Final Project

I was thinking about possibly making an orrery, which is a small scale model of the solar system that can rotate. Most orreries out there are very expensive, so I thought it would be cool to make one myself.

Then I remembered The Pulse of Exploration by Dan Goods and thinking it was really cool. Then I thought about merging the two, and thought it would make a good project.

Instead of a traditional upright orrery, I was thinking about making it more clock-like, where the system is more compressed into (somewhat) the same plane. In between the planets, I would add rings of LEDs that would light up when a spacecraft in the vicinity of the planet is receiving or sending data. In the outer ring, antennas from each of the 3 DSN stations would light up as well when sending or receiving data. This would be pulling data from DSN Now for realtime updates.

As a fun addition, pushing the sun sends out a "pulse" that lights up active missions.

Progress

Designing and manufacturing cool PCB (and playing with LEDs) test

Stepper Motor

Board to Board Communication

Decided to drop planetary gear aspect.

Decided to split up one big board into smaller ones to maximize modularity.

DSN API working, able to get dictionary of current spacecraft working.

Decided to drop spinning orrery portion.

Uplink and Downlink LEDs working.

DSN API polling working, however was testing late at night and no spacecraft was showing up :(.

State machine between button and idle working, could not test polling atm.

Decided to just do inner solar system, with Jupiter and beyond Neptune. As of 2024, there are no spacecraft being launched to planets outside of Jupiter as of this time (sorry Dragonfly and UOP). The board is set up for all planets and outer solar system.

DSN API

For connecting to the DSN API, I knew of a friend who had done something similar. Adapting to Micropython (which doesn't have a good xml parser), I was able to get the uplinking and downlinking spacecraft mapped to the antenna.

Sun Button

Using the capacitance sensor, I would have a button also added a 3D printed

TFT Screen

Using a package for TFT for Micropython, I ran the graphics test to check if it works.

Code Integration

I decided to run a state machine, where there are 3 states:

  • IDLE: Just runs the sun button, runs an idle animation. Checks for button press, has a timer for polling.
  • POLLING: Polls DSN. Ideally polls every 5 minutes. Gets a list of all active spacecraft and whether there's up or down signals from the dishes. For all newly active spacecraft, it runs the uplink and downlink routine. Goes back to IDLE once done.
  • ACTIVE: When the button is pressed. Shows all currently active spacecraft with corresponding circles lit. goes back to IDLE once done.

Structure

Board

Antenna

Antenna

LEDs

Ground Station LEDs: can show uplinking and downlinking spacecraft.

Planet LEDs: Need to fabricate and place.

Materials Needed

  • Acrylic (acquired)
  • LED strips or lots of rgb addressable LEDS (acquired)
  • PCB boards (main board and stepper motor board acquired)
  • TFT screen (acquired)
  • Stepper motor (acquired)

Completed tasks

  • Calculate gear ratios
  • Get API working
  • Main board milled and full system coded up. Will remake board, but current board is as a backup.
  • Stepper Motor board completed and controllable
  • 3D print Sun
  • Get Sun button working
  • Get TFT screen working
  • 3D print antenna

Tasks to be completed

  • 3D model system
  • Lay out Planet LEDs
  • Get a one planet system working

Schedule

  • Week of 11/11: Calculate gear ratios and 3D model gear system. Start design and making LED circuit board.
  • Week of 11/18: Get one planet system working. Get API working. Get TFT screen working.
  • Week of 11/25: Keep adding planets, add sun?
  • Week of 12/2: Free space
  • 12/18: Presentation :3
Unfortunately a week late, but built in extra time to compensate.

Questions

  • How do intermediate gears affect gear ratio?
  • How do planetary gears work?
    • Cool simulation: https://www.thecatalystis.com/gears/
    • Tried to find ratios of the planets with respect to Mercury, but found it hard to create. Most likely will go with a regular orrery design.
  • How big should I make this thing?
    • Gears: Max 12 inch in diameter
    • PCB: Breaking up big board into main board, LED boards, and stepper motor boards.
  • How to break up large PCB design into smaller ones for the mill?
    • Answered above
  • Can Pi Pico connect to wifi for API requests, or would I need an ESP32?
    • Pi Pico W