Mrs. Penny’s Driving School — Hardware Workshop In Dallas

April 15, 2016 by 8 Comments

In case you haven’t noticed, the Hackaday community is making more of an effort to be a community AFK. We’re at VCF East this weekend, have the Hackaday World Create Day quickly approaching, Hackaday | Belgrade a few days ago, and Hackaday Toronto next week just to name a few in close proximity to this post.

As promised, or threatened, depending on which end of the stick you’re on I will be teaching an electronics class at the Dallas Makerspace every 3rd Saturday of the month. The goal of these classes is to help you overcome the barrier between a hardware idea and having that hardware in your hand. I’m not an expert in PCB design or layout, but I’ve found more ways to do it wrong than I’d probably admit too and this is my way of sharing what I’ve painfully learned through trial and error. At the time of writing this article there are still a few spots available in the first class, follow the above link for tickets.

Images of my failed hopes and dreams wonderfully captured courtesy of [Krissy Heishman]

Class 1

In our first 6 hour session we’ll take a basic, high-level idea and work our way down. For example: our first project will be an AVR development board. This is something common enough that everyone will know what it is (an Arduino is an AVR development board, just in case my mom is reading this). We won’t be making an Arduino clone part-for-part but taking the Arduino idea and making it our own custom board. Maybe we add some terminal blocks instead of DuPont headers or perhaps we want a real time clock and a slide potentiometer on the board. We can do that if we want, you can’t stop us.

So class number 1 is a crash course in Eagle schematic capture and PCB layout. Since this is only 6 hours worth of class time and we need to have boards and parts ordered when we leave we won’t be getting too complicated with our design.

Class 2

By the time we meet for our second session we should have taken delivery of our shiny new PCBs and our parts order should have long since been delivered from the distributor (Mouser is more or less an hour drive from the Dallas Makerspace, not that we’ll pick the parts up at will-call for this project, but it’s nice to have the option). We will spend the second 6 hour session assembling and testing our boards. If we need to make changes to our boards we can talk about that as a part of the design process. Depending on how long assembly takes we can brainstorm some ideas for the next round of Mrs. Penny’s Driving School classes which will continue the following 3rd Saturday of the month.

Flappy Bird On An… E-Cigarette?

April 15, 2016 by 27 Comments

Okay, now we’ve seen it all. Someone put the effort in to port Flappy Bird… to run on an e-cigarette. An eVic-VTC Mini to be precise. So now, between puffs, you can play one of the most frustrating games ever.

The SDK for the e-cig is available on GitHub, which was provided by a group of Redditors last year. If you’re interested in the game, and happen to have this model of e-cig, [Bank] has provided download and flashing instructions in the description of the YouTube video.

As one Reddit user points out:

“Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should.”

To which the creator, [Balázs Bank], responded with the download links to install it yourself. Has science gone too far?

Continue reading “Flappy Bird On An… E-Cigarette?” →

Measuring Parts Badly For Accurate Reverse Engineering

April 15, 2016 by 107 Comments
Previous headquarters of Useful Thing Inc.
Previous headquarters of Useful Thing Inc. They made the best widget you could buy in the 80s.

Like most hackers, I’ve run into a part that looks like it might do what I want, but the only documentation came from a company so thoroughly defunct their corporate office is now a nail salon and a Subway.

So, as any hacker who’s wandered through a discount store with a spare twenty, at one point I bought a Chinese caliper. Sure it measures wrong when the battery is low, the temperature has changed, if I’ve held it in my hand too long, the moon is out, etc. but it was only twenty dollars. Either way, how do I get accurate measurements out of it? Well, half-wizardry and telling yourself educated lies.

There are two golden rules to getting accurate measurements by telling lies. It may be obvious to some, but it took me quite a bit of suffering to arrive at them.

  1. Engineers are lazy. So lazy. Most things are going to be even numbers, common fractions, and if possible standard sizes. If sheets and screws come in 2 and 3mm then you bet you’re going to see a lot of 2mm and 3mm features. Also, even though the metric world is supposedly pure, you’re still going to see more 0.25 (1/4) mm measurements than you are .333333 (1/3) mm measurements. Because some small fractions are easier to think about than decimals.
  2. Your eyes lie. If it matters, measure it to be sure.

Continue reading “Measuring Parts Badly For Accurate Reverse Engineering” →

Poor Man’s Time Domain Reflectometer

April 15, 2016 by 25 Comments

A time domain reflectometer, or TDR, is an essential piece of test gear when working on long cables. The idea is simple: send a pulse down the cable and listen for the reflection from the far end. The catch is that pesky universal constant, the speed of light.

The reason the speed of light is an issue is that, in a traditional system, the pulse needs to be complete before the reflection. Also, time is resolution, so a 1 GHz sampling rate provides a resolution of about 10 centimeters. [Krampmeier] has a different design. He sends variable length pulses and measures the overlap between the outgoing and reflected pulses. The approach allows a much simpler design compared to the traditional method.

Continue reading “Poor Man’s Time Domain Reflectometer” →

Weight Tracking, Wise Cracking IoT Bathroom Scale

April 15, 2016 by 12 Comments

For those fighting the battle of the bulge, the forced discipline of fitness bands and activity tracking software might not be enough motivation. Some who are slimming down need a little gentle encouragement to help you lose weight and keep it off. If that sounds like you, then by all means avoid building this weight-tracking IoT scale with an attitude.

Then again, if you live in fear of your scale, [Jamie Bailey]’s version is easy to hate, at least when your numbers are going in the wrong direction. Centered around a second-hand Wii Balance Board talking to a Raspberry Pi via Bluetooth, the scale really only captures your weight and sends it up to InitialState for tracking and feedback. Whether the feedback is in the form of jokes at your expense is, of course, is entirely up to you; if you’d rather get gentle nudges and daily affirmations, just edit a few files. Or if your tastes run more toward “Yo momma so fat” jokes, have at it.

Bathroom scales are a good hacking target, whether it’s reverse engineering a digital scale or eavesdropping on a smart scale. This build is snarky good fun, and if nothing else, it’s good for pranking your roommate. Unless your roommate is your husband or wife, of course. That’s just – no.

A Star Tracking Telescope Mount

April 14, 2016 by 20 Comments

[Chris] recently got his hands on an old telescope. While this small refractor with an altitude-azimuth mount is sufficient for taking a gander at big objects in our solar system, high-end telescopes can be so much cooler. Large reflecting telescopes can track the night sky for hours, and usually come with a computer interface and a GOTO button. Combine this with Stellarium, the open source sky map, and you can have an entire observatory in your back yard.

For [Chris]’ entry into the 2016 Hackaday Prize, he’s giving his old telescope an upgrade. With a Raspberry Pi, a few 3D printed adapters, and a new telescope mount to create a homebrew telescope computer.

The alt-az mount really isn’t the right tool for the astronomical job. The earth spins on a tilted axis, and if you want to hold things in the night sky still, it has to turn in two axes. An equatorial mount is much more compatible with the celestial sphere. Right now, [Chris] is looking into a German equatorial mount, a telescope that is able to track an individual star through the night sky using only a clock drive motor.

To give this telescope a brain, he’ll be using a Raspberry Pi, GPS, magnetometer, and ostensibly a real-time clock to make sure the build knows where the stars are. After that, it’s a simple matter of pointing the telescope via computer and using a Raspberry Pi camera to peer into the heavens with a very, very small image sensor.

While anyone with three or four hundred dollars could simply buy a telescope with similar features, that’s really not the point for [Chris], or for amateur astronomy. There is a long, long history of amateur astronomers building their own mirrors, lenses, and mounts. [Chris] is just continuing this very long tradition, and in the process building a great entry for the 2016 Hackaday Prize

The HackadayPrize2016 is Sponsored by:

What’s A Piezo Optomechanical Circuit?

April 14, 2016 by 17 Comments

Ever hear of a piezo-optomechanical circuit? We hadn’t either. Let’s break it down. Piezo implies some transducer that converts motion to and from energy. Opto implies light. Mechanical implies…well, mechanics. The device, from National Institute of Standards and Technology (NIST),  converts signals among optical, acoustic and radio waves. They claim a system based on this design could move and store information in future computers.

At the heart of this circuit is an optomechanical cavity, in the form of a suspended nanoscale beam. Within the beam are a series of holes that act as mirrors for very specific photons. The photons bounce back and forth thousands of times before escaping the cavity. Simultaneously, the nanoscale beam confines phonons, that is, mechanical vibrations. The photons and phonons exchange energy. Vibrations of the beam influence the buildup of photons and the photons influence the mechanical vibrations. The strength of this mutual interaction, or coupling, is one of the largest reported for an optomechanical system.

In addition to the cavities, the device includes acoustic waveguides. By channeling phonons into the optomechanical device, the device can manipulate the motion of the nanoscale beam directly and, thus, change the properties of the light trapped in the device.  An “interdigitated transducer” (IDT), which is a type of piezoelectric transducer like the ones used in surface wave devices, allows linking radio frequency electromagnetic waves, light, and acoustic waves.

The work appeared in Nature Photonics and was also the subject of a presentation at the March 2016 meeting of the American Physical Society. We’ve covered piezo transducers before, and while we’ve seen some unusual uses, we’ve never covered anything this exotic.