CCIR476 Encoder Library for Arduino

This library offers an easy way to encode and decode CCIR476 symbols on your Arduino for SITOR, AMTOR and Navtex message encoding and decoding.

Library Installation

The best way to install the library is via the Arduino Library Manager, which is available if you are using Arduino IDE version 1.6.2 or greater. To install it this way, simply go to the menu Sketch > Include Library > Manage Libraries..., and then in the search box at the upper-right, type "CCIR476". Click on the entry in the list below, then click on the provided "Install" button. By installing the library this way, you will always have notifications of future library updates, and can easily switch between library versions.

If you need to or would like to install the library the old-fashioned was, you can download a copy of the library in a ZIP file. Download a ZIP file of the library from the GitHub repository by using the "Download ZIP" button at the right of the main repository page. Extract the ZIP file, then rename the unzipped folder as "CCIR476". Finally, open the Arduino IDE, select menu Sketch > Import Library... > Add Library..., and select the renamed folder that you just downloaded. Restart the IDE and you should have access to the new library.

Hardware Requirements

This library has been written for the Arduino platform and has been successfully tested on the Arduino Uno, Arduino Nano and Arduino Mega 2560 Rev 3.

Available Functions and Constants

here is a simple example named CCIR476Example.ino that is placed in your examples menu under the CCIR476 Arduino folder.

First of all, the CCIR476.h header file need to be included and the CCIR476 class needs to be instantiated.

#include <CCIR476.h>
CCIR476 CCIR476;

After instantiating the CCIR476 class, important SITOR-A / SITOR-B control symbols are available through the following constant names:

CCIR_LETTERS    0x5A    // Letters mode control Symbol
CCIR_FIGURES    0x36    // Figures mode control Symbol
CCIR_ALPHA      0x0F    // Idle signal 'Alpha' / Phasing signal 1
CCIR_BETA       0x33    // Idle signal 'Alpha' / Phasing signal 1
CCIR_REP        0x66    // Signal repetition (RQ) / Phasing signal 2

After instantiating the CCIR476 class, there are 3 functions available:

• bool getMode();
• setMode(bool);
• bool ModeChanged(void);
• bool isLetter(char)
• int Encode(char)
• char Decode(int, bool mode)
• char Decode(int)

CCIR476.bool getMode() returns boolean '1' for letter mode, boolean '0' for figures mode.

CCIR476.bool getMode();

CCIR476.bool setMode() sets the mode of the CCIR476 class either to letters (parameter: boolean 1) or figures (parameter: boolean 0)

CCIR476.setMode(bool);

CCIR476.ModeChanged() will check if the mode (letters / figures) has changed from the last time this function was called. This is important to determine whether or not a letters / figures control symbol needs to be transmitted before sending the next symbol.

CCIR476.ModeChanged();

CCIR476.isLetter() returns a bolean 'true' if the character supplied through the function's argument is a letter. This function is necessary because CCIR476 allocates the same number twice in the corresponding look-up table; Once for a character and once for a figure. The switching between letters mode and figures mode is done by control symbols.

CCIR476.isLetter('A')

CCIR476.Encode() returns the CCIR476 encoded number corresponding to the character supplied in the function's argument.

CCIR = CCIR476.Encode('A')

CCIR476.Decode(int) returns the decoded character. If the CCIR476.Decode() funtion detects control symbols for letters (0x5A) or figures (0x36) mode, the current decoding mode for the entore class will be switched accordingly. This change can be detected by using the CCIR476.ModeChanged() function.

// Decode 0x47 ('A' in Letter mode, '-' in figures mode).
CCIR476.Decode(0x47);

// Will detect figures mode control symbol and switch the decoding mode accordingly
CCIR476.Decode(0x36);

CCIR476.Decode(int, bool mode) returns the decoded character. The first parameter passed to the function is the encoded symbol. The second parameter is true if the encoded symbol is a letter. If it is false, the figures look-up table will be used.

CCIR476.Decode(CCIR476.Encode('Z'), CCIR476.isLetter('Z'))

Links & Contact

If you have any questions or comments, feel free to contact me through the email address provided in the project files. Additionally, feel free to check out my blogs and YouTube channel for additional information, examples and feedback:

Blog (EN): https://baltic-lab.com

Blog (DE): https://baltic-labor.de/

YouTube (EN): https://www.youtube.com/c/BalticLab

Arduino Lint Status

Changelog

• v1.2.1

Added CITATION.cff

• v1.2.0

Corrected major error in the CCIR476.Encode() function: Previously, the automatic mode change did not work.

Included two new examples: NAVTEXSIMLOGICOUT.ino and NAVTEXSIMSI531.ino to show how to use the CCIR474 library to generate a 100 baud NAVTEX message on 518 kHz with prober synchronization, phasing and SITOR B forward error correction. NAVTEXSIMLOGICOUT.ino provides the space/mark signals as logic level output for use with a function generator. NAVTEXSIMSI531.ino utilizes a SI5351A to generate the rf signal without the use of a function generator.

• v1.1.0

Added control symbols and the following new functions:

bool getMode();
setMode(bool);
bool ModeChanged(void);
char Decode(int)

Added keywords.txt

• v1.0.1

  • Minor typos and style issues corrected

• v1.0.0

  • Initial release

License

CCIR476 is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

CCIR476 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with CCIR476. If not, see http://www.gnu.org/licenses/.