RadioLibSmol/src/protocols/RTTY/RTTY.h

#if !defined(_RADIOLIB_RTTY_H)
#define _RADIOLIB_RTTY_H

#include "../../TypeDef.h"

#if !defined(RADIOLIB_EXCLUDE_RTTY)

#include "../PhysicalLayer/PhysicalLayer.h"
#include "../AFSK/AFSK.h"

#define RADIOLIB_ITA2_FIGS                                      0x1B
#define RADIOLIB_ITA2_LTRS                                      0x1F
#define RADIOLIB_ITA2_LENGTH                                    32

// ITA2 character table: - position in array corresponds to 5-bit ITA2 code
//                       - characters to the left are in letters shift, characters to the right in figures shift
//                       - characters marked 0x7F do not have ASCII equivalent
static const char ITA2Table[RADIOLIB_ITA2_LENGTH][2] RADIOLIB_NONVOLATILE = {{'\0', '\0'}, {'E', '3'}, {'\n', '\n'}, {'A', '-'}, {' ', ' '}, {'S', '\''}, {'I', '8'}, {'U', '7'},
                                                                             {'\r', '\r'}, {'D', 0x05}, {'R', '4'}, {'J', '\a'}, {'N', ','}, {'F', '!'}, {'C', ':'}, {'K', '('},
                                                                             {'T', '5'}, {'Z', '+'}, {'L', ')'}, {'W', '2'}, {'H', 0x7F}, {'Y', '6'}, {'P', '0'}, {'Q', '1'},
                                                                             {'O', '9'}, {'B', '?'}, {'G', '&'}, {0x7F, 0x7F}, {'M', '.'}, {'X', '/'}, {'V', ';'}, {0x7F, 0x7F}};

/*!
  \class ITA2String

  \brief ITA2-encoded string.
*/
class ITA2String {
  public:
    /*!
      \brief Default single-character constructor.

      \param c ASCII-encoded character to encode as ITA2.
    */
    explicit ITA2String(char c);

    /*!
      \brief Default string constructor.

      \param str ASCII-encoded string to encode as ITA2.
    */
    explicit ITA2String(const char* str);

    /*!
      \brief Default destructor.
    */
    ~ITA2String();

    /*!
      \brief Gets the length of the ITA2 string. This number is not the same as the length of ASCII-encoded string!

      \returns Length of ITA2-encoded string.
    */
    size_t length();

    /*!
      \brief Gets the ITA2 representation of the ASCII string set in constructor.

      \returns Pointer to dynamically allocated array, which contains ITA2-encoded bytes.
      It is the caller's responsibility to deallocate this memory!
    */
    uint8_t* byteArr();

#if !defined(RADIOLIB_GODMODE)
  private:
#endif
    #if defined(RADIOLIB_STATIC_ONLY)
      char _str[RADIOLIB_STATIC_ARRAY_SIZE];
    #else
      char* _str;
    #endif
    size_t _len;
    size_t _ita2Len;

    static uint16_t getBits(char c);
};

// supported encoding schemes
#define RADIOLIB_ASCII                                          0
#define RADIOLIB_ASCII_EXTENDED                                 1
#define RADIOLIB_ITA2                                           2

/*!
  \class RTTYClient

  \brief Client for RTTY communication. The public interface is the same as Arduino Serial.
*/
class RTTYClient {
  public:
    /*!
      \brief Constructor for 2-FSK mode.

      \param phy Pointer to the wireless module providing PhysicalLayer communication.
    */
    explicit RTTYClient(PhysicalLayer* phy);

    #if !defined(RADIOLIB_EXCLUDE_AFSK)
    /*!
      \brief Constructor for AFSK mode.

      \param audio Pointer to the AFSK instance providing audio.
    */
    explicit RTTYClient(AFSKClient* audio);
    #endif

    // basic methods

    /*!
      \brief Initialization method.

      \param base Base (space) frequency to be used in MHz (in 2-FSK mode), or the space tone frequency in Hz (in AFSK mode)

      \param shift Frequency shift between mark and space in Hz.

      \param rate Baud rate to be used during transmission.

      \param encoding Encoding to be used. Defaults to ASCII.

      \param stopBits Number of stop bits to be used.

      \returns \ref status_codes
    */
    int16_t begin(float base, uint32_t shift, uint16_t rate, uint8_t encoding = RADIOLIB_ASCII, uint8_t stopBits = 1);

    /*!
      \brief Send out idle condition (RF tone at mark frequency).
    */
    void idle();

    /*!
      \brief Stops transmitting.

      \returns \ref status_codes
    */
    int16_t standby();

    size_t write(const char* str);
    size_t write(uint8_t* buff, size_t len);
    size_t write(uint8_t b);

    #if defined(RADIOLIB_BUILD_ARDUINO)
    size_t print(__FlashStringHelper*);
    size_t print(const String &);
    #endif
    size_t print(ITA2String &);
    size_t print(const char[]);
    size_t print(char);
    size_t print(unsigned char, int = DEC);
    size_t print(int, int = DEC);
    size_t print(unsigned int, int = DEC);
    size_t print(long, int = DEC);
    size_t print(unsigned long, int = DEC);
    size_t print(double, int = 2);

    size_t println(void);
    #if defined(RADIOLIB_BUILD_ARDUINO)
    size_t println(__FlashStringHelper*);
    size_t println(const String &);
    #endif
    size_t println(ITA2String &);
    size_t println(const char[]);
    size_t println(char);
    size_t println(unsigned char, int = DEC);
    size_t println(int, int = DEC);
    size_t println(unsigned int, int = DEC);
    size_t println(long, int = DEC);
    size_t println(unsigned long, int = DEC);
    size_t println(double, int = 2);

#if !defined(RADIOLIB_GODMODE)
  private:
#endif
    PhysicalLayer* _phy;
    #if !defined(RADIOLIB_EXCLUDE_AFSK)
    AFSKClient* _audio;
    #endif

    uint8_t _encoding = RADIOLIB_ASCII;
    uint32_t _base = 0, _baseHz = 0;
    uint32_t _shift = 0, _shiftHz = 0;
    uint32_t _bitDuration = 0;
    uint8_t _dataBits = 0;
    uint8_t _stopBits = 0;

    void mark();
    void space();

    size_t printNumber(unsigned long, uint8_t);
    size_t printFloat(double, uint8_t);

    int16_t transmitDirect(uint32_t freq = 0, uint32_t freqHz = 0);
};

#endif

#endif