Dome Controller

Arduino firmware for R2-D2's dome servo expander, running on an Arduino Pro Mini (16 MHz, ATmega328). Built with PlatformIO.

Written by Jessica Janiuk (thePunderWoman), iterated from John Thompson (FrettedLogic), based on Chris James' foundation.

What it does

This board sits on the R2 serial bus and listens for DM: prefixed commands. When it receives one, it drives the dome's panel servos through the requested sequence and forwards the appropriate commands back out over serial to:

• AstroPixelsPlus (holo projectors, via * commands)
• Astropixels / logic displays (via @ Marcduino commands)
• Body controller (via BD: prefixed commands)

Hardware

• MCU: Arduino Pro Mini 16 MHz (ATmega328)
• Servos: 12 × VarSpeedServo, driven directly from digital pins 2–13
• Serial: Hardware Serial at 9600 baud (shared RX/TX bus)

Panel assignments

Panel	Pin	Type
PP1	2	Pie panel
PP2	3	Pie panel
PP5	4	Pie panel
PP6	5	Pie panel
P1	7	Low panel
P2	8	Low panel
P3	9	Low panel
P4	10	Low panel
P7	11	Low panel
P10	12	Low panel
P11	6	Low panel
P13	13	Low panel

Pin 13 doubles as the status LED — it illuminates while a command sequence is running.

The Dome Topper panel (DT, originally pin 6) is defined but currently commented out.

Serial command protocol

Commands arrive on hardware Serial at 9600 baud, terminated with \n or \r. Only messages prefixed with DM: are acted on; everything else is ignored.

DM:COMMAND

Supported commands

Command	Description
DM:RESET	Close all panels, reset holos and logics
DM:PIES	Toggle pie panels open/closed (waves on open)
DM:LOW	Toggle low panels open/closed (waves on open)
DM:OPENALL	Toggle all panels open/closed
DM:LEIA	Leia hologram sequence (36 s, then auto-reset holos)
DM:HEART	Rainbow holos + "You're Wonderful" marquee (10 s, then auto-reset holos)
DM:HELLO	"Hello There" — P1 waves, marquee message
DM:SCREAM	Scream sequence — all panels open, holos flash, body scream audio
DM:FLUTTER	Flutter all panels
DM:MUSE	Toggle Muse mode (body controller)

Non-blocking holo timer

Some sequences run the holo projectors for a fixed duration before resetting. This is handled with a non-blocking millis()-based timer so the main loop stays responsive:

• scheduleHoloReset(seconds) — schedules resetHolos() to fire after N seconds
• clearHoloTimer() — cancels a pending scheduled reset
• checkHoloReset() — called every loop iteration; fires the reset when due

resetHolos() always calls clearHoloTimer() first, so a manual reset correctly cancels any pending auto-reset.

AstroPixelsPlus holo commands

Holo projector commands use the * prefix and are forwarded over the shared serial bus. HP IDs: 01 = front, 02 = rear, 03 = top, 00 = all.

Command	Effect
*ST00	Reset all holos
*ON0x / *OF0x	Turn a holo on or off
*RD0x	Random movement
*HN0x	Nod (up/down)
*HP[pos][id]	Move to preset position (0=down … 8=lower right)
*HPS1[id]	Leia LED sequence
*HPS3[id]	Dim pulse
*HPS6[id]	Rainbow
*HPS7[id]	Short circuit (alarm flash)

Project structure

src/
  Dome_Controller.ino   Main sketch
lib/
  Filthy/
    FlthyHPs_v1.8.ino   Reference — original Filthy HPs I2C command set
  README.md             Third-party library install instructions
include/                (empty, PlatformIO default)
platformio.ini          Build config — Arduino Pro Mini 16 MHz

Building

1. Install PlatformIO (CLI or VS Code extension)
2. Clone VarSpeedServo into lib/
3. pio run to build, pio run --target upload to flash