Dr.Duino’s Stem Class- Controlling 90 LED’s via Bluetooth!

STEM is to Engineering as “the force” is to a Jedi. From a very young age I knew I wanted to be an engineer. I was fortunate to have my very own personal Yoda who also happened to be my uncle. He trained my young mind in the ways of the engineering force by harnessing the principles contained within STEM. Fast forward to today where I am an engineer and business owner. As yoda would say, “Time it is to teach while the force is strong .” Ok, enough with the star wars humor. I have finally reached a point where I could pursue my passion for engineering by teaching STEM via Arduino to the next generation. I was fortunate enough to find three young minds who were naturally curious about electronics. We currently meet once per week for several hours where I teach using real world projects. I will uphold my commitment to influence them in the ways of the engineering force for as long as they wish. Eventually, I hope that they will also pay it forward.

 Allow me to introduce the team (now dubbed the Embedded Engineers Club or E^2C for short), from left to right, Sean F., Steve C., Mason B.

E2C Team

Immediately upon starting my STEM class, I wanted to take a different approach to teaching. Thinking back to my early school years, the way science and math was taught, while interesting was difficult to correlate with the real world. So, I vowed that I would teach in a more meaningful way; one which would demonstrate a clear relationship between STEM and reality.

The team is naturally curious and infatuated with music and lights (come on, what engineer isn’t?) So we started to create something so unbelievably cool, the fonze would be jealous. Okay, I’m dating myself here… In this blog, I’d like to share with you our project which I hope you will find as amazing as my students and I do. Without further ado, meet the “BlinkyBlinkyPlate”.

Blinky Blinky Plate

Blinky Blinky Plate consists of a custom 3D printed name plate made on my Replicator 1 from maker bot. Below is the 3D rendering of one of the plates.

3D Rendering Blinky Blinky Plate

It was printed on this guy… yeah… pretty old but seriously cool. Ive got over 400 hours of print time and she is still ticking! Job well done Makerbot team!

MakerBot Replicator 1

 Here is what it looked like fresh out of the printer.

3D Printed Name plates

Next we need a way to mount 30, tri-colored LED’s to the name plate. So we created this tiny adapter board which breaks out the individual legs of the LED’s to a 4 pin header. One for Red, Green, Blue and power.

Custom RGB breakout board

 LED

After several weeks of wiring and what felt like 400 pounds of hot glue, we arrived at this menagerie of awesomeness. Which by the way, what self-respecting engineer doesn’t make prototypes without a glue gun I ask you?

Blinky Blinky Plate wiring complete

We then needed to control all 90 Led’s from something simple. Adafruit to the rescue! This little board can control up to 24 LED’s from one tiny board. Best part is, they can be daisy chained provided that you have enough power. Each nameplate needed 4 of these little buggers. You can find the code for controlling this guy here.

Adafruit 24-Channel 12-bit PWM LED Driver - SPI Interface - TLC5947

 We then needed to write some initial code which would control our Arduino Uno. Once we had that we needed to run our first test. Check this out, came out pretty good huh?

 Initial Testing

Next we wanted to be able to change modes based on some button presses and pots but the over engineering genie began to visit us. So bluetooth control was suddenly a must. We used the JY-MCU which was so easy to use from Amazon. Just be careful when using it, the RX line is not 5V tolerant so a divider network is needed or you will let the smoke out of this little guy (aka blow it up).

JY-MCU Bluetooth Module

Next we downloaded S2 terminal from the google app store to communicate with our Bluetooth module and sent various commands to get into our different modes. Its a great free app!

Now that we had the ability to talk to our Blinky Blinky Plate, we began to make various modes. All Red, All Blue, All Green, All white (ouch giant power draw), Chase and last but certainly not least, the pièce de résistance audio analyzer mode! Again from Amazon!

Audio Analyzer Chip

Now, this guys is seriously cool. In hardware it separates the various frequencies into seven different comma delimited values. E.g. Bass, mid-range, treble and everything in between. We assigned Red to bass, green to midrange and blue to treble. The outcome was nothing short of magical wizardry encased in plastic. Check out this video of Blinky Blinky Plate dancing to "The Hills". TURN UP YOUR VOLUME!

 We started this project in March of 2015 and “completed it” around December of 2015 and are still tinkering with it as it’s a great learning platform. Stay tuned for our next project, it may even turn into another kickstarter!

Arduino is the perfect platform to get started in electronics, it's simple, affordable and did I mention simple? I specifically chose Arduino when I started thinking about offering a STEM class as all of the other professional tools out there are a real challenge to use just to get a light to blink. You know who you are :)

Not with Arduino though. If you are new to electronics and really want to get your feet wet, get yourself a Arduino uno and a Dr.Duino shield and BAM you are off and coding without messing with the complications of hardware and firmware issues. Just focus on writing code to make your very own lights blink. More information on the Dr.Duino board can be found here.

Dr.Duino Arduino Breakout and Learning Kit


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