FireHero: Raspberry Pi Controlled Pyrotechnics

December 22, 2012 by 24 Comments

Fire Hero 3

To put on a live pyrotechnic show at a music festival, [Chris] built the FireHero 3. The result is remotely controlled flames shooting up to 100 feet in the air.

The system is controlled by a Raspberry Pi and an Arduino. A server runs on the Pi and allows a remote computer to control the system. The Pi sends commands over serial to the Arduino, which switches solid state relays that actuate the valves.

There’s also some built in safety features: the system won’t boot unless you have the right key and RFID tag, and there are pressure transducers and temperature sensors to ensure the system is operating safely. A CO2 actuated valve can quickly stop fuel flow in an emergency.

Vaporized propane creates the fireballs. The vapor is created by heating the supply tank in a hot water bath. An accumulation tank stores the vapor and custom built manifolds distribute it to the various flame cannons. At each cannon, a silicon nitride hot surface igniter (HSI) is used to ignite the flames once the valve is opened.

After the break, watch a video the the FireHero making some flames.

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Building A Tornado In A Bottle

December 22, 2012 by 15 Comments

vortex-tornado-machine

Recreate the look of a tornado by building this water vortex art piece. The components that go into it are all very simple and can be found in your recycling bin with the exception of a motor and a way to drive it. The hard part is going to be getting to the point where you don’t have any leaks.

[Ixisuprflyixi] went with an empty salsa bottle to house the vortex. It’s a pleasant shape for the project since it’s both tall and narrow and it’s got a bit of a sexy curve to it. The base of the machine is a plastic bottle which looks like it might have been for Metamucil, but we’re not sure.  The important part is that it needs to be made from HDPE, as a portion of the container will be used to make the impeller. That’s the part that attaches to the motor shaft inside of the container. Give it a spin and you’ve got yourself a tornado in a bottle. See it in action after the jump.

This is a much quicker and easier version than the one we saw [Ben Krasnow] build. He ended up doing some repair work on the gasket that seals the motor shaft. It’s an interesting read if you are thinking of building one of these yourself.

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Adding Task Lighting Inside A Desk

December 21, 2012 by 32 Comments

storage-task-lighting

[Mahesh Venkitachalam] wanted to light up the dark recesses of his desk. What good is all that storage if you can’t see a darn thing in there? His solution was to add LED strips which turn on automatically when the door is opened.

The design is quite simple. A 2N2222 NPN transistor is responsible for connecting the ground rail of the LED strips mounted under each shelf. The base of that transistor is held high with a pull-up resistor. But a reed switch always connects the base to ground when the door is shut. Opening the door removes the magnet that keeps that reed switch closed. This allows current to flow from the pull-up to the base, connecting the ground rail to the LED strips and turning them on. You can see the video demo after the break.

One problem that we see with the design is that these are driven by a 9V battery. Over a long period of time that pull-up resistor will drain the cell. You can pick up a magnetic reed switch at the hardware or electronics store that is rated for 500 mA. If you can stay under that with the LED strips, and get one that is open when the magnet is present you will have zero power drain when the lights aren’t being used.

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Adding A Timer Feature To This Desk Lamp

December 21, 2012 by 18 Comments

timer-lamp

[Steven Mackaay] added a simple user interface that implements a shutoff timer for his desk lamp. His project log comes in two parts, the breadboarding and the actual implementation.

He wanted a few things out of the build. The first is an LED that would help him find the lamp in the dark. The second feature is a shutoff timer with different delay options. To get everything working he used a PIC microcontroller to drive a mechanical relay. That relay switches the mains power to the lamps. Now he uses one button to switch the lamp on and off. The other selects a shutoff timer of one, five, or thirty minutes. Power for the control circuitry is provided by the green wall wart PCB seen in the photo of the electronic guts.

This is a pretty general setup that could be applied to a lot of other mains switching applications. Just connect the logic hardware to some type of relay.

Webcam Eye-tracking Moves Robot-powered Skittles Candy

December 21, 2012 by 8 Comments

robot-powered-skittles

This is a great hack, and it’s an advertisement. We wish this were the norm when it comes to advertising because they’ve really got our number. Skittles enlisted a few engineers to build a web interface that moves robot-powered candies.

When we started looking into this we figured that a few robots were covered with over-sized cases that looked like Skittles. But that’s not it at all. What you see above is actually upside down. The top side of the white surface has one tiny wheeled robot for each candy. A magnet was embedded in each Skittle which holds it to the underside of the surface. The user interface was rolled out on a Facebook page. It uses a common webcam for eye tracking. When you move your eyes, the robot controlling your assigned candy moves in that direction. See for yourself in the cllip after the break.

So we say bravo Mars Inc. We love it that you decided to show off what’s behind to curtain. As with the Hyundai pixel wall, there’s a whole subset of people who might ignore the ad, but will spend a lot of time to find out how it was done.

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Making Graphene With A DVD Burner

December 21, 2012 by 64 Comments

A group of researchers have figured out how to produce graphene using a DVD drive. This discovery helps clear the path for mass production of the substance, which was discovered in the late 1980’s. More recently, the 2010 Nobel Prize for Physics was awarded to a team that produced two-dimensional graphene; a substance one just atom thick. One method of doing so used Scotch tape and is mentioned in the video after the break as a technique that works but is not feasible for large-scale production.

The process seen here starts with graphite oxide because it can be suspended in water. This allows a lab technician to evenly distribute the substance on a plastic surface. Note the use of optical discs. The second part of the process involves hitting the dried layer of graphite oxide with a laser. It just so happens that this can be done with a consumer DVD drive. The result is graphene that can be used in circuits and may have potential as a fantastic super-capacitor.

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Wooden Box Repeats Rhythm Used When Knocking On The Lid

December 21, 2012 by 10 Comments

knock-box-build

[Paul Mandel] just finished building this knock box project. It’s a familiar concept that uses a solenoid to tap on the side of the box. The Arduino driven setup monitors vibrations on the lid. When you knock on the box, it records the pattern and plays it back using the solenoid.

He was inspired by a knock-detecting door lock. Using that code as the starting point he implemented a system that takes input from a simple push button and echos back the rhythm using the Pin 13 LED on the Arduino board. This is a great way to start as it removes the complexity of driving a solenoid and monitoring a piezo element. After a bit of success he implemented each of those hardware modules one at a time. You can get a look at the final product in the clip after the break.

One of our favorite version of this project is still the knock block from several years back.

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