About Lenore

Co-founder of Evil Mad Scientist Laboratories

Three Fives in IEEE Spectrum

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Our Three Fives Kit was featured in this month’s IEEE Spectrum. From the article:

Just as DNA models, star maps, and periodic tables serve as reminders of fundamentals that can get obscured by day-to-day minutiae, so too the Three Fives kit is a reminder that even the most complex digital processor is still at its heart just a collection of very simple components.

You can read the full article and see pictures of it in use in a sample circuit over at IEEE Spectrum.

Cool Wearable Electronics

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Mascot costumes are often hot and sweaty, and mascots are expected to enthusiastically energize their teams. At FIRST robotics competitions, there are also traditions of dance parties during delays caused by technical difficulties, leading to even more activity in a warm, heavy costume than would normally be expected.

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Cardinalbotics, an FRC team from San Francisco, made a mascot costume using an application of wearable electronics I had not considered before: cooling fans. The cardinal head was made of fabric sewn over shaped foam, with fans on the sides to keep everything cool inside.

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The fans were wired up to an on/off switch and adjustment pot which were hidden in a velcro compartment in the back of the head.

From the Mailbag: on STEAM Education

Evil Mad Scientist STEAM T-shirt
Trevor wrote in:

I’ve probably said it a million times, but I don’t think I’ve told you guys. You’re amazing. When it’s time for a new project I jump over to EMSL first. I use your projects to demonstrate a lot of STEAM principles at my Makerspace, and proudly wear my EMSL STEAM shirt every Saturday morning when I’m teaching our Makerspace Cadets class. (It’s a fun sciencey/makey/artsy class for kids). Keep up the great work. :)

Thank you for the kind words, and for your dedication to your students!

Robots in the Central Valley

Rows of busy pits

Friday was a busy day in the pits at the Central Valley Regional FIRST Robotics Competition. The teams got their robots unpacked, inspected, and ran practice rounds prior to matches this weekend. We’re here with Fremont Robotics, and we’ll be taking pictures throughout the weekend and posting them (tagged by team number where identifiable) in this flickr set.

On the field

The challenge this year is fun to watch: the robots score goals with large exercise balls and earn extra points for passing to team members and throwing the ball over a beam. The event is free to attend and open to the public, so if you’re near Madera, California this weekend, we’d love to see you here!

Larson Scanner modding

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Anton wrote in to ask:

I want to purchase your Larson Scanner kit but need to be able to run it from household current … is there a converter that you would recommend?

Since the Larson Scanner normally runs from 3 V DC, a regulated 3 V power supply can be hooked up in place of the 2xAA battery box. However, 5 V power supplies (like this one) are much more common, and the circuit can be run from 5 V with only minor changes. if you replace the nine 16 ohm resistors in the Larson Scanner kit with 120 – 150 ohm resistors, you can power it from 5 V directly.

Another related question we occasionally get is how to run the Larson Scanner with green LEDs. (Note: by green, we mean “pure” green LEDs which have a forward voltage of about 3 V. Older style yellow-green LEDs with a forward voltage of ~2 V can be used as drop-in replacements for the red ones.) 

If running off of battery will work for you, this is an even simpler change: merely replace the 3 V battery holder with a 4.5 V one, such as a 3xAA. It is a happy coincidence that the circuit can run with red LEDs at 3 V or green LEDs at 4.5 V using the same 16 ohm resistor value. So how about running a green Larson Scanner from a 5 V power supply? Replace the nine 16 ohm resistors with 39 ohm resistors and you should be good to go.

You can find the documentation for the Larson Scanner and more stories about modding it on our wiki. We’d love to hear about any mods you do to the Larson Scanner in the comments or see pictures in the flickr pool.