Implemented promiscuous mode for CC1101 and RF69

src/modules/CC1101.cpp

@@ -4,6 +4,8 @@ CC1101::CC1101(Module* module) : PhysicalLayer(CC1101_CRYSTAL_FREQ, CC1101_DIV_E
   _mod = module;
   _packetLengthQueried = false;
   _packetLengthConfig = CC1101_LENGTH_CONFIG_VARIABLE;
+
+  _syncWordLength = CC1101_DEFAULT_SYNC_WORD_LENGTH;
 }
 
 int16_t CC1101::begin(float freq, float br, float rxBw, float freqDev, int8_t power) {
@@ -441,13 +443,37 @@ int16_t CC1101::setOutputPower(int8_t power) {
   return(SPIsetRegValue(CC1101_REG_PATABLE, powerRaw));
 }
 
-int16_t CC1101::setSyncWord(uint8_t syncH, uint8_t syncL) {
+int16_t CC1101::setSyncWord(uint8_t* syncWord, uint8_t len, uint8_t maxErrBits) {
-  // set sync word
+  if(maxErrBits > 1) {
-  int16_t state = SPIsetRegValue(CC1101_REG_SYNC1, syncH);
+    return(ERR_INVALID_SYNC_WORD);
-  state |= SPIsetRegValue(CC1101_REG_SYNC0, syncL);
+  }
+
+  // sync word must not contain value 0x00
+  for(uint8_t i = 0; i < len; i++) {
+    if(syncWord[i] == 0x00) {
+      return(ERR_INVALID_SYNC_WORD);
+    }
+  }
+
+  _syncWordLength = len;
+
+  // enable sync word filtering
+  int16_t state = enableSyncWordFiltering(maxErrBits);
+  if (state != ERR_NONE) {
     return(state);
   }
 
+  // set sync word register
+  _mod->SPIwriteRegisterBurst(CC1101_REG_SYNC1, syncWord, len);
+
+  return(ERR_NONE);
+}
+
+int16_t CC1101::setSyncWord(uint8_t syncH, uint8_t syncL, uint8_t maxErrBits) {
+  uint8_t syncWord[] = { syncH, syncL };
+  return(setSyncWord(syncWord, sizeof(syncWord), maxErrBits));
+}
+
 int16_t CC1101::setNodeAddress(uint8_t nodeAddr, uint8_t numBroadcastAddrs) {
   if(!(numBroadcastAddrs > 0) && (numBroadcastAddrs <= 2)) {
     return(ERR_INVALID_NUM_BROAD_ADDRS);
@@ -547,6 +573,76 @@ int16_t CC1101::variablePacketLengthMode(uint8_t maxLen) {
   return(state);
 }
 
+int16_t CC1101::enableSyncWordFiltering(uint8_t maxErrBits) {
+  if (maxErrBits > 1) {
+    return(ERR_INVALID_SYNC_WORD);
+  }
+
+  if (maxErrBits == 0) {
+    if (_syncWordLength == 1) {
+      // in 16 bit sync word, expect all 16 bits
+      return(SPIsetRegValue(CC1101_REG_MDMCFG2, CC1101_SYNC_MODE_16_16, 2, 0));
+    } else if (_syncWordLength == 2) {
+      // there's no 32 of 32 case, so we resort to 30 of 32 bits required
+      return(SPIsetRegValue(CC1101_REG_MDMCFG2, CC1101_SYNC_MODE_30_32, 2, 0));
+    }
+  }
+
+  if (maxErrBits == 1) {
+    if (_syncWordLength == 1) {
+      // in 16 bit sync word, expect at least 15 bits
+      return(SPIsetRegValue(CC1101_REG_MDMCFG2, CC1101_SYNC_MODE_15_16, 2, 0));
+    } else if (_syncWordLength == 2) {
+      // in 32 bits sync word (16 + 16), expect 30 of 32 to match
+      return(SPIsetRegValue(CC1101_REG_MDMCFG2, CC1101_SYNC_MODE_30_32, 2, 0));
+    }
+  }
+
+  return(ERR_NONE);
+}
+
+int16_t CC1101::disableSyncWordFiltering() {
+  return(SPIsetRegValue(CC1101_REG_MDMCFG2, CC1101_SYNC_MODE_NONE, 2, 0));
+}
+
+int16_t CC1101::enableCrcFiltering() {
+  return(SPIsetRegValue(CC1101_REG_PKTCTRL0, CC1101_CRC_ON, 2, 2));
+}
+
+int16_t CC1101::disableCrcFiltering() {
+  return(SPIsetRegValue(CC1101_REG_PKTCTRL0, CC1101_CRC_OFF, 2, 2));
+}
+
+int16_t CC1101::promiscuousMode(bool promiscuous) {
+  int16_t state = ERR_NONE;
+
+  if (_promiscuous == promiscuous) {
+    return(state);
+  }
+
+  if (promiscuous == true) {
+    // disable preamble and sync word filtering and insertion
+    state = disableSyncWordFiltering();
+    if (state != ERR_NONE) {
+      return(state);
+    }
+
+    // disable CRC filtering
+    state = disableCrcFiltering();
+  } else {
+    // enable preamble and sync word filtering and insertion
+    state = enableSyncWordFiltering();
+    if (state != ERR_NONE) {
+      return(state);
+    }
+
+    // enable CRC filtering
+    state = enableCrcFiltering();
+  }
+
+  return(state);
+}
+
 int16_t CC1101::config() {
   // enable automatic frequency synthesizer calibration
   int16_t state = SPIsetRegValue(CC1101_REG_MCSM0, CC1101_FS_AUTOCAL_IDLE_TO_RXTX, 5, 4);

src/modules/CC1101.h

@@ -10,6 +10,9 @@
 #define CC1101_CRYSTAL_FREQ                           26.0
 #define CC1101_DIV_EXPONENT                           16
 #define CC1101_MAX_PACKET_LENGTH                      63
+#define CC1101_MAX_SYNC_WORD_LENGTH                   2
+#define CC1101_DEFAULT_SYNC_WORD_LENGTH               2
+#define CC1101_DEFAULT_SYNC_WORD                      { 0xD3, 0x91 }
 
 // CC1101 SPI commands
 #define CC1101_CMD_READ                               0b10000000
@@ -237,7 +240,7 @@
 #define CC1101_MOD_FORMAT_MFSK                        0b01110000  //  6     4                        MFSK - only for data rates above 26 kBaud
 #define CC1101_MANCHESTER_EN_OFF                      0b00000000  //  3     3     Manchester encoding: disabled (default)
 #define CC1101_MANCHESTER_EN_ON                       0b00001000  //  3     3                          enabled
-#define CC1101_SYNC_MODE_NONE                         0b00000000  //  2     0     synchronization: no preamble sync
+#define CC1101_SYNC_MODE_NONE                         0b00000000  //  2     0     synchronization: no preamble/sync
 #define CC1101_SYNC_MODE_15_16                        0b00000001  //  2     0                      15/16 sync word bits
 #define CC1101_SYNC_MODE_16_16                        0b00000010  //  2     0                      16/16 sync word bits (default)
 #define CC1101_SYNC_MODE_30_32                        0b00000011  //  2     0                      30/32 sync word bits
@@ -694,9 +697,24 @@ class CC1101: public PhysicalLayer {
 
       \param syncL LSB of the sync word.
 
+      \param maxErrBits Maximum allowed number of bit errors in received sync word. Defaults to 0.
+
       \returns \ref status_codes
     */
-    int16_t setSyncWord(uint8_t syncH, uint8_t syncL);
+    int16_t setSyncWord(uint8_t syncH, uint8_t syncL, uint8_t maxErrBits = 0);
+
+    /*!
+      \brief Sets 1 or 2 bytes of sync word.
+
+      \param syncWord Pointer to the array of sync word bytes.
+
+      \param len Sync word length in bytes.
+
+      \param maxErrBits Maximum allowed number of bit errors in received sync word. Defaults to 0.
+
+      \returns \ref status_codes
+    */
+    int16_t setSyncWord(uint8_t* syncWord, uint8_t len, uint8_t maxErrBits = 0);
 
     /*!
       \brief Sets node and broadcast addresses. Calling this method will also enable address filtering.
@@ -757,6 +775,45 @@ class CC1101: public PhysicalLayer {
     */
     int16_t variablePacketLengthMode(uint8_t maxLen = CC1101_MAX_PACKET_LENGTH);
 
+     /*!
+      \brief Enable sync word filtering and generation.
+
+      \param len Size of sync word (1 or 2 bytes).
+
+      \returns \ref status_codes
+    */
+    int16_t enableSyncWordFiltering(uint8_t len = CC1101_DEFAULT_SYNC_WORD_LENGTH);
+
+     /*!
+      \brief Disable preamble and sync word filtering and generation.
+
+      \returns \ref status_codes
+    */
+    int16_t disableSyncWordFiltering();
+
+     /*!
+      \brief Enable CRC filtering and generation.
+
+      \returns \ref status_codes
+    */
+    int16_t enableCrcFiltering();
+
+     /*!
+      \brief Disable CRC filtering and generation.
+
+      \returns \ref status_codes
+    */
+    int16_t disableCrcFiltering();
+
+     /*!
+      \brief Set modem in "sniff" mode: no packet filtering (e.g., no preamble, sync word, address, CRC).
+
+      \param promiscuous Set or unset promiscuous mode.
+
+      \returns \ref status_codes
+    */
+    int16_t promiscuousMode(bool promiscuous = true);
+
   private:
     Module* _mod;
 
@@ -768,6 +825,10 @@ class CC1101: public PhysicalLayer {
     bool _packetLengthQueried;
     uint8_t _packetLengthConfig;
 
+    bool _promiscuous;
+
+    uint8_t _syncWordLength;
+
     int16_t config();
     int16_t directMode();
     void getExpMant(float target, uint16_t mantOffset, uint8_t divExp, uint8_t expMax, uint8_t& exp, uint8_t& mant);

src/modules/RF69.cpp

@@ -3,8 +3,13 @@
 RF69::RF69(Module* module) : PhysicalLayer(RF69_CRYSTAL_FREQ, RF69_DIV_EXPONENT, RF69_MAX_PACKET_LENGTH)  {
   _mod = module;
   _tempOffset = 0;
+
   _packetLengthQueried = false;
   _packetLengthConfig = RF69_PACKET_FORMAT_VARIABLE;
+
+  _promiscuous = false;
+
+  _syncWordLength = RF69_DEFAULT_SYNC_WORD_LENGTH;
 }
 
 int16_t RF69::begin(float freq, float br, float rxBw, float freqDev, int8_t power) {
@@ -87,8 +92,8 @@ int16_t RF69::begin(float freq, float br, float rxBw, float freqDev, int8_t powe
   }
 
   // default sync word values 0x2D01 is the same as the default in LowPowerLab RFM69 library
-  uint8_t syncWord[] = {0x2D, 0x01};
+  uint8_t syncWord[] = RF69_DEFAULT_SYNC_WORD;
-  state = setSyncWord(syncWord, 2);
+  state = setSyncWord(syncWord, sizeof(syncWord));
   if(state != ERR_NONE) {
     return(state);
   }
@@ -495,7 +500,7 @@ int16_t RF69::setOutputPower(int8_t power) {
 
 int16_t RF69::setSyncWord(uint8_t* syncWord, size_t len, uint8_t maxErrBits) {
   // check constraints
-  if((maxErrBits > 7) || (len > 8)) {
+  if((maxErrBits > 7) || (len > RF69_MAX_SYNC_WORD_LENGTH)) {
     return(ERR_INVALID_SYNC_WORD);
   }
 
@@ -506,13 +511,14 @@ int16_t RF69::setSyncWord(uint8_t* syncWord, size_t len, uint8_t maxErrBits) {
     }
   }
 
-  // enable sync word recognition
+  _syncWordLength = len;
-  int16_t state = _mod->SPIsetRegValue(RF69_REG_SYNC_CONFIG, RF69_SYNC_ON | RF69_FIFO_FILL_CONDITION_SYNC | (len - 1) << 3 | maxErrBits, 7, 0);
+
+  int16_t state = enableSyncWordFiltering(maxErrBits);
   if (state != ERR_NONE) {
     return(state);
   }
 
-  // set sync word
+  // set sync word register
   _mod->SPIwriteRegisterBurst(RF69_REG_SYNC_VALUE_1, syncWord, len);
   return(ERR_NONE);
 }
@@ -636,6 +642,71 @@ int16_t RF69::variablePacketLengthMode(uint8_t maxLen) {
   return(state);
 }
 
+int16_t RF69::enableSyncWordFiltering(uint8_t maxErrBits) {
+  // enable sync word recognition
+  int16_t state = _mod->SPIsetRegValue(RF69_REG_SYNC_CONFIG, RF69_SYNC_ON | RF69_FIFO_FILL_CONDITION_SYNC | (_syncWordLength - 1) << 3 | maxErrBits, 7, 0);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+
+  return(state);
+}
+
+int16_t RF69::disableSyncWordFiltering() {
+  // disable preamble detection and generation
+  int16_t state = _mod->SPIsetRegValue(RF69_REG_PREAMBLE_LSB, 0, 7, 0);
+  state |= _mod->SPIsetRegValue(RF69_REG_PREAMBLE_MSB, 0, 7, 0);
+  if (state != ERR_NONE) {
+    return(state);
+  }
+
+  // disable sync word detection and generation
+  state = _mod->SPIsetRegValue(RF69_REG_SYNC_CONFIG, RF69_SYNC_OFF | RF69_FIFO_FILL_CONDITION, 7, 6);
+  if (state != ERR_NONE) {
+    return(state);
+  }
+
+  return(state);
+}
+
+int16_t RF69::enableCrcFiltering() {
+  return(_mod->SPIsetRegValue(RF69_REG_PACKET_CONFIG_1, RF69_CRC_ON), 4, 4);
+}
+
+int16_t RF69::disableCrcFiltering() {
+  return(_mod->SPIsetRegValue(RF69_REG_PACKET_CONFIG_1, RF69_CRC_OFF), 4, 4);
+}
+
+int16_t RF69::promiscuousMode(bool promiscuous) {
+  int16_t state = ERR_NONE;
+
+  if (_promiscuous == promiscuous) {
+    return(state);
+  }
+
+  if (promiscuous == true) {
+    // disable preamble and sync word filtering and insertion
+    state = disableSyncWordFiltering();
+    if (state != ERR_NONE) {
+      return(state);
+    }
+
+    // disable CRC filtering
+    state = disableCrcFiltering();
+  } else {
+    // enable preamble and sync word filtering and insertion
+    state = enableSyncWordFiltering();
+    if (state != ERR_NONE) {
+      return(state);
+    }
+
+    // enable CRC filtering
+    state = enableCrcFiltering();
+  }
+
+  return(state);
+}
+
 int16_t RF69::config() {
   int16_t state = ERR_NONE;
 

src/modules/RF69.h

@@ -10,6 +10,10 @@
 #define RF69_CRYSTAL_FREQ                             32.0
 #define RF69_DIV_EXPONENT                             19
 #define RF69_MAX_PACKET_LENGTH                        64
+#define RF69_MAX_PREAMBLE_LENGTH                      4
+#define RF69_MAX_SYNC_WORD_LENGTH                     8
+#define RF69_DEFAULT_SYNC_WORD_LENGTH                 2
+#define RF69_DEFAULT_SYNC_WORD                        { 0x2D, 0x01 }
 
 // RF69 register map
 #define RF69_REG_FIFO                                 0x00
@@ -646,7 +650,7 @@ class RF69: public PhysicalLayer {
     int16_t setOutputPower(int8_t power);
 
     /*!
-      \brief Sets sync word. Up to 8 bytes can be set as snyc word.
+      \brief Sets sync word. Up to 8 bytes can be set as sync word.
 
       \param syncWord Pointer to the array of sync word bytes.
 
@@ -724,6 +728,45 @@ class RF69: public PhysicalLayer {
     */
     int16_t variablePacketLengthMode(uint8_t maxLen = RF69_MAX_PACKET_LENGTH);
 
+     /*!
+      \brief Enable sync word filtering and generation.
+
+      \param numBits Sync word length in bits.
+
+      \returns \ref status_codes
+    */
+    int16_t enableSyncWordFiltering(uint8_t numBits = 16);
+
+     /*!
+      \brief Disable preamble and sync word filtering and generation.
+
+      \returns \ref status_codes
+    */
+    int16_t disableSyncWordFiltering();
+
+     /*!
+      \brief Enable CRC filtering and generation.
+
+      \returns \ref status_codes
+    */
+    int16_t enableCrcFiltering();
+
+     /*!
+      \brief Disable CRC filtering and generation.
+
+      \returns \ref status_codes
+    */
+    int16_t disableCrcFiltering();
+
+     /*!
+      \brief Set modem in "sniff" mode: no packet filtering (e.g., no preamble, sync word, address, CRC).
+
+      \param promiscuous Set or unset promiscuous mode.
+
+      \returns \ref status_codes
+    */
+    int16_t promiscuousMode(bool promiscuous = true);
+
   protected:
     Module* _mod;
 
@@ -735,6 +778,10 @@ class RF69: public PhysicalLayer {
     bool _packetLengthQueried;
     uint8_t _packetLengthConfig;
 
+    bool _promiscuous;
+
+    uint8_t _syncWordLength;
+
     int16_t config();
     int16_t directMode();