Rotating Plants For Time-Lapse Purposes

September 12, 2014 by 13 Comments

Automating the growing process of plants and vegetables is an increasing trend among gardening enthusiasts and hobbyists. It’s no surprise, either, with microcontrollers, moisture sensors, Co2 detectors, and even time-lapse cameras with rotating wooden rigs that are in the hands of millions of amateur gardeners around the world.

This project by [Liz] helps to document the sprouting process of her tiny grapefruit bonsai tree that started to flourish at her apartment in Chicago.

Similar rigs can be used for practically any type of indoor plant. They can also be modified to move the plants and vegetables depending on how much light they are getting. Even further, just add some code to splice the photographs together and you’ve got yourself a custom setup that can produce animated GIF files to be uploaded easily to the internet. Pages and pages of happy and healthy growing plants unearthing themselves from the ground up would be pasted all over the web showing the entire sprouting process. An example video of this by [Liz] is embedded below.

Continue reading “Rotating Plants For Time-Lapse Purposes” →

Extrinsic Motivation: And You Thought Inverted Pendulums Were Hard

September 11, 2014 by 24 Comments

An extremely common project for a control systems class is the inverted pendulum. Basically, it’s a robot mounted on a linear rail, a hinge, and a pendulum sticking straight up in the air. Get your algorithms right, and you have a pendulum that seemingly resists the inexorable pull of gravity and a great understanding of how Segways, balancing robots, and quadcopters work.

[zakowy] is taking this to the next level with his entry to The Hackaday Prize. It’s an inverted pendulum with two counter-rotating propellers in a gimballed fan, and the most unstable UAV design we’ve ever seen.

The mechanics of the build consist of a carbon and epoxy frame, with a motor mount that can move in the X and Y axes. This mount holds two brushless motors and is actuated with rather large pitch and roll servos. The electronics consist of the usual suite of sensors found in a quadcopter – gyros, accelerometers, magnetometers, and a barometric altimeter. Everything is controlled by an Arduino Due, getting commands from an RC receiver and sending telemetry back to a computer

[zakowy]’s project didn’t make the cut for the quarterfinalist selection, but he is undeterred. He’s building this strange contraption because he can, not because we’re dangling some great prizes in front of his nose. Right now, [zakowy] is working on a testing rig. This thing will fly, make no mistakes about that.

Videos available below.

SpaceWrencherThis project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.

Continue reading “Extrinsic Motivation: And You Thought Inverted Pendulums Were Hard” →

Global Radiation Monitoring Network Update

September 11, 2014 by 30 Comments

Things have been busy at Global Radiation Monitoring Network Central Command. As a semifinalist in the Hackaday Prize, project creator [Radu Motisan] has quite a bit of work to do. He’s not slacking off either. With 33 project logs (and counting), [Radu] has been keeping us up to date with his monitoring network and progress on uRADMonitor , the actual monitoring hardware.

[Radu’s] latest news is that he’s ready to go into production with model A of the uRADMonitor. Moving from project to production can be an incredible amount of work due to sourcing parts, setting up assembly houses, and dealing with any snags that come up along the way. We’re sure [Radu] can handle it, though.

The network of uRADMonitors is also growing. A new monitor was just installed in Prescott, Arizona. This is the 10th unit in the USA.  You can view the map, data, and graphs of global radiation live on the uRADMonitor website.

SpaceWrencherThe project featured in this post is a semifinalist in The Hackaday Prize.

Changing Poi Colors Based On Speed And Velocity

September 11, 2014 by 5 Comments

LED toys have become synonymous with the underground rave culture as party-goers gaze into vortexes of spinning light known as poi. Most of these objects come pre-programmed, but some can be custom coded. However, only a few tap into an accelerometer changing the colorful circles of energy depending on how fast they move through space. One stunning example is this LED device called the ‘Center Flee’ that translates accelerometer data into sequences of alternating RGB colors.

The LED values are ‘printed’ to the tethered objects at specific points in the rotational arc. The devices are controlled with an Arduino, and a XBee wireless module transmits data to a computer nearby, eliminating the need to manually remove an SD card after each spinning session.

When spun, the poi acts like a colorful, twirling extension of the performer that produces a mesmerizing, vibrant effect. It’s nice to see the progression of glow sticks tied to shoelaces into g-force sensing devices that can captivate surrounding audiences.

Other examples of similar types of ideas include this accelerometer poi that was cut with a CNC machine and these LED staffs for the ultimate portable rave.

Below is a video playlist of the Center Flee being tested out.

Continue reading “Changing Poi Colors Based On Speed And Velocity” →

Homemade Omnidirectional Speakers In A Unique Enclosure

September 11, 2014 by 36 Comments

While studying acoustics in college (university for non-Americans), [Nick] had a great idea for an omnidirectional speaker. Some models available for purchase have a single speaker with a channel to route the sound in all directions, but [Nick] decided that a dodecahedron enclosure with 12 speakers would be a much more impressive route.

To accommodate the array of speakers, the enclosure needs twelve pentagons with a 58.3 degree bevel so that they fit together in a ball shape. After thinking about all of the complicated ways he could get this angle cut into the wood pentagons, he ended up using a simple circular saw!

Once the enclosure was painted [Nick] started wiring up the speakers. The equivalent impedance of the array of 8-ohm speakers works out to just around 10 ohms, which is easily driven by most amplifiers. The whole thing was hung from a custom-made galvanized pipe (all the weight adds up to about 15 kilograms, or 33 pounds for Americans, so the rig needed to be sturdy). We’ve featured other unique speaker builds, but this is the first 12-speaker omnidirectional speaker we’ve seen. [Nick] is happy to report that the speakers sound great, too!

Fail Of The Week: This Inanimate Titanium Rod

September 11, 2014 by 69 Comments

You saw [Chris] cast aluminium on the cheap using Kinetic Sand a few weeks ago, didn’t you? He recently got his meaty hands on some titanium through the magic of modern transactional methods and was bowled over by its strength, hardness, and poor heat transfer.

He thought he would cast it into a nice, strong bottle opener. As you can probably guess, that didn’t go so well. First off, it wasn’t easy to saw through the thin rod. Once he did get it split in twain, it was surprisingly cool to the touch except at the tip. This is nasty foreshadowing, no?

[Chris] takes a moment to help us absorb the gravity of what he’s about to do, which of course is to send several hundred amps through that poor rod using a DC arc welder. Special precautions are necessary due to the reaction between oxygen and heated titanium. His trusty graphite crucible is grounded to the bottom of a big aluminium tub, and a cozy blanket of argon from a TIG welder will shield the titanium from burnination.

Well . . . the titanium didn’t melt. Furthermore, the crucible is toast. On the up side, vise-enabled cross-sectional examination of the crucible proved that there was still gold in them there walls.

Do you have any (constructive, on-topic) suggestions for [Chris]? Let him know below.

Continue reading “Fail Of The Week: This Inanimate Titanium Rod” →

file server

Antique Case For Custom File Server

September 11, 2014 by 46 Comments

Michigan Tech was throwing out a bunch of old electronic equipment, and [Evan] snagged quite a gem: a UHF signal generator built by Hewlett Packard circa 1955. He stripped all of the remaining electronics out of the case, but kept the slide-out trays and the front instrument panel to create this antique-looking file server.

The bottom tray was where the bulk of the electronics were housed, and since widespread adaptation of transistors for electronics wasn’t common at the time (the first silicon transistor wasn’t made until 1954), the original equipment was all vacuum tubes. This meant that there was just enough space for a motherboard, heat sink, and a couple of power supplies.

The hard drives are held in custom housings in the top portion of the case. The real magic, however, is with the front display panel. [Evan] was able to use the original meters, including a display for “megacycles” which is still technically accurate. The meters are driven by a USB-to-serial cable and a python script that runs on the server.

The antique case is a great touch for this robust file server. Make sure to put it in a prominent place, like next to your antique tube radio.