Preheat alarm added to a basic kitchen oven

March 7, 2012 By Leave a Comment

[Justin] didn’t want to keep checking if the ‘oven heating’ indicator light had gone off before popping his unbaked edibles into the oven. Many models offer a buzzer to let you know when the chosen temp is reached, but for folks who own a basic oven model there’s just a light that tells when the heating element is getting juice. Not to worry, he plied his circuit design skills and built a buzzer to alert him when the oven’s ready.

It only took a few components to accomplish the task. [Justin] uses a pair of NPN transistors triggered by a photoresistor. One transistor is responsible for switching on the buzzer, the other transistor is driven by the photoresistor and controls the base of its companion transistor (see the schematic for a better understanding).

He designed and etched a small PCB to host all the parts. As you can see above, it mounts over the indicator light and is powered by a 9V battery. There’s an on/off switch to the right so the buzzer doesn’t keep triggering while cooking, and a potentiometer allows him to fine-tune the photoresistor sensitivity.

Filed Under: cooking hacks Tagged With: , , , , ,

Adding a lot of twinkle to this rebar sculpture

March 7, 2012 By Leave a Comment

Blinky lights have a way of attracting attention and that’s exactly what the members of the Maui Makers hackerspace were shooting for. The sculpture above is the logo for the Source festival, a Burning Man inspired music gathering in the Aloha state. For this year’s festival they went crazy, installing twelve meters of RGB LED strip controlled by seven Arduino boards.

The goal was to make the twelve-foot tall sculpture into a lighted interactive showpiece. In addition to the LEDs it includes a microphone, capacitance sensors, Bluetooth connectivity, and a piezo speaker. There’s one Arduino to rule them all, with another Teensy controller to drive an LCD display in the control box, and five Teensy boards to address the LED strips. They grabbed [Bill Porter’s] Easy Transfer library to facilitate communication between the microcontrollers (his libraries are becoming popular, we just saw his mp3 shield library used in another project on Tuesday).

The code which drives the LED animations is based on some Adafruit examples. We really enjoy the waving flag effect seen in the clip after the break.

[Read more…]

Filed Under: Hackerspaces, led hacks Tagged With: , , , ,

Vintage VT100 terminal computing…with a Beaglebone

March 7, 2012 By Leave a Comment

decbox

A cool little project came our way, which we thought might be of interest to some of you vintage computer buffs. [Joerg Hoppe] wrote in to share a DEC VT100 terminal he resurrected in a novel fashion.

His “DECBox” system was created with a Beaglebone, which he uses to run a wide array of PDP11/VAX terminal emulators, thanks to the SIMH project. [Joerg] constructed an expansion shield for the Beaglebone that provides several UART connections, enabling him to connect it to his DEC terminal over a serial interface. Since he added several serial plugs to the Beaglebone, he can even run multiple emulator installations in parallel on different terminals without too much trouble.

[Joerg’s] efforts are mainly for a vintage computer display he is constructing, but setting up such a system of your own should be no problem. If you happen to have one (or more) of these boxes sitting around collecting dust, this would be an easy way to get them all up and running without bulky external hardware, since the Beaglebone tucks nicely into the rear expansion slot on a VT100.

Be sure to check out his site for more details on how his DECBox software package works as well as for more pictures of vintage terminal goodness.

Filed Under: classic hacks Tagged With: , , , , , , ,

Six foot speaker shakes buildings to their foundation

March 7, 2012 By Leave a Comment

In the first scene of Back to the Future, [Marty McFly] visits the unoccupied laboratory of [Doc Brown]. Seeing an 8-foot-tall speaker connected to a huge array of amplifiers, [Marty] immediately turns on the amps, plugs in an electric guitar, and promptly destroys the amps and speaker while being thrown across the room. This scene must have been a huge inspiration to [Dan] and [Kyle]; they decided to replicate this gigantic speaker for the 2011 UW-Madison  Engineering Expo.

A speaker is a remarkably simple device – they’re usually just a coil of wire, a set of magnets on an iron frame, and a cone. [Dan] and [Kyle] wound hundreds of feet of copper wire around a fiberglass frame for the voice coil, used 8 and 10-inch steel pipe to secure the magnets, and pop riveted two sheets of polycarbonate together to form the cone. The result is a six-foot-diameter speaker in an 8x8x2 foot enclosure.

A speaker this size is only good for one thing: a ton of bass. The speaker can reliably reproduce frequencies from 5 Hz to 50 Hz, frequencies that are better felt than heard. There’s a video of the speaker in action after the break, but we’re pretty sure the best way to experience this insane device is in person.

[Read more…]

Filed Under: hardware Tagged With:

Sensor rig finds out if motorists are sharing the road with cyclists

March 7, 2012 By Leave a Comment

Apparently there’s some cause for concern when it comes to bikes and automobiles sharing the roads in Austin, Texas. [Christopher Stanton] wrote in to tell us there’s a law on the books now that requires motorists to give three feet of space when passing a cyclist. This is pretty difficult to enforce as there’s no solid proof like the radar gun provides when it comes to speed limits. The hardware above is seeking to help by collecting data on passing habits. It measures and records the distance of each vehicle that passes you while on the bike. The goal isn’t to ticket more drivers, it’s to collect statistical data that might help change dangerous driving habits.

As you can see, a front equipment rack hosts the hardware for easy installation on a bike. It has an arm that extends to the side the same distance as the handle bars. The HD camera with wide-angle lens is set to snap a photo which can be used to determine the bike and vehicle positions in the lanes, along with the distance readout from the sensor.

We’d certainly be interested in seeing the numbers for average passing clearance in a heavily traveled urban environment. Even with bike lanes, things can feel pretty tight on a busy day!

Filed Under: transportation hacks Tagged With: , , , ,

Foot-controlled mouse keeps your hands on the keyboard

March 7, 2012 By Leave a Comment

A bit of mechanical ingenuity makes building this foot-controlled mouse into a fun project. It consists of a platform which hosts one pedal for each foot. The right foot controls the movement of the cursor, and the left is responsible for the buttons.

The guts of a wireless mouse do most of the electrical work for this hack. You can see that the optical sensor is mounted on the front of the right foot pedal. A ball bearing combined with a hinge provides motion on two axes. This moves the sensor past a piece of curved foam made by covering a ball with plastic wrap then spraying foam insulation around it. The pedal on the left has four buttons actuated by moving the toes down, up, left, or right. There’s a centering mechanism for this pedal which uses a rubber band

One thing we wonder about here is whether there is a need to lift and re-center the mouse/cursor? There is also no scroll wheel. But those issues are just waiting for someone to pick up the project and make their own improvements.

Filed Under: peripherals hacks Tagged With: , ,
« Older Posts
Newer Posts »