Polish and Present – Nam Tran Ngoc

This past week I focused on making the globe much more presentable and reliable, both hardware and software wise.

The globe casing was causing me trouble since it was too small, so I scaled it up and doubled the size. This results in a massive globe at 13” diameter. And rather than winding the LED strip inside the globe I opted to glue it to the outside ridges of the globe. This has the effect of making the LEDs more uniform, at the cost of resolution, since there are only 10 ridges, at 30 LEDs each.

I also changed the original 150 count strip to a 300 LEDs count strip. This consumes more power but the latitudes would be more exact.

I decided not to go with a diffusing layer due to time constraint and difficulty finding a good solution to wrap around such a big globe.

Since the strip configuration changed I had to change the software to match. Instead of using Mercator globe projection to map the globe to a 2D surface, and then wrap it around a single strip; I kept the longitude and latitude data and re-scaled it to fit the globe resolution (10 latitude lines by 30 longitude pixels).

The result is a much cleaner look and a simple coordinate calculation algorithm.

I also implemented fading out animation. This makes the lightning strikes seems less like an epileptic-causing rave and more of a real life lightning feel to it.

One last feature I put in was adding two pre-set locations: Massachusetts and Hanoi, Vietnam. This has the effect of centering the globe and at the same time giving people a scale to work with.

Overall I’m happy with what I have so far and I’m excited to present it in class.

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