AX25.h

#if !defined(_RADIOLIB_RADIOLIB_AX25_H)
#define _RADIOLIB_RADIOLIB_AX25_H
 
#include "../../TypeDef.h"
 
#if !defined(RADIOLIB_EXCLUDE_AX25)
 
#include "../PhysicalLayer/PhysicalLayer.h"
#include "../AFSK/AFSK.h"
 
// macros to access bits in byte array, from http://www.mathcs.emory.edu/~cheung/Courses/255/Syllabus/1-C-intro/bit-array.html
#define SET_BIT_IN_ARRAY(A, k)                                  ( A[(k/8)] |= (1 << (k%8)) )
#define CLEAR_BIT_IN_ARRAY(A, k)                                ( A[(k/8)] &= ~(1 << (k%8)) )
#define TEST_BIT_IN_ARRAY(A, k)                                 ( A[(k/8)] & (1 << (k%8)) )
#define GET_BIT_IN_ARRAY(A, k)                                  ( (A[(k/8)] & (1 << (k%8))) ? 1 : 0 )
 
// CRC-CCITT calculation macros
#define XOR(A, B)                                               ( ((A) || (B)) && !((A) && (B)) )
#define CRC_CCITT_POLY                                          0x1021      //  generator polynomial
#define CRC_CCITT_POLY_REVERSED                                 0x8408      //  CRC_CCITT_POLY in reversed bit order
#define CRC_CCITT_INIT                                          0xFFFF      //  initial value
 
// maximum callsign length in bytes
#define RADIOLIB_AX25_MAX_CALLSIGN_LEN                          6
 
// flag field                                                         MSB   LSB   DESCRIPTION
#define RADIOLIB_AX25_FLAG                                      0b01111110  //  7     0     AX.25 frame start/end flag
 
// address field
#define RADIOLIB_AX25_SSID_COMMAND_DEST                         0b10000000  //  7     7     frame type: command (set in destination SSID)
#define RADIOLIB_AX25_SSID_COMMAND_SOURCE                       0b00000000  //  7     7                 command (set in source SSID)
#define RADIOLIB_AX25_SSID_RESPONSE_DEST                        0b00000000  //  7     7                 response (set in destination SSID)
#define RADIOLIB_AX25_SSID_RESPONSE_SOURCE                      0b10000000  //  7     7                 response (set in source SSID)
#define RADIOLIB_AX25_SSID_HAS_NOT_BEEN_REPEATED                0b00000000  //  7     7                 not repeated yet (set in repeater SSID)
#define RADIOLIB_AX25_SSID_HAS_BEEN_REPEATED                    0b10000000  //  7     7                 repeated (set in repeater SSID)
#define RADIOLIB_AX25_SSID_RESERVED_BITS                        0b01100000  //  6     5     reserved bits in SSID
#define RADIOLIB_AX25_SSID_HDLC_EXTENSION_CONTINUE              0b00000000  //  0     0     HDLC extension bit: next octet contains more address information
#define RADIOLIB_AX25_SSID_HDLC_EXTENSION_END                   0b00000001  //  0     0                         address field end
 
// control field
#define RADIOLIB_AX25_CONTROL_U_SET_ASYNC_BAL_MODE              0b01101100  //  7     2     U frame type: set asynchronous balanced mode (connect request)
#define RADIOLIB_AX25_CONTROL_U_SET_ASYNC_BAL_MODE_EXT          0b00101100  //  7     2                   set asynchronous balanced mode extended (connect request with module 128)
#define RADIOLIB_AX25_CONTROL_U_DISCONNECT                      0b01000000  //  7     2                   disconnect request
#define RADIOLIB_AX25_CONTROL_U_DISCONNECT_MODE                 0b00001100  //  7     2                   disconnect mode (system busy or disconnected)
#define RADIOLIB_AX25_CONTROL_U_UNNUMBERED_ACK                  0b01100000  //  7     2                   unnumbered acknowledge
#define RADIOLIB_AX25_CONTROL_U_FRAME_REJECT                    0b10000100  //  7     2                   frame reject
#define RADIOLIB_AX25_CONTROL_U_UNNUMBERED_INFORMATION          0b00000000  //  7     2                   unnumbered information
#define RADIOLIB_AX25_CONTROL_U_EXHANGE_IDENTIFICATION          0b10101100  //  7     2                   exchange ID
#define RADIOLIB_AX25_CONTROL_U_TEST                            0b11100000  //  7     2                   test
#define RADIOLIB_AX25_CONTROL_POLL_FINAL_ENABLED                0b00010000  //  4     4     control field poll/final bit: enabled
#define RADIOLIB_AX25_CONTROL_POLL_FINAL_DISABLED               0b00000000  //  4     4                                   disabled
#define RADIOLIB_AX25_CONTROL_S_RECEIVE_READY                   0b00000000  //  3     2     S frame type: receive ready (system ready to receive)
#define RADIOLIB_AX25_CONTROL_S_RECEIVE_NOT_READY               0b00000100  //  3     2                   receive not ready (TNC buffer full)
#define RADIOLIB_AX25_CONTROL_S_REJECT                          0b00001000  //  3     2                   reject (out of sequence or duplicate)
#define RADIOLIB_AX25_CONTROL_S_SELECTIVE_REJECT                0b00001100  //  3     2                   selective reject (single frame repeat request)
#define RADIOLIB_AX25_CONTROL_INFORMATION_FRAME                 0b00000000  //  0     0     frame type: information (I frame)
#define RADIOLIB_AX25_CONTROL_SUPERVISORY_FRAME                 0b00000001  //  1     0                 supervisory (S frame)
#define RADIOLIB_AX25_CONTROL_UNNUMBERED_FRAME                  0b00000011  //  1     0                 unnumbered (U frame)
 
// protocol identifier field
#define RADIOLIB_AX25_PID_ISO_8208                              0x01
#define RADIOLIB_AX25_PID_TCP_IP_COMPRESSED                     0x06
#define RADIOLIB_AX25_PID_TCP_IP_UNCOMPRESSED                   0x07
#define RADIOLIB_AX25_PID_SEGMENTATION_FRAGMENT                 0x08
#define RADIOLIB_AX25_PID_TEXNET_DATAGRAM_PROTOCOL              0xC3
#define RADIOLIB_AX25_PID_LINK_QUALITY_PROTOCOL                 0xC4
#define RADIOLIB_AX25_PID_APPLETALK                             0xCA
#define RADIOLIB_AX25_PID_APPLETALK_ARP                         0xCB
#define RADIOLIB_AX25_PID_ARPA_INTERNET_PROTOCOL                0xCC
#define RADIOLIB_AX25_PID_ARPA_ADDRESS_RESOLUTION               0xCD
#define RADIOLIB_AX25_PID_FLEXNET                               0xCE
#define RADIOLIB_AX25_PID_NET_ROM                               0xCF
#define RADIOLIB_AX25_PID_NO_LAYER_3                            0xF0
#define RADIOLIB_AX25_PID_ESCAPE_CHARACTER                      0xFF
 
// AFSK tones in Hz
#define RADIOLIB_AX25_AFSK_MARK                                 1200
#define RADIOLIB_AX25_AFSK_SPACE                                2200
 
// tone duration in us (for 1200 baud AFSK)
#define RADIOLIB_AX25_AFSK_TONE_DURATION                        833
 
class AX25Frame {
  public:
    char destCallsign[RADIOLIB_AX25_MAX_CALLSIGN_LEN + 1];
 
    uint8_t destSSID;
 
    char srcCallsign[RADIOLIB_AX25_MAX_CALLSIGN_LEN + 1];
 
    uint8_t srcSSID;
 
    uint8_t numRepeaters;
 
    uint8_t control;
 
    uint8_t protocolID;
 
    uint16_t infoLen;
 
    uint8_t rcvSeqNumber;
 
    uint16_t sendSeqNumber;
 
    #if !defined(RADIOLIB_STATIC_ONLY)
 
      uint8_t* info;
 
      char** repeaterCallsigns;
 
      uint8_t* repeaterSSIDs;
    #else
 
      uint8_t info[RADIOLIB_STATIC_ARRAY_SIZE];
 
      char repeaterCallsigns[8][RADIOLIB_AX25_MAX_CALLSIGN_LEN + 1];
 
      uint8_t repeaterSSIDs[8];
    #endif
 
    AX25Frame(const char* destCallsign, uint8_t destSSID, const char* srcCallsign, uint8_t srcSSID, uint8_t control);
 
    AX25Frame(const char* destCallsign, uint8_t destSSID, const char* srcCallsign, uint8_t srcSSID, uint8_t control, uint8_t protocolID, const char* info);
 
    AX25Frame(const char* destCallsign, uint8_t destSSID, const char* srcCallsign, uint8_t srcSSID, uint8_t control, uint8_t protocolID, uint8_t* info, uint16_t infoLen);
 
    AX25Frame(const AX25Frame& frame);
 
    ~AX25Frame();
 
    AX25Frame& operator=(const AX25Frame& frame);
 
    int16_t setRepeaters(char** repeaterCallsigns, uint8_t* repeaterSSIDs, uint8_t numRepeaters);
 
    void setRecvSequence(uint8_t seqNumber);
 
    void setSendSequence(uint8_t seqNumber);
};
 
class AX25Client {
  public:
    explicit AX25Client(PhysicalLayer* phy);
 
    #if !defined(RADIOLIB_EXCLUDE_AFSK)
 
    explicit AX25Client(AFSKClient* audio);
 
    int16_t setCorrection(int16_t mark, int16_t space, float length = 1.0f);
    #endif
 
    // basic methods
 
    int16_t begin(const char* srcCallsign, uint8_t srcSSID = 0x00, uint8_t preambleLen = 8);
 
    int16_t transmit(String& str, const char* destCallsign, uint8_t destSSID = 0x00);
 
    int16_t transmit(const char* str, const char* destCallsign, uint8_t destSSID = 0x00);
 
    int16_t sendFrame(AX25Frame* frame);
 
#if !defined(RADIOLIB_GODMODE)
  private:
#endif
    friend class APRSClient;
 
    PhysicalLayer* _phy;
    #if !defined(RADIOLIB_EXCLUDE_AFSK)
    AFSKClient* _audio;
    uint32_t _afskMark;
    uint32_t _afskSpace;
    uint32_t _afskLen;
    #endif
 
    char _srcCallsign[RADIOLIB_AX25_MAX_CALLSIGN_LEN + 1] = {0, 0, 0, 0, 0, 0, 0};
    uint8_t _srcSSID = 0;
    uint16_t _preambleLen = 0;
 
    static uint16_t getFrameCheckSequence(uint8_t* buff, size_t len);
 
    void getCallsign(char* buff);
    uint8_t getSSID();
};
 
#endif
 
#endif