Sunday, October 26, 2014

Internet of Things Hackday Trip Report

Last week I attended the Internet-of-Things Hackfest at Minnetronix is the Twin Cities.

Dan McCreary working with a student on the Moving Rainbow Arduino Kit

Here is a quick summary of some of the things I learned last week:
  1. Students LOVED the new Moving Rainbow kits I built.  Although some designs worked better than others.
  2. The device is wonderful but still lacks some features that would make it easy for students to use in classrooms.
  3. Getting IoT remote devices  to work requires specialized skills (like C parsers) that many of us don't have.
  4. When students get their own ideas for projects they get laser focus
  5. Hackdays are a lot of fun!  They are great ways to meet people and learn from others.

I had two roles at the hackfest.  I helped setup and run the "Kids Room" for the hackfest and I did a (very) little work in the Lumière lighting team.

For the Lumière team I mostly helped a few people to learn how to solder wires the LED strips and use heat shrink to secure the wires.  The other two guys on my team (Daniel Feldman and Alan) had much better programming skills and experience with other platforms like the Raspberry Pi.

I did spend many hours working on building an XForms, REST, XQuery application for the  And although I did get it working (video), it still needs a lot of polish to allow the commands to be flexible.  I also did get a few new patterns working:
  1. Larson Scanner (Cylon)
  2. Random colors
  3. Candle flicker (simulate the light flickering pattern of real candles)
  4. Up-down patterns
  5. Swipe (redraw colors one pixel at a time)
Many of these still need to be parameterized with arguments such as color and speed.  However doing a general interface still needs work.

To get the Internet-of-Things (IoT) moving rainbow kits to work we need to send a specific "change color pattern" command to each device.  Since the interface only accepts a simple string, we need to parse the strings into a pattern of colors and motion.  However none of use knew how to use the strtok_r() function so we struggled a bit.  Daniel did a great job under pressure getting one command parser working on the, however we will need to refine it a bit more over time.

The ideal long-term solution is to develop a small "Addressable LED Strip Markup Language" as a domain-specific command language and write a parser for it in C that would run on the  This is a non-trivial problem for people that don't write C every day.  However I hope to spend some time thinking about the pattern name, color name, delay period syntax and perhaps coming up with a small BNF grammar.

Moving Rainbow Findings

Now I want to review some of the findings around a low-cost Arduino kits for students.

One of the dongle-style Moving Rainbow designs connected to an FTDI programmer

My primary interest is to understand what can we do to get students involved in STEM and to keep them on the strong math and science tracks in high-school and college.  Each time I engage with students I look for things that get them excited and want them to return for more.

My vision is to help design low costs kits that students could take home and show their friends.  These kits should be inexpensive enough that schools, libraries, and park buildings could have them for checkout, just like any library book.  Imagine a bookshelf at the library that contained 100 different electronic kits, each with specific learning goals in mind.

My experience has shown me that with some mentoring and some good electronics kits that many students can use internet resources to do a lot of work on their own.  However some students need a bit more encouragement then others.

This was one of the first times I had my newest collection of my "Moving Rainbow" kits on display.  When the students came into the room I encouraged them to pick up each kit and play with them.  Each of them has slightly different designs, packaging and switches.  When they flick the power switch on the 12-segment RGB LED lights came on and some of the kits had nobs and sensors that change the LED patterns displayed.  I tried to pay special attention to each of the students and they came into the room.  I noted what kits they picked up and what features they were interested in.

One of the things I learned is that there was little interest in the small-versions of the kits.  These were the ones that did not have room for the 12 pixels within the box.  These had a "dongle" design where the LED strip was sticking outside the boxes.  These designs pretty much failed, and looking back I can see why.  My reason to try them was that the smaller boxes were less expensive.  The larger boxes cost $5 or $6.  However, one of the students wanted to purchase the "dongle" designs.

The other thing to remember is that the logistics of getting the Arduino drivers working on both Windows and Apple systems is very time consuming.  Much of the first hour was getting the Arduino drivers working and the FTDI drivers (required for the mini-pros)  installed.

Several of the students did a "color wheel" lab where they had to mix the red, green and blue values together to make purple, yellow and orange colors appear on the LED strip.  The look on their faces when the strip turned either the right or wrong colors was priceless.  These were fantastic teaching moments!  On my TODO list is a "cheat sheet" for the color functions with pictures of color wheels.  This guide would start with functions to set a pixel to a specific RGB value and draw colors within for loops.

The moving color labs was a bit harder.  I need to continue to find good simple examples of lights moving up and down and get them pre-installed in the Arduino Examples area.  This is a great way to teach for loops and if/then/else logic.  As my sister and brother have told me, teacher prep makes a huge difference in students understand and lowering frustration levels.

One incident was that the students really loved the idea of creating a small wearable designs.  I had my "Altoids" example necklace as a demo to show them.  A few of them wanted to make Halloween costumes out of them.  And they were VERY motivated once they realized they could create their own costumes out of them.  At our final presentation to the entire group, two of them came to the front of the group to show their creations.  One of the students specifically thanked me in front of the entire group.  I wish all the students were this polite!

One idea is to have a "Arduino wearables" hackday around the same time next year.  This would require a lot of planning and some volunteer work by people with sewing machines.

What this taught me was that once students get their own idea of a creation it is like a fire-bolt of energy gets lit in them.  Their distractions disappear and they become laser focused on their task.  They seek whatever resources they can get to reach their goals.  Helping each student find their project is what these hackfests is all about!

I also met a few other people that might help us lower the costs of the packaging and find lower costs of the Moving Rainbow kits.  I still have more work to do to learn about placing larger quality orders for components and packaging on volume discount sites such as

I want to reach out and thank everyone that made the meetup possible.  The sponsors and the people at Minnetronix should get a special thanks!

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