# LED spectroscopy

I’m working on a project that will include using LEDs as light sensors, and one of the first tasks is to learn a bit more about the wavelengths of light that are emitted by an array of LEDs. Since I’ve recently created a Mathematica interface to an Ocean Optics spectrometer (on a Raspberry Pi, naturally), the first task was pretty straightforward.

# Happy Holidays – from Mandy

I am teaching Mandy to sing (sort of).  Here’s Mandy playing along to Carol of the Bells in what may be the worlds “first” Periodic Table spectrum visualizer.  Now, before we blow up the Twitter sphere with allegations that Mandy belongs on the Top Ten List of Most Infamous Lip Syncing incidents, I’m not claiming that this is live.  Mandy wasn’t designed to do real-time spectrum analysis (she’s a Periodic Table, after all) but I wanted to see if some geeky visualizations would be possible.  So, I created my own version of Carol of the Bells (written in Sonic-Pi) and then analyzed the audio file using Mathematica, which has a neat function, SpectrogramArray[], that provides easy access to the frequencies in an audio file.  I then binned the frequencies into 118 buckets – one for each element on the periodic table, and converted the intensities into colors (blue for high amplitude, red for low amplitude).  I probably should have thought a bit more about which elements should display which frequencies, but time was running short so I simply made the heavier elements have the lower frequencies.  In any case – enjoy.

# Mandy: The Table Revealed

Clearly it’s that time of the year when I have a boat-load of grading to do.  Otherwise, I wouldn’t be procrastinating with posts to my website.

Here’s a video of how Mandy – The Bright Periodic Table looks on the inside, and a demonstration of how she responds to a user’s commands.

# Mandy: The periodic table (teaser)

About six months ago, I started working on a project I like to call my piece de resistance. It combines a number of maker skills that I’ve learned over the past few years.  I call her Mandy, and she’s a laser-cut periodic table that has a bunch of three-color LEDS, an Arduino that controls the individually addressable LEDs, and a Raspberry Pi that stores information about the elements.  To make it stand out from being “just another bright periodic table”, I added a voice activation component, so Mandy is able to display different periodic trends at your verbal command!

I’m getting ready to move to a different part of the country, so I do not have time to provide more information about Mandy.  In the meanwhile, I created a teaser-trailer for your (OK, my) personal enjoyment.

# Microwolf – running Mathematica on a Pi Zero

Wolfram’s Mathematica can run on a \$5 Raspberry Pi zero. While it may be painfully slow, it does open up opportunities to use Mathematica in low-power, remote-sensing applications. This blog post is a first in a series highlighting the design challenges I’ve encountered (and in some cases overcome) building Mathematica on Pi (MoP) devices. (Hey, I think I just created a new acronym.)