Day: December 14, 2015

Thomas Midgley, GM, And The Dark Side Of Progress

December 14, 2015 by 75 Comments

Scientific improvements that create industries and save millions of lives often come at a price that isn’t revealed until much later. Leaded gasoline helped the automobile industry take off and synthesized Freon extended the lifespan of lifesaving vaccines, but they took an incredible toll on the environment.

Both were invented in the early 20th century by Thomas Midgley, Jr. After graduating from Cornell in 1911 with a degree in mechanical engineering, he worked briefly for National Cash Register where inventor Charles Kettering had just created the first electronic till. In 1916, Midgley started working for Kettering at Dayton Metal Products Company, which soon became the research division of General Motors.

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Seeing Around Corners With Frickin’ Lasers

December 14, 2015 by 31 Comments

Researchers at the University of Edinburgh and Heriot-Watt University have created a sensor that can see around corners using lasers, high speed cameras, and some intense data processing. They can essentially turn a laser light source into a virtual mirror to look through.

Led by [Genevieve Gariepy], the team has been able to prove their research in a lab setting, and are now trying to refine it to work in the real world. While the animated image above makes the system seem rather simple, the tech behind it makes our heads hurt.

The timing measurement alone for the laser light to bounce off the hidden object and be reflected to where the camera can see it needs to be accurate down to the 500 billionth of a second (500 nanoseconds). Five hundred billionths.

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Polyphonic FM Synthesizer Uses ARM

December 14, 2015 by 13 Comments

There seems to be a direct correlation between musicians and people who can program. Even programmers who don’t play an instrument often have a profound appreciation of music and so we see quite a few musical projects pop up. [Ihsan Kehribar’s] latest project is a good example. He married an STM32F031 ARM development board, an audio codec, and a simple op amp filter to make a playable MIDI instrument. Of course, it is hard to appreciate a music project from a picture, but if you want to listen to the results, there’s always Soundcloud.

He’d started the project using an 8-bit micro, but ran into some limitations. He switched to an STM32F031, which is a low-end ARM Cortex M0 chip. [Ihsan] mentions that he could have used the DSP instructions built into larger ARM chips, but he wanted to keep the project done on minimal hardware. The audio CODEC chip is from Cirrus Logic (a WM8524), and it produces two output channels at 192 kHz. As an unexpected benefit, the CODEC uses a charge pump to generate a negative voltage (much like a MAX232 does) and [Ihsan] was able to tap that voltage to provide the op-amps in the audio filter with a negative supply rail.

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