Hacklet 77 – Projects That Tweet

September 25, 2015 by Adam Fabio 4 Comments

Since it’s launch way back in 2006, Twitter has become a magnet for techies. Maybe it’s the simple interface, maybe it’s the 140 character limit. Whatever the reason, you can find plenty of hackers, makers, and engineers tweeting about their daily activities. It didn’t take long for folks to start incorporating Twitter into their projects. Ladyada’s Tweet-a-watt is a great early example of this. This week’s Hacklet is all about some of the best tweeting projects on Hackaday.io!

We start with [Henry Conklin] and A Twitter account for my dog. [Henry’s] dog [Oliver] loves to bark and finding a solution became his entry to The Hackaday Prize. Rather than bring Cesar Millan in, [Henry] decided to embrace [Oliver’s] vocalizations by sending them up to the cloud. A Raspberry Pi with a USB microphone uses some custom Python code to detect barks and ruffs. The Pi then sends this data to Twitter using the python-twitter library. The Pi is connected to the internet via a USB WiFi dongle. You can see the results of [Henry’s] work on [Oliver’s] own Twitter page!

Next up is [troy.forster] and tweetie-pi. Rather than constantly check his phone or computer, [Troy] wanted a device to read his tweets. A bit of NodeJS code later, and tweetie-pi was born. A Raspberry Pi connected to the internet pulls data through the Twitter stream API. When tweets directed at a pre-configured username are found, the data is sent to a an Emic 2 text to speech module. The Emic reads in that classic DECtalker style voice we all know and love from the movies. [Troy] even added code to properly handle usernames and retweets.

[SirClover] joined the internet of things by creating Home automation system with Twitter, his entry in the 2014 Hackaday Prize. This home automation system is based around an Arduino Leonardo and an Ethernet shield. [SirClover] rolled his own custom PCB to handle relays, a Cds cell, and a 2×16 character LCD. The system can be accessed through a simple web interface. This allows the user to open or close blinds, turn on lights, all that great smart home stuff. Every time it executes a command, the home automation system reports status to Twitter.

Finally we have [Jakob Andrén] with A danceable notification cube, which is [Jakob’s] entry in the 2015 Hackaday Prize. The cube itself is a translucent box that contains a metric crapton of LEDs. 148 Neopixels and 12 3W power LEDs to be exact. All these LEDs are driven by a Teensy 3.1, which serves as the main processor for the entire system. The Teensy reads position data from an MPU6040 IMU. This allows it to change brightness and color as the box is moved around – or “danced”. An ESP8266 provides the cube with data from the interwebs, specifically Facebook and Twitter. The cube lights up and flashes whenever it receives a message.

If you want to see more tweeting projects, check out our new projects that tweet list. Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Drawbacks Of Laser Cut Delrin–and How To Slip Around Them

September 22, 2015 by Sonya Vasquez 34 Comments

Welcome back to part II in this ensemble of techniques with laser-cut Delrin. Thanks for many of the great insights along the way in the comments. In this guide, I’d like to go over some of the more immediate kinks that come to mind when getting started with this material.

Sourcing Delrin Sheets

When it comes to shopping, there are a variety of suppliers to choose from, but there are a few key words and thoughts to keep in mind.

Names

First, Delrin, is the “brand name” that refers to the Acetal homopolymer. Variants may also be labeled, acetal or acetal homopolymer. Delrin’s natural color is a soft white, but dyes can take it into a range of other colors. Black and white are, by far, the most common, though.

Tolerances

In the previous guide, all of the examples were cut from a small range of sheet thicknesses (0.0625[in], 0.09375[in], and .125[in]) sourced from OnlineMetals. As the thickness of the sheet increases, the tolerances on the thickness rating will also become more loose. You might buy a .125[in] plate and find it to be .124[in] in some places and .126[in] in others. If you purchase a .250[in] sheet, however, you’ll find that it may vary as much as .126[in] oversize though!

Buy it Flat

Despite McMaster-Carr being my go-to solution for one-off prototypes where rapid build iterations trump BOM cost, I don’t recommend purchasing Delrin from them as their sheets don’t have a flatness rating and often gets shipped bent in (oddly sized) boxes. (Seriously, has anyone else gotten a few oddly-sized parts in a gigantic McMaster-box before?)

Internal Stresses

Extruded Delrin has internal stresses built up inside of the sheet. There are a variety of reasons why this could be the case, but my biggest hunch is that the extrusion process at the factory results in different parts of the sheets solidifying at different times as the sheet cools, possibly causing some parts of the sheet to tighten from the cooling before other gooier sections have yet to finish cooling. What this means for you is that as your part gets lased out of the sheet, you’re, in a sense, relieving that stress. As a result, the part that you cut–especially for thin sheets–may come out of the laser cutter slightly warped.

Continue reading “Drawbacks Of Laser Cut Delrin–and How To Slip Around Them” →

Rubik’s Solver Uses FAC Machine Building System

September 15, 2015 by Mike Szczys 9 Comments

We love a good Rubik’s Cube solver and the mechanical engineering on this one is both elegant and functional.

This is the first time we remember hearing about the FAC system, which is a standard set of parts which can be used to make any number of mechanical systems. [Wilbert Swinkels] must be a master with the system; the layout of the machine appears simple and uncrowded despite the multiple degrees of freedom built into it. Those include an insertion platform for getting the cube in and out, a gantry for three color sensors, and two axes (three grippers in all) for doing the actual solving. If you’ve used FAC before we want to hear what you think of it in the comments.

[Maxim Tsoy] handled the software which runs on a Rapsberry Pi Compute module. You’ll want to watch the demo video below. First you place the randomized cube on the insertion platform which retracts after the cube is in the grasp of the grippers. These work in conjunction with the color sensor gantry to scan every side of the cube. After a brief pause to compute the solution the grippers go to work.

It is possible to build a solver with just two swiveling grippers. Here’s a really fast way to do it.

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Hackaday’s DC Meetup And Workshops

September 14, 2015 by Mike Szczys 6 Comments

Washington DC has a vibrant hardware hacking community and it was out in force on Saturday night. We had over one hundred people through the door at Nova Labs in Reston, Virginia (DC metro area). This sleek and spacious hackerspace opened their doors for a Hackaday Meetup as part of a weekend packed full of activities.

Blinky hats

RPi powered Teletype machine

LED marquee cube

Wyolum reaction time game

The building that Nova Labs moved into not too long ago is a really well-suited area for a Hackerspace. The front half of the building includes a huge open space which has plenty of room for people to set up the hardware they wanted to show off. The back has a full woodshop, machine shop, and more, with classrooms and conference rooms in between.

Above are a set of hats with addressible LED strings wrapped around them which [ArsenioDev] brought along with him. Several members of the Wyolum team are involved with Nova Labs and they were showing off some LED matrix-based projects like the marquee cube and a 3-player reaction time game. And clacking away all night long is a vintage teletype machine that [Bob Coggeshall] fixed and connected to a Raspberry Pi.

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Turning Smog Into Gemstones And Pollution Awareness

September 9, 2015 by James Hobson 59 Comments

Wait what? The Smog Free Project by [Daan Roosegaarde] is another one of those head scratchers where somehow art, engineering, and a designer collide — to produce what looks like an actual working concept…?

The oddly shaped white tower is essentially a massive air purifier. It’s in Rotterdam this week after over 3 years of research and development. It actually scrubs the air, removes contaminates, and then compresses those particles down into small cubes, or “gem stones”. Going full tilt, it will clean approximately 30,000 cubic meters of air per hour. Continue reading “Turning Smog Into Gemstones And Pollution Awareness” →

Experimental Theater Helps Field Test Haptic Navigation Device

September 4, 2015 by Dan Maloney 7 Comments

The “absorbed device user” meme, like someone following Google Maps on a smart phone so closely that they walk out into traffic, is becoming all too common. Not only can an interface that requires face time be a hazard to your health in traffic, it’s also not particularly useful to the visually impaired. Haptic interfaces can help the sighted and the visually impaired alike, but a smart phone really only has one haptic trick – vibration. But a Yale engineer has developed a 3D printed shape-shifting navigation tool that could be a haptics game changer.

Dubbed the Animotus by inventor [Ad Spiers], the device is a hand-held cube split into two layers. The upper layer can swivel left or right and extend or retract, giving the user both tactile and visual clues as to which direction to walk and how far to the goal. For a field test of the device, [Ad] teamed up with a London theater group in an interactive production of the play “Flatland”, the bulk of which was staged in an old church in total darkness. As you can see in the night-vision video after the break, audience members wearing tracking devices were each given an Animotus to allow them to navigate through the interactive sets. The tracking data indicated users quickly adapted to navigation in the dark while using the Animotus, and some became so attached to their device that they were upset by the ending of the play, which involved its mock confiscation and destruction.

Performing art applications aside, there’s plenty of potential for haptics with more than one degree of freedom. Imagine a Bluetooth interface to the aforementioned Google Maps, or an electronic seeing-eye dog that guides a user around obstacles using an Animotus and a camera. There’s still plenty of utility in traditional haptics, though, as this Hackaday Prize semi-finalist shows.

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How To Build Anything Using Delrin And A Laser Cutter

September 3, 2015 by Sonya Vasquez 58 Comments

Need a simple fab process to go from a humble vector graphic to a final part — in a matter of minutes? The CO₂ laser cutter might be the right choice. As these tools open themselves up to widespread use through hackerspaces, I decided to give Delrin some well-deserved time under the spotlight.

The laser cutter yet-again proves itself a formidable tool with the construction of GameCube-Bot V2

This guide is a brief collection of tips and techniques that I’ve either learned from others or discovered on my own over the last couple years working with laser-cut Delrin (a.k.a Acetal) for functional prototypes. I hope this guide serves you well as we keep exploring the limits of the material.

As a disclaimer, keep in mind that in no way are these techniques unique or limited to Delrin. Many are not only years old but also common practice in either engineering design or the local machine shop. This article simply highlights the techniques shown here that perform both repeatably and predictably with Delrin and a couple hand-tools, and I hope to share them with a growing audience of laser cutter enthusiasts.

Continue reading “How To Build Anything Using Delrin And A Laser Cutter” →