Tutorial Eight: Rotator

This tutorial demonstrates how to create a simple rotator device driver. A rotator is a device that can rotate a camera or other instrument to a specific angle, which is useful for framing targets or for field de-rotation during long exposures.

What You’ll Learn

  • How to create a rotator driver by inheriting from INDI::RotatorInterface
  • How to implement angle control and movement simulation
  • How to handle rotator-specific properties and commands
  • How to integrate the rotator interface with the DefaultDevice class

Source Code

The source code for this tutorial can be found in the INDI library repository under the examples/tutorial_eight directory.

INDI Rotator Interface

The INDI Rotator Interface provides a standard way to control rotator devices. The key components are:

  1. Angle Control: Setting and reporting the rotator’s angle
  2. Movement Control: Starting, stopping, and monitoring rotator movement
  3. Reverse Direction: Ability to reverse the direction of rotation

Code Explanation

This tutorial demonstrates:

  1. Rotator Implementation:

    • Creating a class that inherits from INDI::DefaultDevice and implements INDI::RotatorInterface
    • Initializing rotator properties
    • Implementing the required interface methods

  2. Angle Control:

    • Setting the target angle
    • Simulating movement to the target angle
    • Reporting the current angle

  3. Additional Features:

    • Implementing reverse direction functionality
    • Handling abort commands
    • Simulating realistic rotator behavior

Running the Tutorial

To run this tutorial:

  1. Build the tutorial using CMake:

    cd /path/to/indi/build
make

  2. Run the INDI server with the tutorial driver:

    indiserver -v ./tutorial_eight

  3. Connect to the server using an INDI client (like KStars/EKOS or INDI Control Panel).

  4. You should see the rotator device in the client, and you can connect to it and control its angle.

Conclusion

This tutorial completes our series on INDI driver development. We’ve covered a wide range of topics, from basic device drivers to specialized interfaces and inter-driver communication. With these examples, you should have a solid foundation for developing your own INDI drivers for various astronomical devices.

For more information and advanced topics, please refer to the INDI Library Documentation and the INDI GitHub Repository.