Astro-Pointer-Outer-Abob (Laser Pointer Pan-Tilt Servo on Stepper)

thingiverse

I teach classes where we build amateur satellite antennas and attempt to listen to satellites and the International Space Station. It's extremely challenging to point at nothing, so I created this device (at least during nighttime). This gadget also features a handy modification that allows it to pinpoint astronomical objects by adjusting the pyephem script slightly (I'll share another program for this as well). This device uses a laser pointer to highlight targets at night. It's essential to never use it unattended, or you might attract unwanted police attention by shining a light into an airplane on approach. Initially designed to run on a Raspberry Pi, the project can also be executed on laptops and other computers. The Python script loads a TLE (Two-Line Element) file located in TLE.txt within the same directory and sends altitude plus azimuth commands through the serial port to the Arduino microcontroller. The Arduino then decodes these commands and instructs the servo and stepper motors accordingly. To address the unstable motion of the laser, I implemented a suboptimal algorithm for the servo motor. However, the stepper motor's linear motion offers room for improvement. Check out this project on YouTube: https://youtu.be/uu8M_wjfsk4 For further information and code, please visit: http://wiki.nebarnix.com/wiki/Laser-Pointer-Tracker-Abob