sky-ceiling-projector 1.0.0

live-ceiling – Bring the Real-Time Sky Indoors

update: You can now install this using pip install sky-ceiling-projector!

Live-ceiling turns a Raspberry Pi Zero 2 W and any HDMI projector into a miniature planetarium that shows a weather-accurate, time-accurate sky for any city in the world—complete with stars, Moon phases, planets, shooting stars, clouds, rain, snow, lightning, and smooth colour transitions when you “fly” to another location. All data comes from free, no-key public APIs, so the setup can run indefinitely with nothing more than Wi-Fi.

✨ Key Features

• Real-time sky gradient that matches local dawn, day, sunset, dusk and night.

• Accurate weather effects powered by Open-Meteo’s Geocoding and Forecast APIs—no API key required. open-meteo.comopen-meteo.comopen-meteo.com

• Detailed celestial objects: variable stars, red/blue giants, Milky Way band, realistic Moon with pre-generated craters, Sun with sunspots, planets, satellites and meteor showers.

• Weather-sensitive particles for rain, drizzle, snow and fog, plus branching lightning during thunderstorms.

• Demo-mode “world tour” that cycles through famous cities on a timer (or on key-press) with a 5-second cross-fade.

• Optimised for Raspberry Pi Zero 2 W (quad-core 1 GHz, 512 MB RAM) so it runs smoothly at 1080p/30 FPS. datasheets.raspberrypi.comwired.com

• Pygame full-screen output with double-buffering and hardware surfaces for tear-free projection. stackoverflow.com

• Zero-cost libraries only: pygame, numpy, requests, geopy, timezonefinder, and pytz.

---

🛠️ Bill of Materials

Item	Notes
Raspberry Pi Zero 2 W	Any Pi works, but Zero 2 W is the smallest that can sustain 30 FPS. datasheets.raspberrypi.com
micro-SD card (16 GB +)	Flash the latest Raspberry Pi OS Lite.
Official Pi Zero camera/power adapter kit or 5 V/2 A USB power	The projector’s USB-A port usually provides enough current.
HDMI cable (micro-HDMI → HDMI)	Connects Pi to projector. Basic passive cables work. fromdev.com
Any HDMI projector (720p–1080p)	Short-throw or ceiling-mounted mini projectors work best.
Wi-Fi connection	Required only for live weather; sky still renders offline.

Tip: If your projector only has VGA, use an inexpensive HDMI→VGA adapter and enable hdmi_safe=1 in /boot/config.txt. ask.tvsbook.com

---

📦 Software Requirements

Package	Install command	Purpose
Python 3.7 +	sudo apt install python3 python3-pip	Interpreter
pygame ≥ 2.1	sudo pip3 install pygame	Rendering layer on Pi. github.com
numpy, requests	pip3 install numpy requests	Math & HTTP
geopy	pip3 install geopy	Fallback geocoder. gis.stackexchange.com
timezonefinder, pytz	pip3 install timezonefinder pytz	Local-time conversion. pypi.org

---

🔧 Installation

bash
CopyEdit
# 1. Flash Raspberry Pi OS (Lite or Desktop) to SD and boot.
# 2. Enable SSH & Wi-Fi using raspi-config if needed.
sudo apt update && sudo apt upgrade -y

# 3. Install SDL dependencies for pygame
sudo apt install libsdl2-dev libsdl2-image-dev libsdl2-ttf-dev libfreetype6-dev libatlas-base-dev -y

# 4. Clone the repo
git clone https://github.com/your-user/live-ceiling.git
cd live-ceiling

# 5. Install Python deps
pip3 install -r requirements.txt

# 6. (Optional) Test pygame opens in full-screen
python3 - << 'PY'
import pygame, sys
pygame.init(); pygame.display.set_mode((0,0), pygame.FULLSCREEN); pygame.time.wait(2000); sys.exit()
PY

If the screen stays black after step 6, verify HDMI-0 is enabled and the projector is on the correct input. raspberrypi.stackexchange.com

---

🚀 Running the Projector

bash
CopyEdit
# Basic: simulate current sky over Paris
python3 live-ceiling.py --location "Paris, France"

# High-performance preset for 480 p pico-projectors
python3 live-ceiling.py --preset performance --location "Tokyo, Japan"

# Demo mode: world tour every 5 min
python3 live-ceiling.py --cycle-cities --cycle-interval 300

Keyboard Controls

Key	Action
ESC	Quit
I	Toggle info overlay
D	Debug mode (cycles weather)
R	Regenerate starfield
SPACE	Trigger lightning (only if weather = thunderstorm)
N	Next city (demo mode)

---

⚙️ Configuration & Customisation

Flag	Default	Description
--preset	balanced	performance (≤ 15 fps), balanced (default), quality (> 20 fps on Pi 4)
--location	required	City or “City, State/ISO-Country”. Uses Open-Meteo geocoder. open-meteo.com
--cycle-cities & --cycle-interval	–	Rotate through a curated list of major cities.
--no-info	off	Hide FPS, weather and location overlay.

To add your own city list, edit WORLD_CITIES in the script.

---

🏎️ Performance Tips

• Run headless Raspberry Pi OS Lite to free RAM.

• Use the performance preset for 720 p or lower projectors; it halves star and particle counts.

• Disable glow effects by setting "enable_glow": False inside QUALITY_SETTINGS.

• To force 30 FPS, add pygame.time.Clock().tick(30) inside the main loop (already set).

• For multiple projectors, add an HDMI splitter; the Pi outputs the same frame to all displays. reddit.com

---

🩻 How It Works (Quick Tech Peek)

Component	Library/API	Notes
Geocoding	Open-Meteo Geocoding (primary) → Geopy + Nominatim fallback	No key, fast, returns local timezone. open-meteo.comgis.stackexchange.com
Weather	Open-Meteo “current_weather” endpoint	Supplies weather_code, cloud_cover, temperature, wind. open-meteo.com
Local time	TimezoneFinder + pytz for offline TZ lookup	Works without internet after first run. pypi.org
Rendering	Pygame 2 HW surfaces, double buffer	Full-screen toggle example: see StackOverflow. stackoverflow.com
Hardware	Pi Zero 2 W (quad-core A53 @ 1 GHz, 512 MB RAM)	Small, silent, $15. datasheets.raspberrypi.comwired.com
Display	HDMI out to projector	Any modern HDMI projector or TV works. fromdev.com

APIs are free for non-commercial use; Open-Meteo imposes reasonable request rate limits (60 calls/min). open-meteo.com

---

🐛 Troubleshooting

Symptom	Fix
Black screen on boot	Ensure projector input is HDMI #; add hdmi_safe=1 in /boot/config.txt if using adapters. ask.tvsbook.com
“pygame.error: No available video device”	Run with a screen attached or set export SDL_VIDEODRIVER=fbcon.
Weather always “Loading…”	Check internet; Open-Meteo requires outbound HTTPS port 443.
Wrong local time	Disable Wi-Fi power save (iw dev wlan0 set power_save off) and verify TZ in raspi-config.
Frame-rate dips below 20 FPS	Switch to --preset performance, close other processes, lower resolution to 720 p in /boot/config.txt.

---

🤝 Acknowledgements

• Open-Meteo – free weather & geocoding APIs. open-meteo.comopen-meteo.comopen-meteo.com

• Pygame – SDL-based cross-platform game library. github.com

• Geopy / Nominatim (OSM) – geocoding fallback. gis.stackexchange.com

• TimezoneFinder & pytz – offline timezone look-ups. pypi.org

• Raspberry Pi Foundation for the Pi Zero 2 W hardware. datasheets.raspberrypi.com

---

📄 License

This project is licensed under the MIT License (see LICENSE).

Happy sky-gazing! 🌌