The Ham Radio Control Libraries, Hamlib for short, is a development effort to provide a consistent interface for programmers wanting to incorporate radio and rotator control in their programs.

Hamlib is not a complete user application, rather, it is a software layer intended to make controlling various radios and other amateur radio station (shack) hardware much easier.  Hamlib will allow authors of software such as logging programs, digital communications programs, or those wanting to develop the ultimate radio control software to concentrate on the user interface and the basic function of the program rather than radio control.  Hamlib consists of several parts, the programming library, utility programs, and library interfaces to other programming languages.

Most recent amateur radio transceivers allow external control of their functions through a serial interface.  Unfortunately, control commands are not always consistent across a manufacturer's product line and each manufacturer's product line differs greatly from its competitors.

Hamlib attempts to solve this problem by presenting a "virtual radio" to the programmer by providing an interface to actions such as setting a given Variable Frequency Oscillator's (VFO) frequency, setting the operating mode, querying the radio of its current status and settings, and giving the application a list of a given radio's capabilities. Unfortunately, what can be accomplished by Hamlib is limited by the radios themselves and some offer very limited capability.

Other devices, such as antenna rotators, can be placed into the Hamlib control scheme.  Other recent developments include network interface servers and a USB interface capability.  Language bindings are provided for C, C++, Perl, Python, Lua and TCL (more to come).

A view from the top of the tower
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Hamlib is a front end library providing a C language Application Programming Interface API to programmers wishing to integrate radio or rotator control in their applications.  Hamlib presents a virtual radio or virtual rotator that is a consistent interface to an application despite wide differences in radio and rotator interfaces and capabilities.

The front end library uses a number of back end libraries to translate from the front end to the various individual radio and rotator models.  A back end library handles conversion of the front end variables to the format needed by the radio or rotator device it controls.  The back end libraries are generally grouped by manufacturer and in some cases by a common control protocol.

     Since a picture is worth quite a few words, here is a visual representation of Hamlib's design.

     Hamlib Design
     Figure: Hamlib design---courtesy of Martin Ewing, AA6E.

Hamlib also provides an interface library for each of several common scripting languages such as Perl, Python, Lua and TCL.  These language bindings are generated through the use of SWIG a parser/generator for multiple language interfaces to a C library.  A native generated C++ language interface is also provided.

Besides the C and supplemental APIs, Hamlib also provides a pair of network daemons that provide a text command based API for controlling an attached radio or rotator through a TCP/IP network connection.  The daemons then handle the interface to the Hamlib C API.

More than one type of device, radio or rotator, may be controlled at a time, however, there is generally a limit of one device per serial port or other port.

Hamlib project information
==========================

The Hamlib Project was founded by Frank Singleton,VK3FCS/KM5WS in July 2000.  Shortly after Stephane Fillod, F8CFE, joined Frank on the Hamlib project and the API and implementation development led to a reasonable level of maturity in a few years.  A major milestone was reached when Hamlib 1.2.0 was released in March 2004.  The API and Application Binary Interface (ABI) interfaces have remained stable since that time up to the latest release of 3.2 in early 2018.

Development continues through the major version number 3.x and beyond. While some API tweaks are planned, ABI compatibility with the prior 1.2.x releases remains a priority.  Other goals include streamlining the build system (done), improving the SWIG generated language bindings (done), improving the overall documentation (this manual, in progress), and other updates as warranted.

The Project is hosted by SourceForge.net (https://sourceforge.net/) at the Hamlib project page (https://sourceforge.net/projects/hamlib/).  As GitHub (https://github.com/) has become a very popular project hosting site, Hamlib also has a dedicated GitHub project page (https://github.com/Hamlib/Hamlib).  GitHub also hosts the hamlib.org (http://www.hamlib.org) Web site and the Hamlib Wiki (https://github.com/Hamlib/Hamlib/wiki).

Development discussion and most user support take place on the hamlib-developer mailing list (https://sourceforge.net/p/hamlib/mailman/).  While there are SourceForge.net discussion forums (https://sourceforge.net/p/hamlib/discussion/), they are rarely used and not as closely read by the developers as the mailing list.

For source code management, the project uses Git (http://git-scm.com/), a fast, distributed content tracker. Among its features is that every developer has the complete Hamlib development history available locally.  For more information on using Git, see Working with Git.

     While a canonical Git repository is hosted as SourceForge, its availability is not essential to continued development, although development work flows would change temporarily.  Several developers find the GitHub Web interface easier to use and lately development has centered around GitHub rather than SourceForge.

Applications using Hamlib
=========================

A number of application developers have taken advantage of Hamlib's capabilities to implement radio and/or rotator control.  While not exhaustive, a list is maintained at the Hamlib Wiki, Applications/Screenshots (https://github.com/Hamlib/Hamlib/wiki/Applications-and-Screen-Shots).  Developers are encouraged to request their applications be added to the gallery by way of the hamlib-developer mailing list.

Using Hamlib with your program
==============================

As with other Free Software projects, Hamlib relies heavily on copyleft licensing to encourage development contributions and provide an open atmosphere for development.  Hamlib's source code is released under two licenses, the Lesser General Public License (LGPL) for the library portion, and the General Public License (GPL) for the utility programs.

The LGPL allows the library to be used (linked) by programs regardless of their individual license.  However, any contributions to the library source remain under copyleft which means that the library source code may not be used in violation of the terms of the LGPL.

The utility program source files are released under the GPL.  Any direct use of these sources must be in a form that complies with the terms of the GPL.  Concepts learned by studying these sources for the purpose of understanding the Hamlib API is not covered nor prohibited by the GPL, however, directly copying GPL sources into any work that is incompatible with the terms of the GPL is prohibited.

See Copying and Redistribution.

Radios with a clone capability
==============================

Hamlib's focus is on controlling rigs that employ a port and command protocol for setting frequency, mode, VFO, PTT, etc.  Most VHF/UHF transceivers do not employ such control capability but do provide for cloning the memory contents from radio to another of the same model. A related project, CHIRP (http://chirp.danplanet.com/), aims to support radios with such a clone capability.  Please contact the CHIRP project for support of such radios.

Pronouncing Hamlib
==================

English speakers seem to have two alternate pronunciations for our project:

  * Hamlib (Ham - lib, long "i", as in library.) IPA style: /'ham læb/

  * Hamlib (Ham - lib, short "i", as in liberty.) IPA style: /'ham lɪb/

Then again, we have people who say Linux "L-eye-nux" and those who say "L-in-nux"...

If you're French, the above does not apply! :-)