Welcome To The Internet Of Hamsters

May 16, 2018 by 8 Comments

It was only a matter of time. Everything else is getting its data logged and reported to the Internet for detailed analysis, so why should our rodents be any different? The cover story is that [Nicole Horward] hooked her pet hamster Harold up to the web because she wanted to see if he was getting as much exercise as he should. The real reason is, of course, that Harold wanted to show off to his “friends” on Hamsterbook. (Editor’s note: dead link, but take a look at the Wayback Machine.)

The hardware side of this hack is very simple, a magnetic door sensor (like the kind used in alarm systems) is used to detect each time the wheel makes a complete rotation. The sensor is hooked up to the GPIO pins of a Raspberry Pi, where it’s read by a Python script. A small LCD screen was added to give some visual feedback on Harold’s daily activity, and the whole thing was boxed up in a laser cut enclosure.

That gave [Nicole] a cute little display next to Harold’s cage, but it didn’t do much for analyzing his activity. For that, a script is used to upload the data every minute to a ThingSpeak channel via MQTT. This automatically generates attractive graphs from the raw data, making it much easier to visualize what’s happening over the long term.

Now might be a good time to brush up on your MQTT knowledge, so that your pet could be the next to join the IoT revolution.

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3D Printering: When An STL File Is Not Quite Right

May 16, 2018 by 49 Comments

STL files are everywhere. When there’s something to 3D print, it’s probably going to be an STL. Which, as long as the model is good just as it is, is no trouble at all. But sooner or later there will be a model that isn’t quite right in some way and suddenly project progress hits a snag.

When models interface with other physical things, those other components may not always be exactly as the designer expected. Being mindful about such potential inconsistencies during the design phase can help prevent problems, but it’s not always avoidable. The reason it’s a problem is because an STL file represents a solid model as a finished unit; it is not really intended to be rolled back into CAD programs for additional design changes.

STL files can be edited, but just like re-modeling a component from scratch, it can be a tricky process for those who don’t live and breathe this stuff. I’ll describe a few common issues related to STLs that can hold up getting that new project together, along with ways to deal with them. Thanks to 3D printing becoming much more commonplace, basic tools are within reach of even the least CAD-aware among us.

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IKEA Lamp With Raspberry Pi As The Smartest Bulb In The House

May 16, 2018 by 27 Comments

We love to hack IKEA products, marvel at Raspberry Pi creations, and bask in the glow of video projection. [Nord Projects] combined these favorite things of ours into Lantern, a name as minimalist as the IKEA lamp it uses. But the result is nearly magic.

The key component in this build is a compact laser-illuminated video projector whose image is always in focus. Lantern’s primary user interface is moving the lamp around to switch between different channels of information projected on different surfaces. It would be a hassle if the user had to refocus after every move, but the focus-free laser projector eliminates that friction.

A user physically changing the lamp’s orientation is detected by Lantern’s software via an accelerometer. Certain channels project an information overlay on top of a real world object. Rather than expecting its human user to perform precise alignment, Lantern gets feedback from a Raspberry Pi camera to position the overlay.

Speaking of software, Lantern as presented by [Nord Projects] is a showcase project under Google’s Android Things umbrella that we’ve mentioned before. But there is nothing tying the hardware directly to Google. Since the project is open source with information on Hackster.io and GitHub, the choice is yours. Build one with Google as they did, or write your own software to tie into a different infrastructure (MQTT?), or a standalone unit with no connectivity at all.

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Gentle Electric Eel

May 16, 2018 by 22 Comments

It’s no shock that electric eels get a bad rap for being scary creatures. They are slithery fleshy water snakes who can call down lightning. Biologists and engineers at the University of California had something else in mind when they designed their electric eel. Instead of hunting fish, this one swims harmlessly alongside them.

Traditional remotely operated vehicles have relied on hard shells and spinning propellers. To marine life, this is noisy and unnatural. A silent swimmer doesn’t raise any eyebrows, not that fish have eyebrows. The most innovative feature is the artificial muscles, and although the details are scarce, they seem to use a medium on the inside to conduct a charge, and on the outside, the saltwater environment conducts an opposite charge which causes a contraction in the membrane between to the inside and outside. Some swimming action can be seen below the break, and maybe one of our astute readers can shed some light on this underwater adventurer’s bill of materials.

One of our favorite submarines is the 2017 Hackaday Prize winner, The Open Source Underwater Glider. For a more artistic twist on submersibles, the Curv II is one of the most elegant we have seen.

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Case Mod Takes “All In One” Printer To The Next Level

May 15, 2018 by 14 Comments

You’ve seen printers with scanners in them, printers with copiers in them, even ones with the ancient technology known as “facsimile” built-in. But have you ever seen a printer with a full gaming computer built into it? No? Well, you still haven’t, technically. There’s no printer to be had anymore inside this re-purposed HP Photosmart 6520 case, but it’s probably the closest we’re going to get.

[Jacob Lee] wrote in to share this awesome build with us, which sees the motherboard, graphics card, ATX power supply, and hard drives all fit seamlessly into the shell of a disused “All-in-one” style printer. Incredibly, he even managed to integrate an LCD into the top; which hinges open when in use and gives a look down into the madness that makes this build tick.

To say there’s a lot of hardware packed into this thing is an understatement. Which is all the more impressive when you consider that he] didn’t take the easy way out for any of it. He could have used a mini-ITX motherboard, or a slim PSU. He could have even dropped the graphics card for integrated. No, [Jacob] is clearly a subscriber to the “Go big or go home” ethos.

As if putting all this gear inside of a normal looking printer case wasn’t impressive enough, he even went as far as adding female ports for Ethernet, HDMI, and USB on the rear of the device to give it a stock look. He mentions there’s some room for improvement with the USB ports, but the power switch and IEC port really look like they could have been original components.

In the age of the Raspberry Pi and other diminutive computers, we don’t see too many proper desktop computer projects anymore. Fewer still that are so well executed and creative. We don’t know how many other people might be trying to stick a computer in a printer case, but if they’re out there, the bar has just been set pretty high.

Dark Field Microscopy On The Cheap With A PCB

May 15, 2018 by 4 Comments

It might seem like a paradox that you want a dark field to see things with an expensive microscope. As [IMSAI Guy] explains, a dark field microscope doesn’t make the subject dark. It makes the area surrounding the subject dark. After selling his expensive microscope, he found he missed having the capability, so he decided to make one cheaply. You can see how he did it in the video, below.

Dark field microscopy gives better contrast and resolution by discarding light that shines directly through or reflects directly from a sample. The only light you see is any that scatters. If you think about a normal microscope, you can imagine a cone of light coming from the top or the bottom. The tip of the cone hits the sample and then spreads back out into another cone of light. What hits your eye –well, actually, the eyepiece — is all the light from that cone. In a dark field instrument, the illumination cone is hollow — the light is just a ring. That means any light the sample doesn’t scatter gets blocked by a stop in the objective. When there is no sample, there’s no unblocked light, so you see a “dark field.”

Light that either refracts through the sample (from below) or bounces off a feature (from the top) will wind up in the hollow area that passes through the objective and you’ll see the image. It may surprise you that you may already have a piece of dark field technology on your desk. Optical computer mice that can work on glass surfaces use this same technique. If you want to see some examples and a diagram of how it all works, we did a post on a similar lower tech mod. There’s also Wikipedia.

The secret to doing this cheaply was to get a used dark field objective with a little rust on the barrel and then modify them with a custom PC board to create an LED ring light. This is different from the usual illuminator which shines a light through a patch stop to block the inner light. In this case, the light is made into a ring shape by virtue of the arrangement of the LEDs.

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Lucky Cat POV Display Ditches The Waving And Windmills Out Of Control

May 15, 2018 by 10 Comments

If you’ve been in a Japanese restaurant, you’ve probably seen a maneki-neko, the lucky cat charm, where a cat welcomes you with a beckoning arm. It’s considered to bring good luck, but we’re not sure if [Martin Fitzpatrick] is pushing his luck with this Lucky Cat POV display. He hacked one of the figurines so the arm forms a persistence of vision (POV) display, where blinking LEDs on the paw create a dot-matrix style display.

Inside the hapless neko is a Wemos D1, motor driver, and a few other components that turn the cat into a working display. The five LEDs he attached to the paw are wide enough to display 5×7 characters. The tricky part in the mechanical design is getting signals from a stationary base to a spinning arm(ature). In this case it was easily solved with a 6-wire slip ring from Adafruit. [Martin] revs the lucky cat up using a brushed DC motor and a couple of gears.

The ESP8266 is running MicroPython — the combination should make this a snap to hook into any web service API you want to display your own messages. Right now the arm doesn’t have positional awareness so the message isn’t locked in a single position like it would be if a hall effect sensor was used. But [Martin] says there’s plenty of room left inside the cat and a future upgrade could include stashing the batteries inside for a cordless, all-in-one build. If he takes that on it’s a perfect time to add some type of shaft encoding as well.

Check the Lucky Cat showing off in the clip after the break.

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