Portable LED Flicker

Researchers at the Stanford VISTA Lab have been studying human color perception using fMRI scanning and their own LED Flicker technology. Using the LED Flicker, they can examine which colors humans cannot consciously perceive but still actively detect within the brain.

For the purpose of demonstrating their work at future conference events, I was asked to create a portable LED Flicker. After conceptualizing possible solutions, I constructed the device with introductory EE knowledge (drafting, resistance calculation, soldering) ontop an Arduino Mega. I also included a comprehensive tutorial to recreate my setup in the Wiki report below.

For a working demo, please click here.
For more information, please see my Wiki report.
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The current LED flicker device is much too bulky to travel around with as is. So, I conceptualized the idea of a flashlight carrier. Some ideas included fiber optics and directed light beams.

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I sketched out circuitry schematics and performed basic EE calculations. These served as guides to obtain the correct resistors for each LED and visualize the device's construction.

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I assembled the portable flicker on top of an Arduino Mega base. I soldered the resistors and LEDs to a shield and added heat shrinking wraps to prevent the wires from crossing paths.

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Here, the LEDs are shown with semi-directed beams. The colors mix but not sufficiently for an optimal blend of colors. I needed a better diffuser to achieve my desired results.

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I researched several diffusing materials, including sanding plastic services, alabaster, and even hot glue. I considered using a plastic spray cap as a first filter and received moderate results.

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To improve the color blending capability even more, so I consulted with the researchers I was helping. They suggested using a special difusing film, which is shown above.

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I also drafted an improved iteration with a larger case and more LEDs. My contribution provides the means to create a powerful portable LED flicker, leaving room for researchers to springboard.