Born from large professional installations, now available for custom and advanced observatories worldwide
The Caterpillar automates and safeguards dome rotation and roof operations in professional and custom-built observatories. Based on the Beaver platform—the same hardware design NexDome ships worldwide, with hundreds of installations behind it.
Caterpillar is a precision motion controller, not an all-in-one observatory brain. Understanding its role helps you plan the right system architecture.
Rotation and shutter, limit switches, home sensor, encoder and driver, plus WiFi and USB connectivity for any of the three supported motor types.
All variants support external safety and weather sensor inputs, and all can self-calibrate for optimal positioning accuracy.
Supplied without an enclosure. 3D enclosure designs and STL files are free to download.
A complete dome control system, with separate boards for rotation and shutter that connect to each other automatically over a dedicated second WiFi channel. Supports a wide range of motor types—3-phase, DC and stepper (always with external drivers)—plus encoders and limit/home switches.
Each Caterpillar LOCo board—Lunaticoastro Observatory Control—drives a single observatory component, either the dome rotation or the shutter, so a dome with a motorised shutter normally needs two boards. Available in four configurations: main board only (for an existing compatible external driver), with the Lunaticoastro Relay Expansion Board (digital outputs, typically for VFDs and three-phase motors), with the Cytron MD13S 13 A DC motor driver, or with the DM860I stepper driver (2.4–7.2 A, 20–80 VDC). An optional flap module adds a second moving element on the shutter board.
Relay-based model designed to retrofit existing observatories originally operated with manual buttons, allowing control via four switches. Automates opening, closing and rotation through relays, while maintaining precise encoder-based positioning.
USB and WiFi (both station and access point), over-the-air self-updating firmware, complete auto-calibration and advanced on-the-fly rotation resync. Runs on 12 V at about 50 mA with the motors stationary. Safety measures include low battery level, rain, weather, missing or failed limit or home switch and communication problems.
Answer two quick questions in our interactive tool and get the exact controller, hardware checklist and documentation links for your setup—dome or roll-off roof, existing motor or button-operated drive.
Open the Setup Finder ↗Caterpillar works as one layer of a well-designed observatory control system, responsible for motion, while other systems handle weather and coordination.
Caterpillar manages motors, reads encoders and limit switches, and executes safe open/close/rotation sequences. It is the layer closest to the mechanics.
Weather and sky safety are provided by external systems whose inputs Caterpillar accepts to enable automated, safe operation.
The Caterpillar ASCOM driver integrates with ASCOM Device Hub and any ASCOM-compatible automation software: USB or Wi-Fi connection, full configuration and real-time control.
| Connectivity | USB + WiFi |
| Motor types (FC) | 3-phase, DC, Stepper (with external drivers) |
| Motor types (SSR) | Stepper only—hence Small Stepper Roof |
| Motor types (Caterpillar-R) | Existing drive, switched through relays |
| Positioning | NPN quadrature encoder (required for dome rotation, optional for the shutter) |
| Limit switches | Required for the shutter and flap |
| Home sensor | Required—Hall-effect or mechanical; re-syncs dome rotation position |
| External inputs | Safety and weather sensors |
| Manual controls | Push buttons for CW/CCW, open/close, calibration |
| ASCOM drivers | Dome + switch |
| INDI | Available (compatible with the NexDome Beaver driver) |
| Self-calibration | Rotation, shutter and roof |
| Enclosure | Supplied without an enclosure; free STL files for 3D printing |
| Platform | Based on Beaver (used by NexDome) |
Windows software available for tuning external motors (full controller variant). Firmware updatable by the user.
Build your own integrations with Lunaticoastro devices. Every command travels over plain HTTP, USB or UDP—one protocol shared across the whole range, so what you learn on one device works on the next.
Explore SLP391 commands · 12 devices · try one from your browser
Every command the Caterpillar understands, over HTTP, USB or UDP—one protocol shared across the whole range. For scripting and custom integrations.
Every manual, driver and guide for the Caterpillar, on one page—together with the rest of the range.
Overview covering all Caterpillar variants: architecture, wiring and integration.
Read manual →Specific guide for the relay-based retrofit variant.
Read manual →Specific guide for the roll-off roof stepper motor variant.
In preparationLatest ASCOM driver for Caterpillar Dome Full Control and Caterpillar-R.
Download driver →Firmware binary for the relay-based retrofit variant.
Download firmware →Firmware binary for the roll-off roof stepper variant.
Download firmware →Two questions—dome or roll-off roof, motor drive or buttons—and you get the right controller, the hardware list and the matching manuals.
Downloadable STL files for enclosures, adapters and mounting brackets for the Caterpillar system.
