I updated the github code to do the following:
- Display a 32x32 bitmap of the ISS at the current calculated location
- Display a trail of dots for the previous ISS locations.
The displayio.Group() structure can work like a stack. The history stack has a depth of 30. I pop off the first element when the length is 30 and then add a new one.
The ISS bitmap is offset 16x16 so the image is centered on the calculated X-Y instead of the top left corner.
My math seems to be a bit off with respect to the calculated X-Y. The history tail and the orbit from https://wheretheiss.at/ do not align. I have included a screen shot of each. I may increase the history to 90 so that a complete orbit can be visualized. Maybe the X-Y can be fudged.... or the path is wrong.