Since Cameron Hoerig is an engineering student at the University of Cincinnati, the idea of building a typical beer pong table was out of the question. "I'm an electrical engineering student, so I should have a table that stands out," says Hoerig.
He built an interactive table. On either end of the table - where the cups stand - there are 10 LED rings composed of eight LEDs each. In the middle of each ring there's a photocell. The Ping-Pong ball triggers the sensors and the gadget's software rotates the LEDs, giving the illusion of a light spinning around the cup.
It's impossible to read the documentation but I'm responding to your problem with inconsistent linearity of photocells. Yes, photocells are imprecise and non-linear. Much of the voltage appears across the limiting resistor. Consider putting a transistor as a constant current source in series with photocells, eliminating the resistor. The voltage across the transistor will be a consistent two diode drops. That way, all the voltage change appears across the photocell. I hope I have understood your problem.
Two different shape-shifting polymers have been announced from two different universities: Wyss Institute at Harvard University and Zhejiang University in eastern China. Both of them change their shapes when immersed in water, and the one from Wyss Institute was made with 3D-printing techniques.
When you think of the DARPA Robotics Challenge, you may imagine complex humanoid contraptions made of metal and wires that move like a Terminator Series T-90. But what actually happened at the much-vaunted event was something just a bit different.
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