What separates a 2d image from a 3d image? We only see the world in 2d dimensions, so how do we know the difference between 2d and 3d. Our eyes observe objects from two different perspectives, each eye getting its own image. Furthermore, when you move your head, you experience parallax. In order to recreate this experience using an LCD monitor, each observer must see a different image. One way of doing this is to do the reverse of a pinhole camera and show each observer a different image. This project was my first (crude) step in exploring this area.
The first version of this display is a whopping 6 pixels by 6 pixels. Perfect for watching Iron Man in HD. The restriction in resolution is due to imperfections in the alignment of the holes in the filter, the low-light intensity by the LCD backlight, and the low pixel density of the LCD.
Improving any (or all of these) would allow for more resolution in the screen.My goal is to eventually make a 240x320 version that can handle up to 36 independent views (6 lateral, 6 vertical). I'm still a far way off.
The filter is made by putting evenly spaced holes (using graph paper as a guide) into black construction paper. This is placed over a cardboard box which situates the filter a fixed distance from the LCD.
Here's a video of the display in action:
Ever had trouble waking up in the morning? Ever unconsciously turned off your own alarms?
Never have this problem again with PillowPal! Your friends now have complete control over when you wake up. Isn't that great? PillowPal allows your facebook friends to access your pillow online and turn on lights and music to wake you up in the morning.
PillowPal is an attachment for your phone. It communicates with your phone through the audio port, so it works with almost every phone. The brains of the pillow are a picaxe microcontroller and a set of 32 RGB addressable LED's which will blink different colors when its time to wake up.
This hack was made by Jesika Haria, Prabhav Jain, and Geza Kovacs for HackMIT. We made it to the finals! But didn't win :(
Imagine diving into another world without ever having to leave your desk. The immersion project turns your computer into a window to another world. You can now interact with google streetview panoramas by moving your head. This website uses the newest features of HTML5 and javascript head-tracking libraries to provide you an amazing experience using just your webcam for input.
When you hear music, your foot starts tapping. What if your clothes interacted with the music around you! The wrist-wave is a battery operated wearable LED display which changes patterns according to the music around you! Great for dance clubs!
Technical details:
32 RGB LED (from addressable LED strips)
PICAXE for control Condenser microphone for detecting music
There are 110 million active landmines scattered across 70 countries worldwide. Many of these mines have plastic casings, making them very hard to detect using conventional metal-detectors. For my capstone project at Tufts University, I developed a low-cost prototype acoustic land-mine detector. Here is a summary music video. More project details are below:
Theory:
Buried landmines can be hard to detect, especially if they have been buried for a long time. When vibrated. however, landmines interact dynamically with the soil around them. The detector works by transmitting two sound tones (two frequencies) and records the sound that bounces back. The detector analyzes the characteristic response of the landmine-dirt system and then determines whether a landmine is buried.
Two frequencies are transmitted into the ground. The detection algorithm detects the non-linear combination of these two frequencies. These non-linear (non-harmonic) peaks in the spectrum of the response is caused by the landmine bouncing against its environment.
On top you can see that when there is no landmine, only the two transmitted frequencies are received. Below you can see the ideal reaction when there is a landmine buried.
Initial Setup:
Initial setup using an old receiver amplifier, speaker, and microphone. Objects tested were plastic pvc-endcaps (2-4 inches in diameter).
Prototype and testing:
The portable prototype uses 2-9V batteries to run the amplifier and transducer and a laptop running matlab for signal processing. Testing was done at a nearby Airforce National Guard base using inert replica landmines.
Results:
The detector was able to discriminate areas with buried objects from those without buried objects with a probability of detection of 70%. The sample size used was too small to truly tell the functionality of the detector, however the initial results show a false alarm rate lower than most metal-based detectors and a probability of detection which is also comparable. Note that there is always a trade-off between probability of detection and false alarm rate.
Conclusion:
This was a great project to learn about the concept of signal-detection. In the future I woudl like to validate the portable design by testing further, generating a full Receiver Operating Characterisc (ROC) curve, and implement an smart-phone app to perform the signal processing (so the whole rig will be more portable).
Tuesday, September 4, 2012
Hey funky people!
This is a blog to keep track of and showcase the work I'm doing. It's not exhaustive but will include some of the highlights. Let me know if you have any questions or if you want me to elaborate on anything. In most cases I'd be more than happy to share my technique/design.
We'll start with this SUPER SICK and INFINITELY EXTREME function generator by myself, Ryan Hofstetter, and Vinh Pham:
Specs:
+/- 15V waveform generator
Pulse (square), Sawtooth, Sin-Wave
Amplitude control
Frequency control
Schmitt-Trigger Oscillator
See-through design (so you can see the gnomes working inside)
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