Around the World in 48 Hours

Over the past few days, I've been working on maps and continents. I started with mapping out the locations of all my little pixels. I started with country capitals and then moved to US state capitals, Canadian provinces, and a few regions of Mexico and China. After placing my dots, I added lines to represent my wiring path. I put it all into a spreadsheet starting with the first pixel in the chain. I ended up with 284 pixel locations.

The next problem was getting the country cutouts to wrap around the frame. I bought foamed PVC sheeting from Monterey Signs. It's very flexible and can be warped with heat. Even then, the sheet did not curve to the sphere well. I then searched around and found an application from NASA that allowed me to make a Sinusoidal Projection with 15 degree gores.

Now it has to be cut out.

One Step at a Time

Today was all about getting the stepper motor turning. I did some tests yesterday but to no avail. The stepper motor didn't turn and when it did, it would rotate back and forth randomly. Today, after assigning correct values in the Arduino code, I got the motor to turn smoothly. It seemed to only like rotating at 10 rpm. Luckily, it was exactly the speed I needed it at.

After running the motor continuously for 15 minutes, I used my thermal sensor to measure the heat of the motor drive. It seemed to max out at about 80 degrees fahrenheit. I might need to install a small fan in the control box. After that, it was time for mounting.

Electrical Testing

Since the continent cutouts didn't work yesterday, I decided to start testing code and electronics. I started with the Adafruit ESP8266 Feather and the MicroSD card. I figured out how simple .csv files are so the ESP8266 could easily parse through the data. I then created a Google, Adafruit, and IFTTT account for interacting with the ESP8266.

I started to hook up the circuit to the 5v 30A power supply but realized that I ran out of crimp connectors. A quick run to orchard solved that.

Finally, the Adafruit package that I had been waiting for got delivered. It contained the Logic Level Converter that I needed in my circuit but I was really excited for the miniature fan I bought for soldering.

 It worked wonders.

A Day of Solder, Paper, and Vinyl

I finally spent the time to set up my soldering station. After mounting the electronics and designing the wiring, it was time to solder the circuit together. I had a fun time routing the wires in and around the boards. I also kept the circuit color coded like it was in the diagram I drew. By the time I finished, the inside of my electronics box looked like a land of rainbows.

My dad's work has a printer meant to print large blueprints and diagrams so he printed out the outlines of all the continents. We then started cutting out the paper borders to transfer them to vinyl sheeting but when we held up South America to the globe, we noticed the printout was a little to big. Oh well, we will have to try again another day.

Electrical Schematic

Today, I drew up a wiring diagram for my project. I drew this in Fritzing, an open source CAD software for the design of electronics. This was especially easy due to the ready made Fritzing library by Adafruit Industries. In fact, the design was so easy that most of my time was actually spent downloading the software.

This diagram is sort of a rough sketch for me to reference when I solder together the entire circuit. I did not include the 5v 30A power supply that would power the globe nor did I include all 500 NeoPixels. Just imagine the extra 497 pixels attached to the 3 pixels to the left.