Fldigi

Fldigi is based on the lightweight portable graphics library FLTK and the C/C++ language. Because of this, the software can run on many different operating systems such as:

• Microsoft Windows (2000 or newer)
• macOS
• Linux,{{cite web|url=https://packages.debian.org/jessie/fldigi|title=Package: fldigi (3.22.01-1)|accessdate=6 May 2017|publisher=Debian}}
• FreeBSD,{{cite web|url=http://portsmon.freebsd.org/portoverview.py?category=comms&portname=fldigi|title=FreeBSD port|website=freebsd.org}}
• OpenBSD,{{cite web|url=http://cvsweb.openbsd.org/cgi-bin/cvsweb/ports/comms/fldigi/|title=ports/comms/fldigi/|publisher=OpenBSD|accessdate=6 May 2017}}
• NetBSD,{{cite web|url=http://pkgsrc.se/ham/fldigi/|title=pkgsrc/ham/fldigi/|publisher=NetBSD}}
• Solaris.{{cite web|url=https://fedorahosted.org/fldigi/wiki/Documentation/FAQ|title=Infrastructure/Fedorahosted-retirement - Fedora Project Wiki|website=fedorahosted.org}}

Additionally, Fldigi is designed to compile and run on any POSIX compliant operating system that uses an X11 compatible window system / graphical user interface.

The Fldigi software is written in highly portable C/C++ and can be used on many CPU architectures, including:

• amd64
• i386
• armhf/armel
• ia64
• mips
• mipsel
• powerpc
• s390
• s390x
• sparc
• Raspberry Pi.{{cite web|url=https://packages.debian.org/search?keywords=fldigi|title=Debian -- Package Search Results -- fldigi|website=packages.debian.org}}

Multiple sound systems are supported by Fldigi, allowing the program to abstract the sound card hardware across differing hardware and operating systems.

• Open Sound System (OSS)
• PortAudio
• PulseAudio
• Read / write to WAV files (file I/O)

• NBEMS: The narrowband emergency messaging system{{cite web|url=http://www.arrl.org/nbems|title=NBEMS|website=www.arrl.org}}[https://www.liltechdude.com/portfolio/Data_Networks.pdf Long Haul VLF/LF/HF Data Networks] liltechdude.com
• Support for transmitting and receiving in all languages by using UTF-8 character encoding (some modes)
• Connection to external programs via TCP/IP port 7322{{cite web|url=http://www.w1hkj.com/FldigiHelp/config_io_page.html|title=FLDIGI Users Manual: Configure ARQ/KISS I/O|website=www.w1hkj.com}}
• Ability to be used as a KISS modem via TCP/IP port 7342
• Dual-tone multi-frequency (DTMF) encoding and decoding
• Automatic switching of mode and frequency by use of Reed Solomon Identifier signal identification
• Inbuilt macro language and processor for programmable automated control
• Sound card oscillator frequency/skew correction
• Measure sound card oscillator's skew to atomic clock: WWV or WWVH
• Measure RF receiver frequency skew to atomic clock: WWV or WWVH
• Transmit a WWV-like time signal as a calibration reference
• Control of external transmit / receive radio hardware by using GPIO pins. (For embedded hardware)
• Simultaneous decoding of multiple morse code (CW) signals.
• Decoding of morse code (CW) by self-organizing map artificial neural network (trained artificial intelligence)

The "Fldigi Suite" consists of the Fldigi modem and all extension programs released by the same development group. Most of these extensions add more capabilities to Fldigi such as verified file transfer and message passing. Interconnection between these programs and the Fldigi modem is made over TCP/IP port 7322.{{cite web|url=http://www.w1hkj.com/|title=W1HKJ Software|website=www.w1hkj.com}}

Some of the Suite are however standalone programs used for utility or testing purposes only, with no connection to the Fldigi main modem.

Flamp implements the Amateur Multicast Protocol by Dave Freese, W1HKJ[http://www.w1hkj.com/files/flamp/Amp-2.V3.0.Protocol.pdf FLAMP Amateur Multicast Protocol 3.0] w1hkj.com and is a tool for connectionless transferring of files to multiple users simultaneously without requiring any existing infrastructure. The program breaks a given file into multiple smaller pieces, checksums each piece, then transmits each piece one or more times. When all parts are correctly received the sent file is re-assembled and can be saved by receiving stations.{{cite web|url=http://www.w1hkj.com/flamp2.1-help/index.html|title=FLAMP Users Manual: FLAMP Users Manual - Version 2.1.02|website=www.w1hkj.com}} This program is useful for multicasting files over lossy connections such as those found on High frequency (HF) or during emergency communications.

Flarq implements the ARQ specification developed by Paul Schmidt, K9PS{{Cite web |url=http://www.w1hkj.com/FlarqHelpFiles/aux/ARQ2.pdf |title=A Proposal For An ARQ Protocol For Use With MT63 And Similar Modes |last =Schmidt |first=Paul L |date=December 2004 |publisher=W1HKJ |access-date=2017-08-12 }} to transfer emails, text files, images, and binary files over radio. This protocol is unicast and connection-based. The software seamlessly integrates with existing email clients such as Microsoft Outlook, Mozilla Thunderbird, and Sylpheed.{{cite web|url=http://www.w1hkj.com/FlarqHelpFiles/|title=flarqhelp main|author=Dave Freese|website=www.w1hkj.com}}

Flmsg allows users to send, receive, edit, and create pre-formatted forms. Such a system speeds the flow of information during emergency communications. The software has a number of forms built-in including FEMA ICS forms, MARS reports & messages, Hospital ICS forms, Red Cross messages, IARU and NTS messages.{{cite web|url=http://www.w1hkj.com/flmsg-help/|title=FLMSG Users Manual: FLMSG Users Manual - Version 4.0|website=www.w1hkj.com}}

Flwrap is a tool for the sending of files using a simplified drag and drop interface. Data compression is available also, which reduces data transfer times.{{cite web|url=http://www.w1hkj.com/Flwrap/|title=FLWRAP Users Manual: FLWRAP Users Manual - Version 1.3|website=www.w1hkj.com}}

FLNet assists net control operators in keeping track of multiple stations during digital amateur radio nets.[https://sourceforge.net/projects/fldigi/files/flnet/ FLNet] sourceforge.net

FLLog is a logging software which keeps track of conversations between amateur radio operators in a database format known as ADIF.{{Cite web|url=https://sourceforge.net/projects/fldigi/files/fllog/|title=fldigi - Browse /fllog at SourceForge.net|website=sourceforge.net}}

FLWkey is a simple interface to control an external piece of hardware called a Winkeyer.{{Cite web|url=https://www.k1elsystems.com/|title=K1EL Systems - CW Contest Keyers for Amateur Radio|website=www.k1elsystems.com}} This is a Morse code keyer which is adjustable via computer commands over USB.{{Cite web|url=https://sourceforge.net/projects/fldigi/files/flwkey/|title=fldigi - Browse /flwkey at SourceForge.net|website=sourceforge.net}}

This is a telnet client to remote DX cluster servers, which is a real-time reporting of stations heard transmitting, and their frequencies. It does not connect to Fldigi.[https://sourceforge.net/projects/fldigi/files/flcluster/ Flcluster] sourceforge.net

Flaa is a control program for use with the RigExpert AA-xxxx series of antenna analyzers, and does not connect to Fldigi.[https://sourceforge.net/projects/fldigi/files/flaa/ Flaa] sourceforge.net

FLRig is a component of the FLDigi suite of applications that enables computer aided control of various radios using a serial or USB connection.{{Cite web|url=https://sourceforge.net/projects/fldigi/files/flrig/|title=fldigi - Browse /flrig at SourceForge.net|website=sourceforge.net}}

Using FLRig in combination with FLDigi, events such as frequency, power level, receiver gain and audio gain may be adjusted from the computer automatically or by user intervention.

The Fldigi development group also releases a number of open-source programs which assist in the testing, development, and comparison of different modes within Fldigi, such as LinSim, CompText, and CompTTY.

To identify the mode being transmitted a signal called an RSID, or Reed-Solomon Identifier, can be transmitted before the data. Using this identifier the receiving software can automatically switch to the proper mode for decoding. The assigning of these identifiers to new modes is coordinated to ensure inter-operation between programs.{{cite web | last=Freese | first=David | title=Reed-Solomon Identification| website=w1hkj.com | url=http://www.w1hkj.com/RSID_description.html | access-date=3 January 2024}} Currently 7 sound card-digital-modem programs support this standard:

• PocketDigi
• FDMDV
• DM780
• Multipsk
• Fldigi
• AndFlmsg
• TIVAR

RSID operates by sending a short burst of a specific modulation before the data signal, which can be used to automatically identify over 272 digital modes. This burst consists of a 10.766 baud 16-tone MFSK modulation where 15 tones/symbols are sent. The burst occupies 172 Hz of bandwidth and lasts for 1.4 seconds.

For simple keyboard-to-keyboard communication Fldigi can be operated using just the main window. For more complex uses or file transfer external programs can be attached to the internal TCP/UDP ports 7322 (ARQ), 7342 (KISS), and 7362 (XML-RPC).

The image below helps to illustrate the interconnections and signal-flow within the Fldigi architecture.

File:FLdigi FLowchart.png

Fldigi allows external programs to attach and send / receive data by connecting to port 7322/ARQ or 7342/KISS. When used this way, Fldigi and the computer's sound card are acting as a "softmodem" allowing text or data sent on one computer to be transferred using the wireless radio link in-between.

Programs which have a history of use with Fldigi as the underlying modem include:

• D-Rats - easy to use chatrooms, email, and file transfer over-radio.
• PSKmail - send and receive on-internet e-mail over a remote radio connection.
• Fldigiattach - attach Fldigi as modem for Linux AX.25 and TCP/IP connections.
• UIChat - Java-based amateur radio chat program.
• LinkUP - Program for unattended operation and person to person chat.
• Linux - Fldigi can be used in Linux as a KISS (TNC) modem for AX.25 and TCP/IP connections.

• At the 2014 Dayton Hamvention the project lead, Dave Freese (W1HKJ), was recognized with the Technical Excellence Award "for his development and distribution of the Fast Light Digital Modem Application (fldigi) family of programs for use in amateur and emergency communications."{{cite web|url=http://www.arrl.org/news/dayton-hamvention-announces-2014-award-winners|title=Dayton Hamvention® Announces 2014 Award Winners|website=www.arrl.org}}
• Fldigi was selected as SourceForge's June 2017 Staff 'Project of the Month'{{cite web|url=https://sourceforge.net/blog/june-2017-staff-pick-project-of-the-month-fldigi/|title=June 2017, "Staff Pick" Project of the Month – fldigi - SourceForge Community Blog|date=5 June 2017|website=sourceforge.net}}
• Fldigi was one of SourceForge's 'Projects of the Week' for Oct 17, 2016{{cite web|url=https://sourceforge.net/blog/projects-of-the-week-october-17-2016/|title=Projects of the Week, October 17, 2016 - SourceForge Community Blog|date=17 October 2016|website=sourceforge.net}}
• Fldigi was selected as SourceForge's December 2017 Community Choice 'Project of the Month'{{cite web|url=https://sourceforge.net/blog/december-2017-community-choice-project-month-fldigi/|title=December 2017, "Community Choice" Project of the Month – fldigi - SourceForge Community Blog|date=1 December 2017|website=sourceforge.net}}

The software is also utilized by some organizations for both routine and disaster/emergency relief services.

• Multiple state and county emergency operations centers{{cite web|url=http://www.arrl.org/news/big-island-ares-districts-activate-to-support-possible-hurricane-response-in-hawaii|title=Big Island ARES Districts Activate to Support Possible Hurricane Response in Hawaii|website=www.arrl.org}}{{cite web|url=http://www.wastateares.org/cascadia-rising/cascadia-comms|title=Cascadia Comms - WAEmcomm|website=www.wastateares.org|archive-url=https://web.archive.org/web/20210622193537/http://www.wastateares.org/cascadia-rising/cascadia-comms|archive-date=2021-06-22|url-status=dead}}
• W1AW (ARRL){{cite web|url=http://www.kb6nu.com/w1hkj-honored-for-fldigi/|title=W1HKJ honored for fldigi - KB6NU's Ham Radio Blog|date=22 August 2012|website=kb6nu.com}}
• Amateur Radio Emergency Service (ARES){{cite web|url=http://www.w9tca.com/w9tca/NBEMS|title=NBEMS (fldigi, flarq, etc.) - Tippecanoe County ARES - W9TCA.com|website=www.w9tca.com|archive-url=https://web.archive.org/web/20190622085520/http://www.w9tca.com/w9tca/NBEMS|archive-date=2019-06-22|url-status=dead}}
• Radio Amateur Civil Emergency Service (RACES){{cite web|url=http://groupspaces.com/BCARES/pages/fldigi-and-nbems|title=Join Brown County ARES/RACES : Brown County ARES/RACES : GroupSpaces|website=groupspaces.com}}
• Civil Air Patrol (CAP){{cite web|url=https://www.capmembers.com/emergency_services/communications-blog/?new_on_hf_code_group_messages&show=entry&blogID=1407|title=New on HF: Code Group Messages|work=Communications Blog - Civil Air Patrol National Headquarters|archive-url=https://web.archive.org/web/20160915213114/https://www.capmembers.com/emergency_services/communications-blog/?new_on_hf_code_group_messages&show=entry&blogID=1407|archive-date=2016-09-15|url-status=dead}}
• SATERN, the Salvation Army Team Emergency Radio Network{{cite web|url=http://qso.com/satern/training/NBEMS.html|title=FLDIGI NBEMS Intro|website=SATERN - Salvation Army Team Emergency Radio Network|archive-url=https://web.archive.org/web/20181016063310/http://qso.com/satern/training/NBEMS.html|archive-date=2018-10-16|url-status=dead}}
• SKYWARN a program of the United States' National Weather Service (NWS) whose mission is to collect reports of localized severe weather.[https://www.skywarnforum.com/threads/hawaii-skywarn-net-activation.23582/ Hawaii skywarn net activation] skywarnforum.com {{dead link|date=January 2018}}

Following the successful tests by the Voice of America's VOA Radiogram program, international and government shortwave broadcasters began testing and experimenting with digital data over shortwave broadcast channels using the Fldigi software.{{cite web|url=http://www.radioworld.com/article/international-broadcasters-reconsider-shortwave/271847|title=International Broadcasters Reconsider Shortwave|last=RWO|website=radioworld.com}}

These tests led to regular weekly digital broadcasts by the broadcasters listed below.

• VOA Radiogram, service terminated in 2017 and continuing as Shortwave Radiogram.
• In June 2017, following the demise of VOA Radiogram, [http://swradiogram.net/ Shortwave Radiogram] began broadcasting digital data-streams using Fldigi via WRMI in Miami and Space Line [http://www.spaceline.bg/ Spaceline Bulgaria - Broadcasting Airtime on shortwave, satellite and internet] in Bulgaria.{{cite web |url=http://swradiogram.net/ |title=Shortwave Radiogram}}
• Radio Havana Cuba
• Radio Moscow
• Radio Australia{{cite web|url=http://swling.com/blog/2013/06/radio-australia-transmitting-digital-radiograms-this-weekend-june-8-9/|title=Radio Australia transmitting digital radiograms this weekend, June 8 – 9|date=6 June 2013|website=swling.com}}
• Radio Miami International
• Italian Broadcasting Corporation{{cite web|url=http://voaradiogram.net/post/148501070787/voa-radiogram-6-7-august-2016-in-thor25x4-news|title=VOA Radiogram, 6-7 August 2016: In Thor25x4, news about Io|website=VOA Radiogram}}
• WBCQ (SW){{cite web|url=http://swling.com/blog/2012/05/decoding-wbcqs-digital-message/|title=How to decode WBCQ's digital message|date=5 May 2012|website=swling.com}}
• Mighty KBC{{cite web|url=http://swling.com/blog/2012/11/the-mighty-kbc-tests-9450-khz-and-will-send-a-digital-message-this-weekend/|title=The Mighty KBC tests 9,450 kHz and will send a digital message this weekend|date=6 November 2012|website=swling.com}}

The Fldigi suite of programs has become popular within the U.S. Army and U.S. Air Force Military Auxiliary Radio System.{{cite web|url=http://www.af-mars.org/public/|title=Air Force MARS Region Ten – We provide contingent radio communications as directed by US DoD|website=www.af-mars.org}}{{Cite web |url=https://txarmymars.org/downloads/Basic-Soundcard-Training.pdf |title=Basic Sound Card Mode Training Guide |last=Thompson |first=Lewis |date=2011-08-30 |publisher=Texas Army MARS |access-date=2016-08-16 |archive-url=https://web.archive.org/web/20160821174445/https://txarmymars.org/downloads/Basic-Soundcard-Training.pdf |archive-date=2016-08-21 |url-status=dead }}

Fldigi is being used in-testing as part of the Department of Homeland Security Shares program, which utilizes "existing HF radio resources of government, critical infrastructure, and disaster response organizations to coordinate and transmit emergency messages"{{Cite web|url=https://www.cisa.gov/shares-program-information|title = SHARES Program Information | CISA}}{{Cite web|url=http://w4cae.com/dhs-shares-lf-beacon/|title = DHS Shares LF Beacon – the Columbia Amateur Radio Club}}

Fldigi is used as the underlying modem for the PSKmail project.{{cite web|url=http://pskmail.org/|title=PSKmail|website=pskmail.org}} PSK Mail allows users to retrieve and send normal emails over radio.

In 2014, the group Anonymous released a communications tool named AirChat, which used Fldigi as the underlying modem. This provided a low speed yet reliable data connection using only moderate radio hardware. The AirChat software allows for anonymous transmissions of both encrypted and unencrypted messages over unencrypted channels.{{cite web|url=http://www.ibtimes.co.uk/anonymous-airchat-aims-allow-communication-without-needing-phone-internet-access-1445888|title=Anonymous' Airchat Aims to Allow Communication Without Needing Phone or Internet Access|first=Mary-Ann|last=Russon|date=24 April 2014|website=ibtimes.co.uk}}{{cite web|url=https://www.engadget.com/2014/04/25/anonymous-airchat/|title=Anonymous' radio-based networking keeps protesters off the grid|website=engadget.com|date=25 April 2014 }}{{Cite web|url=http://hplusmagazine.com/2014/05/14/airchat-secure-wireless-from-anonymous/|title=AirChat: Secure Wireless from Anonymous|date=14 May 2014|archive-url=https://web.archive.org/web/20230405074858/http://hplusmagazine.com/2014/05/14/airchat-secure-wireless-from-anonymous/|archive-date=2023-04-05|url-status=dead}}

The broadcasts listed below are transmitted on a regular schedule and can be decoded using Fldigi.

• SITOR text forecasts and storm warnings{{cite web |title=Marine Weather Broadcasts from the USCG |url=https://www.weather.gov/marine/uscg_broadcasts |publisher=National Weather Service |access-date=18 March 2024}}
• WEFAX visual weather fax{{cite web|url=http://www.nws.noaa.gov/om/marine/rfax.pdf |title=Worldwide Marine Radiofacsimile Broadcast Schedules |publisher=National Weather Service |date=2019-04-11 |archive-url=https://web.archive.org/web/20191003134025/https://www.nws.noaa.gov/om/marine/rfax.pdf |archive-date=2019-10-03 |url-status=dead}}
• SYNOP surface synoptic observations{{cite web |title=SYNOP decoding |url=http://www.w1hkj.com/FldigiHelp/synop_page.html |publisher=W1HKJ |work=Fldigi Users Manual}}
• NAVTEX warnings, forecasts, and safety information broadcasts
• VOA Radiogram Broadcasts
• W1AW Broadcasts

• Amateur radio
• Shortwave radio
• WSPR (amateur radio software)
• WSJT (amateur radio software)
• CW Skimmer
• Internet Radio Linking Project
• PSK31
• RTTY
• American Radio Relay League

{{Reflist|30em}}

• {{official website}}

{{Digital modes}}

Category:Quantized radio modulation modes

Category:Amateur radio software

Category:Amateur radio software for Linux

Category:Amateur radio software for Windows

Category:Free communication software

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