CATERPILLAR - Advanced roof and dome controller for observatories
Caterpillar is an observatory controller designed to automate and safeguard roof and dome operations in professional and custom-built observatories.
Originally developed for large installations, Caterpillar has evolved into a flexible control system capable of adapting to a wide range of mechanical designs.
It is based on Lunaticoastro’s Beaver control platform, the same hardware design used by the well-known dome manufacturer NexDome, with thousands of units in operation worldwide. This provides a well-proven technical foundation for reliable observatory control.
The controller can drive almost any existing motor and control a two element shutter. Weather and sky condition monitoring are provided by external systems, such as CloudWatcher or compatible rain sensors, which can be integrated when autonomous operation is required.
Depending on the installation, Caterpillar can operate as a stand-alone controller, or as part of a larger observatory control system together with Dragonfly or Starling.
Current product status
Caterpillar is currently available for selected projects and custom installations.
The controller is fully functional and already in use in several observatories worldwide. Hardware, firmware and software drivers are stable and documented, but not all possible combinations are fully covered in the hardware setup side yet.
As it is evolving from an OEM only version, final product packaging and enclosure are still being completed. For this reason, Caterpillar is not yet offered as a standard off-the-shelf product and is supplied directly to users who require a flexible, project-oriented solution.
Final system refinement and product completion are planned throughout 2026, with particular focus on the second half of the year.
During this phase, Caterpillar is offered under preferential project pricing, reflecting both its current status and the need for closer collaboration with users during integration, testing and real-world operation.
What Caterpillar does
✔️ Controls dome rotation and shutter or roof motion
✔️ Handles motors, encoders and limit switches directly
✔️ Re-syncs itself on crossing the home sensor (dome rotation)
✔️ Multiple safety measures to avoid equipment damage in case of limit switch or other mechanical failures
What Caterpillar does not do
✖️ Does not monitor sky or weather conditions by itself
✖️ Does not replace observatory management software
✖️ Does not enforce a fixed mechanical design
Caterpillar variants
The Caterpillar family includes different variants, each designed to address specific observatory motion and control requirements.
All variants support direct connection to external safety and weather sensors, such as CloudWatcher or Hydreon RG-11, enabling automated roof operation based on external inputs.
And all variants can self-calibrate (rotation, shutter, roof) for optimal accuracy.
Caterpillar
Caterpillar (full controller) is the full dome controller model with separate boards for rotation and shutter, auto connected via WiFi.
It supports a wide range of motor types (3-phase, DC, stepper, always with external drivers), encoders and limit and home switches, and connects to standard control platforms via ASCOM and INDILib.
Caterpillar SSR
Caterpillar SSR is a dedicated controller designed to automate stepper-motor based roll-off roof observatories.
It can operate as a stand-alone controller, communicating via USB or WiFi using standard ASCOM and INDI drivers, or be integrated into a larger observatory control system together with Dragonfly or Starling.
CaterpillarR
CaterpillarR is a relay-based model intended to retrofit existing observatories originally operated with manual buttons. It automates opening, closing and rotation through relays, while keeping precise encoder-based positioning.
How Caterpillar fits into your observatory
Motion and safety control
Caterpillar controllers are responsible for roof and dome motion, managing motors and monitoring encoders, limit switches and home sensor (where applicable).
External sensors
Weather and sky condition monitoring are provided by external systems. Typical integrations include CloudWatcher or compatible rain sensors, whose inputs can be used by Caterpillar to enable safe automated operation.
Observatory control and software
Caterpillar can be controlled directly using standard ASCOM or INDI drivers, or integrated into a higher-level observatory control setup together with Dragonfly or Starling, which coordinate additional observatory functions.
Technical overview
Connectivity
- USB connection
- WiFi connectivity
Motion control
- Roof and dome motion control depending on the Caterpillar variant
- Support for stepper motors only (Caterpillar SSR)
- Support for stepper, DC and three-phase motors (Caterpillar full controller, using external drivers)
- Low power relay-based motion control for retrofit installations (CaterpillarR)
Positioning and safety
- Encoder support for position feedback
- Limit switches and safety inputs
- Home position detection and resynchronization
External inputs
- Inputs for external safety and weather sensors
- Push buttons for CW / CCW rotation, open and close, and to trigger calibration
- Typical integrations include CloudWatcher and compatible rain sensors (e.g. Hydreon RG-11)
Software and control
- ASCOM drivers available
- Windows software to tune external motors (useful for the full controller only)
- INDI drivers available
- Can operate as a stand-alone controller or as part of a larger observatory control system
Documentation and resources
(coming soon)
Configuration interface
