I haven't had much time lately to work on my own projects, but couldn't resist this one with Halloween coming up. This project is based on one from Adafruit, called the Superhero Power Plant. The original project uses Adafruit's Neopixel Ring, one FLORA neopixel, and a Gemma board. It also comes with downloadable artwork for laser cutting and engraving. Perfect timing!

I made small adjustments, switching out the Gemma board for a Trinket, which is what I had available. Think of the Trinket and the Gemma as tiny Arduinos, sort of. They aren't equipped with as many pins, and actually work a bit differently. For example, with an Arduino Uno, I can connect via the serial USB, send data to the board and receive data back. The Trinket doesn't allow for serial connection over the USB, and requires something called a Bootloader. If you'd like to learn more, see this Overview of Trinket from Adafruit's Learning System.

While there is a slight learning curve involved with getting Trinket to talk with the Arduino IDE, it was worth the time. The big advantages to Trinket (and Gemma) are size and cost. As you will see in the photos below, the Trinket is very tiny, and as of this writing, costs a mere $8.

I won't go over the tutorial, as that is available from the link above. I will say that it took some trial and error to get the soldering just the way it needed to be, and in the end I used a larger battery pack than what was stated as I knew the Trinket had a voltage regulator and could handle the extra input. Overall, a fun project!

After two months sitting in PIRL Terrace, the laser cutter got its first run. We purchased a 5th generation Full Spectrum Hobby Laser due to the good reviews and decent price for an entry level laser cutter.  As this was my first experience with technology of this type, I really didn't know what to expect. The initial set up was fairly pain free, but there are a lot of pieces to the puzzle beyond the cutter. I was a bit nervous while making sure the air compressor, the water pump and 5-gallon bucket, and the exhaust fan/hose were all set up correctly. I used BoxMaker online to download a test design of an interlocking box. You can see the results below. I added the two holes on top for pencils.

The students continued their work on individual projects this week. We were able to meet three days, so some work was done in Creator's Studio, while one day was spent in PIRL Terrace. The projects are really coming along now. Boe-Bot robots advance on their Arduino sketches. Boats are assembled using laser cut prototypes designed in Apple's Pages application, of all things. An Arduino driven RC Car is tested with new sketches. Light cube sides are sanded and boards are wired. An LED watch assembly receives the soldering of its components. Trebuchet pieces are drilled, cut and sanded.

Photo credits - Reynaldo Macias, 10-25-2013

This week the class only met once, but we took advantage of every minute we had. The trebuchet projects needed wood cut, so we met in PIRL Terrace to have access to the miter saw. 

After an introduction of some new materials (acrylic sheets and foam sheets) and how to cut them, we all brought our required tools and materials down to PIRL Terrace to continue our project work. In the gallery of photos below, students are seen working on their individual projects in this new outdoor space.

The light cube projects are trying out the new acrylic sheets for the cube structure. It appears to work better than the material we had at the beginning, as cuts are easier and cleaner. The boat projects are using the foam sheets with a glue gun to prototype their models. We also 3D printed some propellers from Thingiverse to try out with the RC air boats.

The trebuchet creators were given a thorough walk through of the miter saw, and then made their measured cuts under my supervision. They also sanded down their pieces of PVC.

One student completed his Boe-Bot project, and in the video at the bottom of this post, you will see that he programmed it to navigate based upon feedback from its IR sensors.

All projects are in different phases of development, as expected. While some have reached a level of independence and flow, I can spend more time supporting those that need the additional help. 

So aside from the session on hacking an RC toy, which you can read about in the previous blog post, this week was mostly about individual project work. I call these types of sessions "Build Days". We might have a small introductory lesson, or general housekeeping, but most of the time is dedicated for them to advance on their projects. Here's where some of them stand:

1. The Boe-Bot projects are advancing, one has already programmed the robot to navigate on the ground.
   
2. An RC car project is waiting for a chassis. However, prior to its arrival the student is working on Arduino and has already programmed two servo motors to move simultaneously. He borrowed some code from the Boe-Bot project, and adjusted it to work with an Arduino Motor Shield.
   
3. The light cube projects are going well. One will use an Arduino so that code can drive the color of the light that gets produced from the RGB LEDs. 
   
4. The trebuchet projects are moving quickly now that they have the materials to cut and test out. Today we even discussed the possibility of integrating some technology, like an arduino or RC driven trigger.
   
5. The RC boat groups will need to test some prototype boats to see what materials work best. One group wants to use a plastic bin, another student is building his own prototype out of some acrylic material we have here in class.
   
6. Soldering has become a solid tool for a couple of projects here.

Overall a very productive week. Here are some photos of the students in action.

This week I realized we needed to come up with a plan B for some of the remote control (RC) related projects. I was struggling with the fact that while it's fairly easy to get up and running with sensors and actuators on Arduino, like light and motion sensing, buttons and switches, it's another level altogether when it comes to wireless technology. 

On the one hand, we could delve into XBEE, or possibly in the near future use other tools like BLEduino or Flutter. But I'm not sure if I can spend that much time on the wireless control and programming when there are other aspects to their projects that students want/need to explore. There is a lot of prototyping to do, and integration of Arduino for some, and I want to make sure they get that exposure and time. For this stage, the prototyping and simple programming is more relevant.

Therefore, on the other hand, we could simply hack an RC and use its parts. I sent out an all-points bulletin to my faculty today to see if there are any folks who have old toys, like remote control cars and boats, that they wouldn't mind donating to the class. I will ask the parent body later today.

In the meantime, I purchased a very cheap ($14) RC Car from Radio Shack, and will hunt down all Goodwills and Salvation Armies in my neighborhood in the coming days. I tested out this cheap toy to make sure all was in working order, then took it apart with the students.

Guiding questions prior to opening up the toy: 

• "What's going on inside the transmitter, what do you think it's doing?"
  
• "What's going on inside the car? What makes it react the way that it does?
• "Which components, that we've already learned about in class, do you think are inside?" 
• "Since we know there must be motors, what kind are they, and how many are there?"

It was a really good conversation as students hypothesized what's inside and how things worked. We all guessed, incorrectly, that there would be a servo motor controlling the steering in the front. As it turns out, there's a clever way of using a standard cheap hobby motor to steer instead. The hobby motor at the front has a plastic piece that acts like a steering column. Turn the motor one way, car goes left, turn the other way, it goes right. You will see it in the photos below. Servo motors are relatively expensive, so hobby motors make more sense.

Finally, we discussed how we can take a car that does forward/reverse and left/right, and repurpose the technology in our projects. For example, an RC boat may use the steering as a rudder and the other motor can propel. A helicopter, if engineered lightly enough, might use the motors to get up in the air. There are many possibilities. 

For more information on RC Cars, see this article from How Stuff Works.

This week we revisited the Makey Makey so that students could experiment with some sites that were blocked during the last class. They started off with the How-To page at Makey Makey, then tried out other sites they knew would work with keystrokes. Some students also used Garageband. In Garageband, you can select a piano, then go to Window...Musical Typing, in order to make the keyboard, and therefore Makey Makey, respond as piano keys.

Students also had the opportunity to advance on their individual projects this week. I think it makes sense for the class to split our three days per rotation into some instruction and some project work. The instructional side will cover concepts that benefit everyone, where the project work is unique to each individual, with me serving as mentor/consultant. 

I have also opened up office hours, or "consultant time" one day per week so that students needing extra support can come in and work on their projects.