INDI Technical Documentation

Welcome to the home of INDI technical documentation. Here you will find information on how to build INDI drivers and clients, as well as information on the INDI protocol itself.

First, some helpful links:

• INDI Links
  • INDI Main Repo
  • INDI 3rd Party Repo
  • libindi API Docs
  • INDI Stable Builds
  • INDI Nightly Builds
• Build Tools
  • CMake
• Helpful Libraries
  • libnova
  • libgsl
  • libcfitsio
• Bundled Header-only Libraries The following C++ header-only libraries are included with libindi and may be used by any driver to handle common tasks around JSON and RESTful web services.
  • json: Write & parse JSON in INDI drivers (e.g. Primalucelab Devices)
  • httplib: Create http(s) servers and clients. Make GET/POST/PUT calls for RESTful services (e.g. Planewave Mount).
  • inifile-cpp: a simple and easy to use single header-only ini file en- and decoder for C++ (e.g. Planewave Mount).

Introduction

The Instrument-Neutral-Distributed-Interface control protocol (INDI) is a key technology for device automation and control. INDI introduces a control protocol standard for rapid development of robust, adaptive, and scalable device drivers under several platforms.

INDI has many advantages over similar technologies, including loose coupling between hardware devices and software drivers. Clients that use the device drivers are completely unaware of the device capabilities. In run time, clients discover the device capabilities through introspection. This enables clients to build a completely dynamical GUI based on services provided by the device. Hence, when new or updated device drivers are developed, clients can take full advantage of them without any changes on the client side; thanks to the self-describing nature of INDI.

Since developers don't have to worry about updating GUI clients to reflect changes in their drivers, they can concentrate their time and effort on the development and testing of drivers. This leads to a significant cut in development time and cost, and paves the way for painless maintenance and efficient deployment. Employing XML as the language of the protocol adds other advantages as the protocol can be parsed and processed using any XML library.

Furthermore, remote control of devices is seamless with INDI's server/client architecture. Distributed devices can be controlled from one centralized environment.

The INDI wire protocol only describes the rules, structures, and mechanisms underlying the protocol's architecture. What will be discussed throughout this manual is a specific POSIX implementation of the INDI protocol. We shall refer to this implementation hereforth as the INDI library.

The INDI library is released under the GNU Library General Public License (LGPL) and is currently maintained in the libindi GitHub repo.

Intended Audience

The INDI library is geared toward experienced programmers planning to develop backend hardware drivers to run under the INDI architecture. The task of developing hardware drivers requires programmers with sufficient experience in at least one high level programming language such as C++.

Naturally, you need to understand the ins and outs of your hardware thoroughly. This includes communication, control of electronics/motors, physical limitations, and safety considerations.

While the INDI wire protocol is platform-independent, the official INDI Library is designed to operate specifically on POSIX platforms. Developers can port the library and device drivers to different platforms as desired.

Supported operating systems include:

• Linux: Full Support
• MacOS: Full Support, except for few Linux-only drivers.
• Windows: Partial driver support via Cygwin. Client support.
• BSD: Full Support, except for few Linux-only drivers.
• iOS: Client support only.
• Android: Client support only.

INDI Library provides Python client bindings to access INDI server and drivers.

Getting INDI

Linux/Mac

• INDI Downloads

Raspberry Pi

• Astroberry Repo
• AstroPI3 Script

Source

Instructions for building from source are available in the GitHub repos.

• INDI GitHub
• INDI 3rd Party GitHub

Contributing

As an open source project, you can contribute to making INDI better. See the repositories above to make code contributions. You can also help make the documentation better by forking the docs repo, making changes in your fork, and creating a merge request.

Any help you can provide makes INDI a better project!