure then, because it takes the Pi HQ camera into new territory by using Leica rangefinder lenses.

There are enough Pi Camera projects out there where the setup process should be pretty familiar by now. This one is slightly different using a focal reducer mounted in a 3D printed Leica lens mounting plate. The result is that the Leica lens is better matched to the much smaller size of the Pi camera sensor compared to a 35mm frame.

The camera’s aesthetic design is rather chunky, likely due to the choice of a Pi 4 over a Pi Zero. However, it remains very usable and produces photos with a distinctive feel. You can see more in the video under the break. In the meantime, if you’re not lucky enough to own a whole stash of Leica lenses, maybe you could consider adapting more common optics? We’ve seen it before with the original Pi Camera.

Continue reading “Pieca is a Pi camera with some very nice lenses”

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