The echo box performs exactly as its name implies. If you tap out a rhythm on the lid, it will tap the same thing back to you. Except it isn’t tapping to make the sound, but vibrating.
The concept is similar to the Knock Block. In that hack, a piezo element detected a rapping on the wooden enclosure and repeated the rhythm by striking the lid with a solenoid. This iteration also uses a piezo element as the sensor. In the image above you can see a segment of PVC pipe in the upper corner. That houses the element, sandwiched between two pieces of wine bottle cork. That cork just touches the lid of the box, transferring the vibrations to the element.
The sound is created by a motor with an offset weight on its spindle. When the motor spins, it causes vibrations. The enclosure is one wood box inside of another, so the vibrating motor cause the inner box to shake against the outer one to make noise. Hear it for yourself in the clip after the break.
Looking at the size of this bristlebot the first thing we wondered is where’s the battery? All we know is that it’s a rechargeable NiMH and it must be hiding under that tiny circuit board. But [Naghi Sotoudeh] didn’t just build a mindless device that jiggles its way across a table. This vibrating robot is controllable with an infrared remote control. It uses an ATtiny45 microcontroller to monitor an IR receiver for user input. An RC5 compatible television remote control lets you send commands, driving the tiny form factor in more ways than we thought possible. Check out the video after the break to see how well the two vibrating motors work at propelling the device. They’re driven using a PWM signal with makes for better control, but it doesn’t look like there’s any protection circuitry which raises concern for the longevity of the uC.
This concept robot uses angular momentum to roll around. You can see that on either end of the robot there are two discs which have been cut on one side to make them off-balance. For locomotion, two DC motors spin the outer discs which are not in contact with the floor. This spinning action exerts a force in the opposite direction on the body of the vehicle, causing it to move.
It’s not a perfect system and there is one major flaw with using this system. When the forces have equalized acceleration will stop and it will eventually come to a standstill. You can’t just stop spinning the motors because that will act as a braking mechanism. But still, it’s a concept we haven’t seen before and we love the experimentation that’s happening here. Take a look at the test footage after the break and don’t hesitate to let us know if this starts causing light bulbs to flip on above your head.
The Winduino II uses fins to pick up the movement of the wind and translate it into music. Each fin is attached to the main body using a piezo vibration sensor. The signals are processed by an Arduino housed inside and the resulting data makes its way to a computer via a Bluetooth connection to facilitate the use of Max/MSP for the audio processing. Included in the design is an array of solar panels used to keep the battery for the device charged up. Hear and see this creative piece after the break.
The Formica project was our favorite presentation at 25C3. The goal is to build open source swarm robots as cheaply as possible. The team ended up building 25 robots in an assembly line fashion. With enough lead time, the price could get as low as £15 each. Each bot has two direct drive cellphone vibration motors with tiny neoprene wheels. They’re controlled by an MSP430 microcontroller. The only really specialized chip is a charge controller so the bots can charge without any intervention. They have copper skis on the front that touch the ground plane plus antennas to contact Vcc. On top of the bot are three IR detectors for both navigation and for transferring firmware updates between bots. A reflective sensor is on the underside for detecting “food”. It looks like a great design and any easy way for anyone to start researching swarm robotics.
In our Dev Phone 1 excitement last week, we somehow overlooked phoneWreck’s teardown of the T-Mobile G1. The complex slider mechanism is certainly worth looking out. One of the major oddities they point out is the inclusion of two vibration motors. One is mounted next to the SIM on the mainboard. While the other is mounted in the frame next to the earpiece. We wonder what was gained/solved by using two. The phone also includes a digital compass module. We’d like a more detailed explanation of how the Xilinx CPLD is used. From this article in 2006, it seems HTC uses them to generate custom clock signals and switching off devices for power management.
People tend not to think about the non-Newtonian properties of foodstuffs, but we’re glad at least one person did. When it comes to cornstarch, it’s indeterminate viscosity when mixed with water made it the perfect solution for a pretty neat trick: making a liquid move in reaction to a subwoofer. The unique motion can be attributed to the physical properties of the solution: when enough force is applied quickly, it acts as a solid. Otherwise, it flows like a liquid. The erratic bouncing of the sound waves combined with a little tactile manipulation create varying degrees and speeds of applied pressure, which in turn create a mass of flowing shapes that almost appear to be alive.
We’ve covered weird fluids before, but this is perhaps most similar to SnOil, a game that uses ferrofluids to achieve a similar result. SnOil, however, does not depend of vibrations to create shapes in the fluid, it uses small electromagnets and magnetically charges liquid instead. We love the ordered appearance of the SnOil unit, but the chaotic motion of the cornstarch and it’s non-Newtonian properties make it appear almost otherworldly. We wonder how ferrofluids would react in a situation similar to the cornstarch above, since it would respond to both the vibration and the voice coil’s magnetic field.