Accelerometers Are Actually Quite Simple

December 24, 2014 by Matt Freund 13 Comments

An accelerometer is the ubiquitous little sensor that tells your tablet when to flip orientation or informs the brain of your quadcopter how closely its actual actions are matching your desired ones. In a quick three minutes, [Afroman] explains what is inside an accelerometer and how they work.

It turns out the tiny devices that report acceleration in one, two or three dimensions are not powered by magic complicated mechanisms but very simple Micro Electro-Mechanical Systems or “MEMS.” MEMS are similar to copper/silver/gold-wired integrated circuits except in a MEMS circuit conductive silicon is used and they actually physically move, but only just a bit.

The secret is in creating microscopic capacitors along a weighted lever that flexes in response to changes in velocity. When the plates flex the distance between them changes which alters the capacitance. This translates physical motion into voltage which can then be interpreted by the rest of your circuit. The chemistry behind MEMS is interesting too.

This Christmas when your laptop’s power cord clotheslines your cousin’s kid, your hard drive has a chance of parking the head (on the drive, not on the child) between fall and impact and preventing damage (to the drive, not to the child) because of an accelerometer. If bad roads cause you to drift into the ditch, it is an accelerometer that senses the crash and tells your airbag to deploy before your body hits the steering wheel.

The MEMS market is exploding right now and for us hackers in particular, Wearables are looking to be a big part of that growth.

Home Automation With The Amazon Echo

December 24, 2014 by Brian Benchoff 22 Comments

The Amazon Echo is the answer to Apple’s Siri, Microsoft’s Cortana, and [Orwell]’s Telescreen – a device that sits in your home, listens to everything you say, and will gladly oblige if you want to buy something on Amazon. Brilliant. Despite being a pretty cheap device, there’s not really a whole lot it can do; sure, Echo, or more accurately Alexa, the personality in the Echo, can tell you the weather, queue up a playlist, or read a Wikipedia entry, but there’s a definite lack of imagination when it comes to the Echo.

Now, thanks to some clever API hacks, you can do far more with the Echo. [Noel] is using the Echo to turn lights in his house on and off, ring his home phone, and basically everything else you can do with some wire and a bit of code.

[Noel] got his idea from [Owen Piette] who recently investigated the Echo API. It’s all unpublished by Amazon, but it is possible to poll the todo list for random key phrases. By polling this API and getting new results, it’s pretty easy to set up some logic to do arbitrary actions.

Right now [Noel] can turn a light on and off and call his phone, but the sky really is the limit here. If you have a web-enabled thermostat, Alexa can turn the heat on or off. Want to text yourself something? That’s easy too. Anything that can be put in a todo list can be done with the Echo, the only obstacle is doing all the programming and electronics.

Website Response Speedometer

December 24, 2014 by Brian Benchoff 9 Comments

Here’s something that will probably make it to a wall right next to the people responsible for the Hackaday servers sometime soon, and should be something every web dev should build at some point: a website response meter, an analog gauge that will tell you how long it takes to reach your website.

The build is simple enough, with a micro servo working as a gigantic analog gauge. There are also a pair of four-digit, seven-segment displays for displaying a digital number and the number of website requests per second. There’s also an 8×8 matrix of bi-color LEDs for showing a green happy face or a red frowny face, just in case all that data wasn’t self-evident to the uninitiated.

All the electronics are handled by an Arduino, but what really makes this build useful, or even possible, is the bit of code that runs on a computer. The computer uses an API from New Relic, a software analytics company, to come up with the response time and requests per second. That data is pulled down and piped up to the Arduino that displays everything on a beautifully milled acrylic sheet.

Fan-tastic Box Fan Computer Fan

December 24, 2014 by Rich Bremer 48 Comments

Sure, it’s a great idea to keep your computer components cool…. but why? PC components consume energy and in doing so they generate heat. That heat can reduce overall system performance or even damage specific parts. You’ve certainly noticed those huge aluminum finned heatsinks covering critical components in your PC. They are there for a reason, to keep things cool. Most PC’s have at least one fan, if not several, usually only a few inches in diameter. If a small fan does an okay job at cooling a PC, how would a large fan do….. we’re talking a really large fan? [Envador] wanted to find out and made a PC case with the largest fan possible.

Looking at the photo it is pretty obvious that PC case frame is fabricated from standard PVC piping. The side of the case is hinged to allow access to the internal components. That huge set of blades started out as an off-the-shelf box fan. It was taken apart and mounted directly to the PVC case door. It wouldn’t make too much sense to have side panels on this case since the fan is so large. So, instead of solid sides [Envador] used chrome-plated plastic grills that are usually reserved for fluorescent ceiling lights. Perforated metal strapping holds all the drives, power supply and mother board in place.

Unfortunately, [Envador] doesn’t give any before/after temperature data but states that the PC tops out at 95°F and he hasn’t had any problems with computer performance.

An OLED Ring For Bluetooth Notifications

December 24, 2014 by Brian Benchoff 27 Comments

Wearables are the next frontier of amateur electronics, and [Kevin]’s Arduboy ring (link dead, try Internet Archive) is one of the best examples we’ve seen yet.

Inside the Arduboy is an nRF51822 – a chipset with Bluetooth Low Energy, an ARM Cortex M0,256k of Flash, and 16k of RAM. There’s also a an OLED and a touch button for displaying notifications from a phone, with the ability to reply to these notifications.

The enclosure for the ring is rather interesting. It’s a bit thick, but that’s for a reason – there’s a 40mAh battery stuffed along the sides of the ring. The enclosure itself is 3D printed to spec, and contrary to some beliefs, there’s nothing wrong with bending a LiPo cell once. Sure, it only has four hours of battery life with the display on, but it has a 24 hour battery life in standby mode, making it almost useful as an everyday wearable.

This is [Kevin]’s second wearable, the first being the Ardubracelet, an extremely interesting OLED bracelet with three different displays. The Arduboy is much more compact and comes extremely close to looking like a product. You can check out the video of it below.

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TRINKET EDC CONTEST DRAWING #4 RESULTS

December 23, 2014 by Adam Fabio No comments

The fourth of five random drawings for Hackaday’s Trinket Everyday Carry Contest was held tonight. The winner is [davish] with his entry, Trinket Watch.

[davish] loves the current crop of smartwatches, but he wants one he can truly call his own. He’s using the Pro Trinket along with an Adafruit 1.3″ OLED for display duties. That little OLED can show a lot more than just numbers though. [davish] already has Adafruit’s logo demo running on the device. Trinket Watch is going to start out as a simple Arduino coded “dumbwatch”. After the basics of time and date are out of the way, [davish] hopes to add a Bluetooth module and turn Trinket Watch into a full-fledged smartwatch.

We hope [davish] enjoys his new Cordwood Puzzle from The Hackaday Store. No jigsaws here, cordwood is a puzzle that involves solder! If you get a piece wrong, it’s time to break out that solder wick and fix your mistake. The puzzle is built using the cordwood assembly technique which was popular in the 1950’s and 1960s. We’re not kidding about it being a puzzle either – there are no instructions for this kit! [davish] will know he’s got it right when all 3 LEDs light up.

If you didn’t win this week, all is not lost, you still have one more chance to win a random drawing! Our next drawing will be on 12/30/2014 at 9pm EST. The prize will be a Teensy 3.1 and audio adapter as a prize. To be eligible you need to submit your project as an official entry and publish at least one project log during the week.

The main contest entry window closes on January 2, 2015 – but don’t wait for the last minute! Hit the contest page and build some awesome wearable or pocketable electronics!

Real-Time Thermal Projection Saves Your Tastebuds From The Hot Stuff

December 23, 2014 by Sonya Vasquez 18 Comments

With another wave of holiday parties about to land on our doorstep, we still haven’t found a great way to stop scalding our tongues each time [Uncle Dave] pours us an enticing cup of boiling cocoa.

Thankfully, [Ken] has both you and your holiday guests covered with a clever trick that takes the data from a FLIR ONE and projects a heat profile onto the surface it’s observing. Here, [Ken] has superimposed his FLIR ONE data onto his kitchen table, and he’s able to visualize 2D heat profiles in near-real-time.

If you haven’t started quantifying yourself recently (and what are you waiting for?), the FLIR ONE is yet another opportunity to help you become more aware of your surroundings than you are now. It’s a thermal camera attachment for your iPhone, allowing you to see into the infrared band and look at the world in terms of heat. We’ve covered the FLIR ONE before, and we’ve seen ways of making it both clearer and more hacker-friendly.

As we tip our hats to [Ken], we’d say he’s a generous fellow. This hack is a clever inversion of the normal use case where you might whip out your FLIR-ONE-enabled iPhone and warn your cousins not to try the hot chocolate for a few more minutes. With [Ken’s] solution, the data is right there on your condiments and in plain sight of everyone, not just for you with your sweet, Star-Trek-augmented iPhone.

Continue reading “Real-Time Thermal Projection Saves Your Tastebuds From The Hot Stuff” →