I started to create a kind of object database for the explorad. The first kind are the Messier Objects. Why those? When Charles Messier started to look out for deep sky objects, he didn't have the technology we have now, so the set of objects he listed is quite short (112 items). This amount is quite easy to handle, but it's enough to demonstrate that the object database will be quite complex and large for such a simple system like the Teensy 3.1.

I used the table from this site to generate a text file with raw messier object data, parsed that with a simple C++ program I quickly hacked together and saved the result on the SD card that sits behind the OLED display. Each Messier Object is 19 bytes long. That doesn't sound like a lot, but the overall amount of data for those 112 objects is 2128 bytes already. And that's just a tiny amount of what we can see up there!

Anyway, the explorad now knows about the Messier Object's

• number,
• "proxy" name (used for links to other catalogues like the NGC and WNC),
• parent constellation (don't know if I'm going to use that...),
• type (might be useful for filtering displayed objects),
• coordinates (right ascension and declination)
• and magnitude (also a candidate for filtering).

I'll now figure out and implement a system that allows me to populate a list of objects that will actually be shown in the explorad's display. This list will most probably be far too big for the amount of RAM I have left, so there must be some kind of tiling, dynamic loading and unloading of tiles, filtering, and so on.

Also, more object types should be included. Solar system bodies (planets and such) are definitely a candidate for this. Or the International Space Station. Unfortunately, the coordinates of the planets around us are far more dynamic than those of e.g. the Andromedy galaxy. That's going to be interesting.