Using State Machines In Your Projects

May 27, 2014 by Will Sweatman 21 Comments

arduino, 16 button keypad and LCD display

[Tony] has developed a method of using a state machine to validate keypad inputs. His method checks the commands character by character as they are entered in by a 16 button keypad. State machines are often used to break down complex problems into sequential tasks, making code development easier. While [Tony’s] example uses the keypad, Arduino Uno, and a character LCD, the theory can be applied to numerous projects, such as this Dahlander motor switch.

As you see, state machines can be very versatile. Stick around after the break as we take a look at [Tony’s] state machine and provide a brief explanation of how it all works. Continue reading “Using State Machines In Your Projects” →

Developed On Hackaday: Front Panels And Beta Testers Program

May 27, 2014 by Mathieu Stephan 7 Comments

We’re pretty sure that most of our readers already know it by now, but we’ll tell you anyway: the Hackaday community (writers and readers) is currently developing an offline password keeper, the Mooltipass. As it has been more than two weeks since we wrote an article about our progress, today’s will be about the Mooltipass front panels and our beta testers program.

At the end of our mechanical design rundown article we showed that we were originally planning to put a slightly tinted acrylic panel on top of our device. We however could still make out the Mooltipass’ insides, which wasn’t in line with the nice professional look we wanted. We then designed another front panel, one which was transparent above the OLED screen/LEDs and opaque (black) on top of the rest. To our surprise the result still wasn’t as good as we had hoped, as the contrast between the front panel and the screens/LEDs was too big. We finally came up with the panel shown above (see GitHub repository folder) which combines the two techniques previously described. As it is still in China, we’ll show you the final result when we get it in our hands.

We launched around 10 case prototypes in production, they will soon be shipped to our current contributors/advisers together with the smart cards chosen by Hackaday readers. In the meantime we sent our official call for beta testers to our mailing list recipients and hackaday.io followers, in which we asked them to fill a small form that will allow us to know them a bit better. We asked about their home/work computer setup, their level of expertise, their willingness to contribute to the prototype cost and finally specifics about who would use the Mooltipass they’d receive. We are targeting a broad range of users but also testers that will provide us with detailed feedback and clear bug reports.

We also spent quite a while searching for cheaper alternate parts that could be sourced in relatively big quantities. This is usually an overlooked aspect of a project so we preferred to tackle this as soon as possible. In a few weeks the contributors and I will receive all the components required to assemble our final prototype (front panels / case / top & bottom PCBs / smart cards) and it will be time to write a new update. Want to stay informed? You can join the official Mooltipass Google Group or follow us on Hackaday Projects.

Standing in front of a gravity based pen plotter

Plotterbot Drawing Daleks

May 27, 2014 by Mike Szczys 9 Comments

Two strings, two motors, and some very creative software. That’s the magic behind the Plotterbot, which was drawing Daleks when we crossed its path at Maker Faire. This is the Mark II, which was built after cannibalizing Mark I. Unfortunately we can’t tell you what the difference is between the two.

The machine itself is a pretty nice little package. There is a box that hangs on the wall with a motor/spool combination at each end. In the middle of those two is an Arduino Mega with a custom driver shield. It takes an SD card with the drawing files on it. There is also a small touchscreen display which allowed for easy selection of what you’d like drawn on that paper taped to the wall below the unit.

Back when we were running the Trinket contest [Jay] used the Plotterbot to draw a Skull and Wrenches made out of a multitude of smaller Skull and Wrenches. He was nice enough bring that piece of art and present it to us at the Faire. Thanks [Jay]!

Continue reading “Plotterbot Drawing Daleks” →

An Audio Based USB Oscilloscope And Signal Generator For $20

May 27, 2014 by Nick Conn 23 Comments

SoundScope

Are you interested in building a 20kHz 2-channel oscilloscope and a 2-channel signal generator for only $20 with minimal effort? Be sure to check out [Jana Marie’s] Instructable that goes over how to build this awesome tool from a cheap USB audio card.

We have featured tons and tons of DIY oscilloscopes in the past, but this effort resulted in something very well put together while remaining very simple to understand and easy to build. You don’t even need to modify the USB audio card at all. One of the coolest parts of this build is that you can unplug your probe assembly from your USB audio card, and bring it wherever your hacking takes you. After the build, all you need is [Christian Zeitnitz’s] Soundcard Oscilloscope program and you are good to go. One of the major downsides that is often overlooked when using an audio based oscilloscope, is that it is “AC coupled”. This means you cannot measure low-frequencies (including DC signals) using a sound card. Be sure to heed [Jana’s] advice and do not use your built in audio card as an oscilloscope. With no protection circuitry, it is a sure fire way to fry your computer.

What analog projects have you built around an audio interface? We have seen such an interface used for many different applications, including a few fun medical related hacks (be sure to keep safety your first priority). Write in and let us know!

The Electrostatic Theory Of Metal Whiskers

May 27, 2014 by Brian Benchoff 90 Comments

wiskers Thanks to that wonderful ROHS stuff the EU passed more than a decade ago, we should be seeing a few high-profile failures of electronic components due to tin whiskers. These tiny hair-like extrusions of metal found most commonly in lead-free solder have destroyed billion dollar satellites and shut down nuclear reactors, despite no one knowing exactly how these whiskers form. Now there’s a new theory of metal whisker formation (abstract, unless you have access to APS) that actually has predictive power. Here’s the free version of the paper

[V. G. Karpov] from the University of Toledo suggest these whiskers are formed by differences in charge induced by metallurgical anomalies – contamination, differences in the grain of the solder, and oxides. Because of the difference in charge, the whiskers are extruded, for lack of a better word, out from the surface of the solder.

The theory of whisker growth is generally consistent with observed rates of whisker growth and other properties. With this theory, it should even be possible to grow tin whiskers. Why anyone would want to do that other than, ‘because it’s cool’ is anyone’s guess, but there you go.

Running Minecraft On Two Routers

May 27, 2014 by Brian Benchoff 6 Comments

router

[CNLohr] is no stranger to running Minecraft on some weird hardware. Earlier, he built this Linux powered microscope slide… thing to toggle LEDs with redstone levers in Minecraft. Figuring if Minecraft could run on an AVR, he decided to try the same thing on a router, a TP-LINK TL-WR841N to be specific. Like the microscope slide running Linux, this proved to be an easy task. [CNLohr] had another router he could run Minecraft on, and this one could also punch wood. There really was only one thing for him to do.

Like the microscope slide and the wireless router, [CNLohr]’s CNC router is now running a Minecraft server. The phrase, “because it’s there” comes to mind. When connected to the CNC server, the player controls a snow golem (a snowman with a jack ‘o lantern head) with a carrot. Wherever the snow golem goes, the tool head follows, allowing him to carve objects in the world, and on a sheet of MDF secured in the CNC machine.

It’s certainly an odd build, but [CNLohr] was able to carve out a pixeley, blocky Hackaday logo with the snow golem controlled CNC machine. Code here, video below.

Continue reading “Running Minecraft On Two Routers” →

Internet Controlled LED Necktie Lights Up The Party

May 26, 2014 by James Hobson 6 Comments

MIDI Controlled Necktie

Wearable devices are all the rage in certain circles — looking for a project of his own, [Hector Urtubia] decided to give it a shot with this six-LED necktie.

It used to be pretty hard to make an Internet connected device without spending all your time and effort on making the Internet connection possible — until the Pinoccio came along. It’s a tiny Arduino compatible board which has wireless Internet connectivity built right in. It even comes with a rechargeable battery. If you have experience with Arduino programming, this little guy is a cinch to get running.

The tie itself makes use of six NeoPixels, which are chainable, addressable and current regulating RGB LEDs, which means the entire chain of LEDs only requires 1 digital pin-out on the Pinoccio! [Hector] has even written a library that will extend the Pinoccio’s scripting environment so that the pixels can interact directly from the web or API.

To demonstrate the tie, he decided to hook it up to his MIDI keyboard — enjoy:

Continue reading “Internet Controlled LED Necktie Lights Up The Party” →