At Interaction 2011, a research group from Osaka University exhibited a fog display that enables multi-viewpoint observation. [via]
“Ordinary fog displays use a single projector with fog on a flat surface, but this display uses three projectors, each showing a different picture. So when the observer moves around the fog, they get a three-dimensional view.”
3D Volumetric Fog Display – [Link]
Josh wanted to wander the streets of Chicago on his bike while ensuring he was heading in the general direction of his destination. He therefore created the MapBag, a LilyPad Arduino-based “proprioceptive augmentation device.” Here’s how it works: [via]
The MapBag contains a small microcontroller, a GPS chipset, and a series of 8 vibration motors sewn into the bag. The microcontroller constantly evaluates the wearer’s current heading and the location of magnetic North, or the relative location of a user-defined waypoint (such as home). The microcontroller informs the wearer of compass information through the vibration motors, basically allowing you to read a compass with your body.
After using the MapBag for a few weeks, the slight pulses used to convey heading information have become second nature. Most importantly, I no longer find myself using street signs or depending on landmarks to discern my position in the city’s grid.
GPS Messenger Bag Bestows Bikers with a Better Sense of Direction – [Link]
Gratuitous device tracks door position with laser-printed linear quadrature encoder; commands servo to aim projector at door. Projector is a thrift store 50mm camera lens, teensy scrap of laser-printed transparency, and a 1W Cree LED. Electronics is an Atmega 8 with two Futurlec reflective IR sensors and PWM output to the servo. Source code in R-ULAV tree, available at http://rocket.jonh.net
Dynamic tracking door nameplate projector - [Link]
Make an electronic circuit that will trigger camera flashes in sync with a thunder soundtrack (great for Halloween)! The camera flashes are salvaged from old, broken cameras. When used along with lamps plugged into a color organ circuit, it makes a very effective lightning effect.
Lightning effect using camera flash units – [Link]
Nice project from Petar , he send me some photos of his UV Box. This UV LED Exposure Box was published in the magazine Emiter, and here’s what the author says on this project.
My UV box contains 54 ultraviolet 5mm LED distributed in a matrix of 9X6 leds. The box can enlighten board with maximum dimension of 12X18cm. Built-in digital timer allows programming of the desired time for lighting.
Keep away your lights from direct UV light from box. Wavelength of the LED is the same with the sensitivity of the UV spectrum of photo spray Positive 20.
UV LED PCB Exposure Box – [Link]
Circuit of stereo FM transmitter of of high quality using integrated circuit ba1404 for mp3, mp4, ipod, computer, radio of the car. Transmit of your equipment of portable audio for the radio of your car, transmitters of fm of low potency are the ideal for transmission wireless of audio sign for fm receivers. Mainly in that case that is treated of transmitter of FM stereo with ba1404. The heart of that circuit is the circuit integrated ba1404, that is a mini fm transmitter, that already counts with the necessary internal circuits for transmission in fm. just being necessary to increase some components discman or any other audio source turning the wireless. If you already set up other transmitters of transistorized fm it will see that when setting up that with having integrated BA1404, that the quality of the sound and the frequency stability is excellent. Besides the but it presents easy assembly.
Stereo FM Transmitter with BA1404 – [Link]
This amplifier is based on the PA100 parallel amplifier detailed in National Semiconductor’s application note – AN1192.
Since my DIY speaker is 4-ohm and somewhat difficult to drive, I want to have a more powerful amplifier to match with it. Therefore I designed this amplifier which uses two LM3886 per channel, in parallel circuit. This amp can deliver about 50W into a 8-ohm speaker and 100W into a 4-ohm speaker. This is a stereo amplifier and therefore 4 LM3886s are used.
100W LM3886 Parallel Stereo Power Amplifier – [Link]
Eric Hsieh and Luke Thomas writes:
Every group wants their final project to be something that will be remembered long after they’re gone. Some do highly sophisticated and complex projects that entail upwards of a hundred hours to complete. Yet others go out of their way to develop something ‘cool’ and ‘fun’. Luke and I decided that we wanted to be in this second category, because developing something that’s ‘cool’ would also be fun to do. So in deciding what to design we tried to think of something that would catch the attention of the people in the lab. The easiest way of doing this is to create something that would make noise or play music so everyone in the lab could enjoy it. Realizing this would be the best way to go, we decided to create a synthesizer that could record and playback notes, ‘teach’ the user how to play a simple melody, and also play some prerecorded tunes. After all, don’t you think being remembered as the group that played back the Imperial March theme from Star Wars is cooler than a paper tape reader? (no offense to those groups doing paper tape readers)
Sine Wave Synthesizer – [Link]
Precision circuit monitors negative-supply threshold: [via]
Using an IC (MAX971) that includes an open-drain comparator and a precision 1% voltage reference, this circuit monitors the magnitude of a negative supply voltage and provides a digital warning of fault conditions. To monitor multiple negative voltages, use the MAX974, which includes four comparators.
App note: Monitor negative power supplies – [Link]
Microchip’s MCP79411 general purpose I2C™Compatible real-time clock/calendar (RTCC) is highly integrated with nonvolatile memory and advanced features including a battery switchover circuit for backup power, a timestamp to log power failures and digital trimming for accuracy. It can use a low-cost 32.768 kHz crystal or other clock source and the chip operates over a supply range of 1.8 to 5.5 volts. [via]
MCP7941X I2C RTCC with EEPROM, SRAM, Unique ID and Battery Switchover – [Link]