arduino

2938 Articles

Stop Motion With The Time Glove

November 9, 2017 by 29 Comments

What do you get when you put an ultra-bright LED in the palm of a glove, and strobe it controlled by an accelerometer? A Time Control Glove! In creator [MadGyver]’s own words, it’s “just a stroboscope with frequency adjustment” but the effect is where all the fun is.

The Time Control Glove uses the stroboscopic effect, which many of us have seen used in timeless water drop fountains where the strobe rate makes drops appear to change speed, freeze in place, and even change direction. [MadGyver] made the entire assembly portable by putting it into a glove. An on-board accelerometer toggles the strobe in response to a shake, and the frequency is changed by twisting the glove left or right. The immediate visual feedback to the physical motions is great. The whole effect is really striking on the video, which is embedded below.

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Hackaday Prize Entry: Reflowduino, The Open Source Reflow Oven Controller

November 7, 2017 by 34 Comments

Face it — you want a reflow oven. Even the steadiest hands and best eyes only yield “meh” results with a manual iron on SMD boards, and forget about being able to scale up to production. But what controller should you use when you build your oven, and what features should it support? Don’t worry — you can have all the features with this open source reflow oven controller.

Dubbed the Reflowduino for obvious reasons, [Timothy Woo]’s Hackaday Prize entry has everything you need in a reflow oven controller, and a few things you never knew you needed. Based on an ATMega32, the Reflowduino takes care of the usual tasks of a reflow controller, namely running the PID loop needed to accurately control the oven’s temperature and control the heating profile. We thought the inclusion of a Bluetooth module was a bit strange at first, but [Timothy] explains that it’s a whole lot easier to implement the controller’s UI in software than in hardware, and it saves a bunch of IO on the microcontroller. The support for a LiPo battery is somewhat baffling, as the cases where this would be useful seem limited since the toaster oven or hot plate would still need a mains supply. But the sounder that plays Star Wars tunes when a cycle is over? That’s just for fun.

Hats off to [Timothy] for a first-rate build and excellent documentation, which delves into PID theory as well as giving detailed instructions for every step of the build. Want to try lower-end reflow? Pull out a halogen work light, or perhaps fire up that propane torch.

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Measuring Airflow In An HVAC System

November 4, 2017 by 10 Comments

[Nubmian] wrote in to share his experiments with measuring airflow in an HVAC system. His first video deals with using with ultrasonic sensors. He found an interesting white paper that described measuring airflow with a single-path acoustic transit time flow meter. The question was, could he get the same effects with off-the-shelf components?

[Nubmian] created a rig using a pair of typical ultrasonic distance sensors. He detached the two transducers from the front of the PCB. The transducers were then extended on wires, with the “send” capsules together pointing at the “receive” capsules. [Nubmian] set the transducers up in a PVC pipe and blew air into it with a fan.

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Listening For Hand Gestures

November 1, 2017 by 15 Comments

[B. Aswinth Raj] wanted to control a VLC player with hand gestures. He turned to two common ultrasonic sensors and Python to do the job. There is also, of course, an Arduino. You can see a video of the results, below.

The Arduino code reads the distance from both sensors — one for the left hand and the other for the right. This allows the device to react to single hand gestures that get closer or further away from one sensor as well as gestures involving both hands. For example, raising your left hand and moving it closer or further away will adjust the volume. The right hand controls rewind and fast forward. Raising both hands will start or stop playback.

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Add Intuitiveness To OpenSCAD With Encoders

November 1, 2017 by 44 Comments

The first time I saw 3D modeling and 3D printing used practically was at a hack day event. We printed simple plastic struts to hold a couple of spring-loaded wires apart. Nothing revolutionary as far as parts go but it was the moment I realized the value of a printer.

Since then, I have used OpenSCAD because that is what I saw the first time but the intuitiveness of other programs led me to develop the OpenVectorKB which allowed the ubiquitous vectors in OpenSCAD to be changed at will while keeping the parametric qualities of the program, and even leveraging them.

All three values in a vector, X, Y, and Z, are modified by twisting encoder knobs. The device acts as a keyboard to

  1. select the relevant value
  2. replace it with an updated value
  3. refresh the display
  4. move the cursor back to the starting point

There is no software to install and it runs off a Teensy-LC so reprogramming it for other programs is possible in any program where rotary encoders may be useful. Additional modes include a mouse, arrow keys, Audacity editing controls, and VLC time searching.

Here’s an article in favor of OpenSCAD and here’s one against it. This article does a good job of explaining OpenSCAD.

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Hackaday Prize Entry: Arduino Video Display Shield

October 30, 2017 by 18 Comments

The Arduino is the standard for any introduction to microcontrollers. When it comes to displaying video, the bone stock Arduino Uno is severely lacking. There’s just not enough memory for a framebuffer, and it’s barely fast enough to race the beam. If you want video from an Arduino, it’s either going to be crappy, or you’re going to need some magic chips to make everything happen.

[MagicWolfi]’s 2017 Hackaday Prize entry consists of an video display shield that would be so easy to use that, according to the project description, it could be a substitute for the classic Blink sketch.

The project centers around the VLSI VS23S010D-L chip, which packs 1 Megabit SPI SRAM with serial and parallel interfaces. An integrated video display  sends the composite video signal to display, with the mode depending on how many colors and what resolution is desired: for instance, at 640×400 you can display 16 colors. As he describes it, not 4K video but definitely Joust. The chip expects 3.3 V logic so he made use of a MC74LVX50 hex buffer to tailor the Arduino’s 5 V. Currently he’s working on revision two of the shield, which will include SPI flash memory.

You can follow along with the project on Hackaday.io or the current shield design can be found in [MagicWolfi]’s GitHub repository.

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SimpleSumo Bots Teach More Than Fighting

October 28, 2017 by 2 Comments

[MechEngineerMike] wrote in to share the enthusiasm over SimpleSumo, a series of open source, customizable robots he designed for mini-sumo battling and much more. For the unfamiliar, mini-sumo is a sport where two robots try to push each other out of a ring. [Mike]’s bots are simplified versions designed for education.

[Mike] was inspired by a video of some kids building mini-sumo bots who were doing anything and everything to personalize them. He vowed to make his own affordable, easy-to-build bots with education firmly in mind. His other major requirement? They had to be as easily customizable as that one potato-based toy that eventually came with a bucket of parts. As of this writing, there are 34 interchangeable accessories.

[Mike]’s first idea was to build the bots out of custom 3D-printed building blocks. He soon found it was too much work to print consistent blocks and switched to a modular cube-like design instead. SimpleSumo bots can do much more than just fight each other. [Mike] has written programs to make them flee from objects, follow lines, find objects and push them out of the ring, and beep with increasing frequency when an object is detected.

The bots are completely open source, but [Mike] sells kits for people who can’t print the parts themselves. He’s made a wealth of information available on his website including links to outside resources about mini-sumo, Arduino, programming, and 3D design. How about a complete series of assembly videos? First one is after the break.  Don’t know how to build a battle ring? He’s got that covered, too.

For a sumo bot that’s more brains than brawn, check out Zumo Red, the smart sumo.

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