[SX127x] Sync with LoRaLib v7.0.0

examples/SX127x_ChannelActivityDetection/SX127x_ChannelActivityDetection.ino

@@ -7,12 +7,7 @@
    if the LoRa channel is free, or if you should start 
    receiving a message.
 
-   Other modules from SX127x family can also be used.
+   Other modules from SX127x/RFM9x family can also be used.
-   SX1272 lora = Kite.ModuleA;
-   SX1273 lora = Kite.ModuleA;
-   SX1276 lora = Kite.ModuleA;
-   SX1277 lora = Kite.ModuleA;
-   SX1279 lora = Kite.ModuleA;
 */
 
 // include the library

examples/SX127x_Receive/SX127x_Receive.ino

@@ -11,12 +11,7 @@
     - sync word
     - preamble length
 
-   Other modules from SX127x family can also be used.
+   Other modules from SX127x/RFM9x family can also be used.
-   SX1272 lora = Kite.ModuleA;
-   SX1273 lora = Kite.ModuleA;
-   SX1276 lora = Kite.ModuleA;
-   SX1277 lora = Kite.ModuleA;
-   SX1279 lora = Kite.ModuleA;
 */
 
 // include the library
@@ -73,13 +68,13 @@ void loop() {
     // print the RSSI (Received Signal Strength Indicator)
     // of the last received packet
     Serial.print("[SX1278] RSSI:\t\t");
-    Serial.print(lora.lastPacketRSSI);
+    Serial.print(lora.getRSSI());
     Serial.println(" dBm");
 
     // print the SNR (Signal-to-Noise Ratio)
     // of the last received packet
     Serial.print("[SX1278] SNR:\t\t");
-    Serial.print(lora.lastPacketSNR);
+    Serial.print(lora.getSNR());
     Serial.println(" dBm");
 
     // print frequency error

examples/SX127x_ReceiveInterrupt/SX127x_ReceiveInterrupt.ino

@@ -12,12 +12,7 @@
     - coding rate
     - sync word
 
-   Other modules from SX127x family can also be used.
+   Other modules from SX127x/RFM9x family can also be used.
-   SX1272 lora = Kite.ModuleA;
-   SX1273 lora = Kite.ModuleA;
-   SX1276 lora = Kite.ModuleA;
-   SX1277 lora = Kite.ModuleA;
-   SX1279 lora = Kite.ModuleA;
 */
 
 // include the library
@@ -124,12 +119,12 @@ void loop() {
   
       // print RSSI (Received Signal Strength Indicator) 
       Serial.print("RSSI:\t\t");
-      Serial.print(lora.lastPacketRSSI);
+      Serial.print(lora.getRSSI());
       Serial.println(" dBm");
   
       // print SNR (Signal-to-Noise Ratio) 
       Serial.print("SNR:\t\t");
-      Serial.print(lora.lastPacketSNR);
+      Serial.print(lora.getSNR());
       Serial.println(" dBm");
 
       // print frequency error

examples/SX127x_Settings/SX127x_Settings.ino

@@ -10,6 +10,8 @@
     - coding rate
     - sync word
     - output power during transmission
+
+    Other modules from SX127x/RFM9x family can also be used.
 */
 
 // include the library
@@ -18,18 +20,8 @@
 // SX1278 module is in slot A on the shield
 SX1278 loraSX1278 = Kite.ModuleA;
 
-// create another instance of LoRa class using SX1272 module and user-specified pinout
+// SX1272 module is in slot B on the shield
-// NSS pin:   6
+SX1272 loraSX1272 = Kite.ModuleB;
-// DIO0 pin:  4
-// DIO1 pin:  5
-SX1272 loraSX1272 = new Module(6, 4, 5);
-
-// create third instance of LoRa class using SX1276 module and user-specified pinout
-// we ran out of Uno digital pins, so here we use analog ones
-// NSS pin:   A0
-// DIO0 pin:  A1
-// DIO1 pin:  A2
-SX1276 loraSX1276 = new Module(A0, A1, A2);
 
 void setup() {
   Serial.begin(9600);
@@ -54,28 +46,7 @@ void setup() {
     while (true);
   }
 
-  // initialize the second LoRa instance with non-default settings
+  // initialize the second LoRa instance with
-  // this LoRa link will have maximum range, but very low data rate
-  Serial.print(F("[SX1276] Initializing ... "));
-  // carrier frequency:           434.0 MHz
-  // bandwidth:                   7.8 kHz
-  // spreading factor:            12
-  // coding rate:                 8
-  // sync word:                   0x13
-  // output power:                17 dBm
-  // current limit:               100 mA
-  // preamble length:             8 symbols
-  // amplifier gain:              0 (automatic gain control)
-  state = loraSX1276.begin(434.0, 7.8, 12, 8, 0x13);
-  if (state == ERR_NONE) {
-    Serial.println(F("success!"));
-  } else {
-    Serial.print(F("failed, code "));
-    Serial.println(state);
-    while (true);
-  }
-
-  // initialize the third LoRa instance with
   // non-default settings
   // this LoRa link will have high data rate, 
   // but lower range

examples/SX127x_Transmit/SX127x_Transmit.ino

@@ -7,12 +7,7 @@
     - null-terminated char array (C-string)
     - arbitrary binary data (byte array)
 
-   Other modules from SX127x family can also be used.
+   Other modules from SX127x/RFM9x family can also be used.
-   SX1272 lora = Kite.ModuleA;
-   SX1273 lora = Kite.ModuleA;
-   SX1276 lora = Kite.ModuleA;
-   SX1277 lora = Kite.ModuleA;
-   SX1279 lora = Kite.ModuleA;
 */
 
 // include the library
@@ -64,7 +59,7 @@ void loop() {
 
     // print measured data rate
     Serial.print("Datarate:\t");
-    Serial.print(lora.dataRate);
+    Serial.print(lora.getDataRate());
     Serial.println(" bps");
 
   } else if (state == ERR_PACKET_TOO_LONG) {

examples/SX127x_TransmitInterrupt/SX127x_TransmitInterrupt.ino

@@ -8,12 +8,7 @@
     - null-terminated char array (C-string)
     - arbitrary binary data (byte array)
 
-   Other modules from SX127x family can also be used.
+   Other modules from SX127x/RFM9x family can also be used.
-   SX1272 lora = Kite.ModuleA;
-   SX1273 lora = Kite.ModuleA;
-   SX1276 lora = Kite.ModuleA;
-   SX1277 lora = Kite.ModuleA;
-   SX1279 lora = Kite.ModuleA;
 */
 
 // include the library
@@ -98,6 +93,10 @@ void loop() {
                         0x78, 0xAB, 0xCD, 0xEF};
       int state = lora.transmit(byteArr, 8);
     */
+
+    // NOTE: when using interrupt-driven transmit method,
+    //       it is not possible to automatically measure
+    //       transmission data rate using getDataRate()
     
     if (state != ERR_NONE) {
       Serial.print(F("failed, code "));

keywords.txt

@@ -14,6 +14,10 @@ ESP8266	KEYWORD1
 HC05	KEYWORD1
 JDY08	KEYWORD1
 RF69	KEYWORD1
+RFM95	KEYWORD1
+RFM96	KEYWORD1
+RFM97	KEYWORD1
+RFM98	KEYWORD1
 SX1231	KEYWORD1
 SX1272	KEYWORD1
 SX1273	KEYWORD1
@@ -37,34 +41,43 @@ ModuleA	KEYWORD2
 ModuleB	KEYWORD2
 Module	KEYWORD2
 
-# SX1272/73/76/77/78/79 + RF69
+# SX127x/RFM9x + RF69
-dataRate	KEYWORD2
-lastPacketRSSI	KEYWORD2
 begin	KEYWORD2
+beginFSK	KEYWORD2
 transmit	KEYWORD2
 receive	KEYWORD2
+scanChannel	KEYWORD2
 sleep	KEYWORD2
 standby	KEYWORD2
+transmitDirect	KEYWORD2
+receiveDirect	KEYWORD2
+packetMode	KEYWORD2
+setDio0Action	KEYWORD2
+setDio1Action	KEYWORD2
+startTransmit	KEYWORD2
+startReceive	KEYWORD2
+readData	KEYWORD2
 setBandwidth	KEYWORD2
 setSpreadingFactor	KEYWORD2
 setCodingRate	KEYWORD2
 setFrequency	KEYWORD2
 setSyncWord	KEYWORD2
 setOutputPower	KEYWORD2
-listen	KEYWORD2
+setCurrentLimit	KEYWORD2
-onReceive	KEYWORD2
+setPreambleLength	KEYWORD2
-readData	KEYWORD2
+setGain	KEYWORD2
-transmitDirect	KEYWORD2
+getFrequencyError	KEYWORD2
-receiveDirect	KEYWORD2
+getRSSI	KEYWORD2
-packetMode	KEYWORD2
+getSNR	KEYWORD2
-
+getDataRate	KEYWORD2
-# RF69-specific
 setBitRate	KEYWORD2
 setRxBandwidth	KEYWORD2
 setFrequencyDeviation	KEYWORD2
 setNodeAddress	KEYWORD2
 setBroadcastAddress	KEYWORD2
 disableAddressFiltering	KEYWORD2
+
+# RF69-specific
 setAESKey	KEYWORD2
 enableAES	KEYWORD2
 disableAES	KEYWORD2

src/KiteLib.h

@@ -8,6 +8,10 @@
 #include "modules/HC05.h"
 #include "modules/JDY08.h"
 #include "modules/RF69.h"
+#include "modules/RFM95.h"
+#include "modules/RFM96.h"
+#include "modules/RFM97.h"
+#include "modules/RFM98.h"
 #include "modules/SX1231.h"
 #include "modules/SX1272.h"
 #include "modules/SX1273.h"

src/Module.cpp

@@ -107,7 +107,7 @@ int16_t Module::SPIgetRegValue(uint8_t reg, uint8_t msb, uint8_t lsb) {
   return(maskedValue);
 }
 
-int16_t Module::SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb, uint8_t lsb) {
+int16_t Module::SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb, uint8_t lsb, uint8_t checkInterval) {
   if((msb > 7) || (lsb > 7) || (lsb > msb)) {
     return(ERR_INVALID_BIT_RANGE);
   }
@@ -117,36 +117,39 @@ int16_t Module::SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb, uint8_t
   uint8_t newValue = (currentValue & ~mask) | (value & mask);
   SPIwriteRegister(reg, newValue);
   
-  // some registers need a bit of time to process the change
+  // check register value each millisecond until check interval is reached
-  // e.g. SX127X_REG_OP_MODE
+  // some registers need a bit of time to process the change (e.g. SX127X_REG_OP_MODE)
-  delay(20);
+  uint32_t start = micros();
-  
+  uint8_t readValue = 0;
-  // check if the write was successful
+  while(micros() - start < (checkInterval * 1000)) {
-  uint8_t readValue = SPIreadRegister(reg);
+    readValue = SPIreadRegister(reg);
-  if(readValue != newValue) {
+    if(readValue == newValue) {
-    DEBUG_PRINTLN();
+      // check passed, we can stop the loop
-    DEBUG_PRINT_STR("address:\t0x");
+      return(ERR_NONE);
-    DEBUG_PRINTLN_HEX(reg);
+    }
-    DEBUG_PRINT_STR("bits:\t\t");
-    DEBUG_PRINT(msb);
-    DEBUG_PRINT(' ');
-    DEBUG_PRINTLN(lsb);
-    DEBUG_PRINT_STR("value:\t\t0b");
-    DEBUG_PRINTLN_BIN(value);
-    DEBUG_PRINT_STR("current:\t0b");
-    DEBUG_PRINTLN_BIN(currentValue);
-    DEBUG_PRINT_STR("mask:\t\t0b");
-    DEBUG_PRINTLN_BIN(mask);
-    DEBUG_PRINT_STR("new:\t\t0b");
-    DEBUG_PRINTLN_BIN(newValue);
-    DEBUG_PRINT_STR("read:\t\t0b");
-    DEBUG_PRINTLN_BIN(readValue);
-    DEBUG_PRINTLN();
-    
-    return(ERR_SPI_WRITE_FAILED);
   }
   
-  return(ERR_NONE);
+  // check failed, print debug info
+  DEBUG_PRINTLN();
+  DEBUG_PRINT_STR("address:\t0x");
+  DEBUG_PRINTLN_HEX(reg);
+  DEBUG_PRINT_STR("bits:\t\t");
+  DEBUG_PRINT(msb);
+  DEBUG_PRINT(' ');
+  DEBUG_PRINTLN(lsb);
+  DEBUG_PRINT_STR("value:\t\t0b");
+  DEBUG_PRINTLN_BIN(value);
+  DEBUG_PRINT_STR("current:\t0b");
+  DEBUG_PRINTLN_BIN(currentValue);
+  DEBUG_PRINT_STR("mask:\t\t0b");
+  DEBUG_PRINTLN_BIN(mask);
+  DEBUG_PRINT_STR("new:\t\t0b");
+  DEBUG_PRINTLN_BIN(newValue);
+  DEBUG_PRINT_STR("read:\t\t0b");
+  DEBUG_PRINTLN_BIN(readValue);
+  DEBUG_PRINTLN();
+  
+  return(ERR_SPI_WRITE_FAILED);
 }
 
 void Module::SPIreadRegisterBurst(uint8_t reg, uint8_t numBytes, uint8_t* inBytes) {

src/Module.h

@@ -28,7 +28,7 @@ class Module {
     bool ATsendData(uint8_t* data, uint32_t len);
     
     int16_t SPIgetRegValue(uint8_t reg, uint8_t msb = 7, uint8_t lsb = 0);
-    int16_t SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb = 7, uint8_t lsb = 0);
+    int16_t SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb = 7, uint8_t lsb = 0, uint8_t checkInterval = 2);
     
     void SPIreadRegisterBurst(uint8_t reg, uint8_t numBytes, uint8_t* inBytes);
     uint8_t SPIreadRegister(uint8_t reg);

src/TypeDef.h

@@ -60,7 +60,7 @@
 #define ERR_NONE                               0
 #define ERR_UNKNOWN                            -1
 
-// SX1278/SX1272/RF69 status codes
+// SX127x/RFM9x/RF69 status codes
 #define ERR_CHIP_NOT_FOUND                    -2
 #define ERR_EEPROM_NOT_INITIALIZED            -3
 #define ERR_PACKET_TOO_LONG                   -4

src/modules/RFM95.cpp

@@ -0,0 +1,62 @@
+#include "RFM95.h"
+
+RFM95::RFM95(Module* mod) : SX1278(mod) {
+
+}
+
+int16_t RFM95::begin(float freq, float bw, uint8_t sf, uint8_t cr, uint8_t syncWord, int8_t power, uint8_t currentLimit, uint16_t preambleLength, uint8_t gain) {
+  // execute common part
+  int16_t state = SX127x::begin(RFM95_CHIP_VERSION, syncWord, currentLimit, preambleLength);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  // configure settings not accessible by API
+  state = config();
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  // configure publicly accessible settings
+  state = setFrequency(freq);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setBandwidth(bw);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setSpreadingFactor(sf);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setCodingRate(cr);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setOutputPower(power);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setGain(gain);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  return(state);
+}
+
+int16_t RFM95::setFrequency(float freq) {
+  // check frequency range
+  if((freq < 868.0) || (freq > 915.0)) {
+    return(ERR_INVALID_FREQUENCY);
+  }
+  
+  // set frequency
+  return(SX127x::setFrequencyRaw(freq));
+}

src/modules/RFM95.h

@@ -0,0 +1,27 @@
+#ifndef _KITELIB_RFM95_H
+#define _KITELIB_RFM95_H
+
+#include "TypeDef.h"
+#include "Module.h"
+#include "SX127x.h"
+#include "SX1278.h"
+
+// SX127X_REG_VERSION
+#define RFM95_CHIP_VERSION                            0x11
+
+class RFM95: public SX1278 {
+  public:
+    // constructor
+    RFM95(Module* mod);
+    
+    // basic methods
+    int16_t begin(float freq = 915.0, float bw = 125.0, uint8_t sf = 9, uint8_t cr = 7, uint8_t syncWord = SX127X_SYNC_WORD, int8_t power = 17, uint8_t currentLimit = 100, uint16_t preambleLength = 8, uint8_t gain = 0);
+    
+    // configuration methods
+    int16_t setFrequency(float freq);
+    
+  private:
+  
+};
+
+#endif

src/modules/RFM96.cpp

@@ -0,0 +1,62 @@
+#include "RFM96.h"
+
+RFM96::RFM96(Module* mod) : SX1278(mod) {
+
+}
+
+int16_t RFM96::begin(float freq, float bw, uint8_t sf, uint8_t cr, uint8_t syncWord, int8_t power, uint8_t currentLimit, uint16_t preambleLength, uint8_t gain) {
+  // execute common part
+  int16_t state = SX127x::begin(RFM9X_CHIP_VERSION, syncWord, currentLimit, preambleLength);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  // configure settings not accessible by API
+  state = config();
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  // configure publicly accessible settings
+  state = setFrequency(freq);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setBandwidth(bw);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setSpreadingFactor(sf);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setCodingRate(cr);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setOutputPower(power);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  state = setGain(gain);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+  
+  return(state);
+}
+
+int16_t RFM96::setFrequency(float freq) {
+  // check frequency range
+  if((freq < 433.0) || (freq > 470.0)) {
+    return(ERR_INVALID_FREQUENCY);
+  }
+  
+  // set frequency
+  return(SX127x::setFrequencyRaw(freq));
+}

src/modules/RFM96.h

@@ -0,0 +1,29 @@
+#ifndef _KITELIB_RFM96_H
+#define _KITELIB_RFM96_H
+
+#include "TypeDef.h"
+#include "Module.h"
+#include "SX127x.h"
+#include "SX1278.h"
+
+// SX127X_REG_VERSION
+#define RFM9X_CHIP_VERSION                            0x12  // according to datasheet, this should be 0x11, but all modules seem to have 0x12
+
+class RFM96: public SX1278 {
+  public:
+    // constructor
+    RFM96(Module* mod);
+    
+    // basic methods
+    int16_t begin(float freq = 434.0, float bw = 125.0, uint8_t sf = 9, uint8_t cr = 7, uint8_t syncWord = SX127X_SYNC_WORD, int8_t power = 17, uint8_t currentLimit = 100, uint16_t preambleLength = 8, uint8_t gain = 0);
+    
+    // configuration methods
+    int16_t setFrequency(float freq);
+    
+  private:
+  
+};
+
+using RFM98 = RFM96;
+
+#endif

src/modules/RFM97.cpp

@@ -0,0 +1,39 @@
+#include "RFM97.h"
+
+RFM97::RFM97(Module* mod) : RFM95(mod) {
+
+};
+
+int16_t RFM97::setSpreadingFactor(uint8_t sf) {
+  // check active modem
+  if(getActiveModem() != SX127X_LORA) {
+    return(ERR_WRONG_MODEM);
+  }
+
+  uint8_t newSpreadingFactor;
+  
+  // check allowed spreading factor values
+  switch(sf) {
+    case 6:
+      newSpreadingFactor = SX127X_SF_6;
+      break;
+    case 7:
+      newSpreadingFactor = SX127X_SF_7;
+      break;
+    case 8:
+      newSpreadingFactor = SX127X_SF_8;
+      break;
+    case 9:
+      newSpreadingFactor = SX127X_SF_9;
+      break;
+    default:
+      return(ERR_INVALID_SPREADING_FACTOR);
+  }
+  
+  // set spreading factor and if successful, save the new setting
+  int16_t state = SX1278::setSpreadingFactorRaw(newSpreadingFactor);
+  if(state == ERR_NONE) {
+    SX127x::_sf = sf;
+  }
+  return(state);
+}

src/modules/RFM97.h

@@ -0,0 +1,21 @@
+#ifndef _KITELIB_RFM97_H
+#define _KITELIB_RFM97_H
+
+#include "TypeDef.h"
+#include "Module.h"
+#include "SX127x.h"
+#include "SX1278.h"
+#include "RFM95.h"
+
+class RFM97: public RFM95 {
+  public:
+    // contructor
+    RFM97(Module* mod);
+    
+    // configuration methods
+    int16_t setSpreadingFactor(uint8_t sf);
+  
+  private:
+};
+
+#endif

src/modules/SX1272.cpp

@@ -91,8 +91,12 @@ int16_t SX1272::setFrequency(float freq) {
     return(ERR_INVALID_FREQUENCY);
   }
   
-  // set frequency
+  // set frequency and if successful, save the new setting
-  return(SX127x::setFrequencyRaw(freq));
+  int16_t state = SX127x::setFrequencyRaw(freq);
+  if(state == ERR_NONE) {
+    SX127x::_freq = freq;
+  }
+  return(state);
 }
 
 int16_t SX1272::setBandwidth(float bw) {
@@ -253,6 +257,24 @@ int16_t SX1272::setGain(uint8_t gain) {
   return(state);
 }
 
+int8_t SX1272::getRSSI() {
+  // check active modem
+  if(getActiveModem() != SX127X_LORA) {
+    return(0);
+  }
+  
+  int8_t lastPacketRSSI = -139 + _mod->SPIgetRegValue(SX127X_REG_PKT_RSSI_VALUE);
+  
+  // spread-spectrum modulation signal can be received below noise floor
+  // check last packet SNR and if it's less than 0, add it to reported RSSI to get the correct value
+  float lastPacketSNR = SX127x::getSNR();
+  if(lastPacketSNR < 0.0) {
+    lastPacketRSSI += lastPacketSNR;
+  }
+  
+  return(lastPacketRSSI);
+}
+
 int16_t SX1272::setBandwidthRaw(uint8_t newBandwidth) {
   // set mode to standby
   int16_t state = SX127x::standby();
@@ -300,7 +322,7 @@ int16_t SX1272::config() {
   // calculate symbol length and set low datarate optimization, if needed
   uint16_t base = 1;
   float symbolLength = (float)(base << _sf) / (float)_bw;
-  if(symbolLength >= 0.016) {
+  if(symbolLength >= 16.0) {
     state = _mod->SPIsetRegValue(SX127X_REG_MODEM_CONFIG_1, SX1272_LOW_DATA_RATE_OPT_ON, 0, 0);
   } else {
     state = _mod->SPIsetRegValue(SX127X_REG_MODEM_CONFIG_1, SX1272_LOW_DATA_RATE_OPT_OFF, 0, 0);

src/modules/SX1272.h

@@ -99,6 +99,7 @@ class SX1272: public SX127x {
     int16_t setCodingRate(uint8_t cr);
     int16_t setOutputPower(int8_t power);
     int16_t setGain(uint8_t gain);
+    int8_t getRSSI();
   
   protected:
     int16_t setBandwidthRaw(uint8_t newBandwidth);

src/modules/SX1278.cpp

@@ -147,8 +147,12 @@ int16_t SX1278::setFrequency(float freq) {
     }
   }
   
-  // set frequency
+  // set frequency and if successful, save the new setting
-  return(SX127x::setFrequencyRaw(freq));
+  int16_t state = SX127x::setFrequencyRaw(freq);
+  if(state == ERR_NONE) {
+    SX127x::_freq = freq;
+  }
+  return(state);
 }
 
 int16_t SX1278::setBandwidth(float bw) {
@@ -323,6 +327,31 @@ int16_t SX1278::setGain(uint8_t gain) {
   return(state);
 }
 
+int8_t SX1278::getRSSI() {
+  // check active modem
+  if(getActiveModem() != SX127X_LORA) {
+    return(0);
+  }
+
+  int8_t lastPacketRSSI;
+  
+  // RSSI calculation uses different constant for low-frequency and high-frequency ports
+  if(_freq < 868.0) {
+    lastPacketRSSI = -164 + _mod->SPIgetRegValue(SX127X_REG_PKT_RSSI_VALUE);
+  } else {
+    lastPacketRSSI = -157 + _mod->SPIgetRegValue(SX127X_REG_PKT_RSSI_VALUE);
+  }
+  
+  // spread-spectrum modulation signal can be received below noise floor
+  // check last packet SNR and if it's less than 0, add it to reported RSSI to get the correct value
+  float lastPacketSNR = SX127x::getSNR();
+  if(lastPacketSNR < 0.0) {
+    lastPacketRSSI += lastPacketSNR;
+  }
+  
+  return(lastPacketRSSI);
+}
+
 int16_t SX1278::setBandwidthRaw(uint8_t newBandwidth) {
   // set mode to standby
   int16_t state = SX127x::standby();
@@ -370,7 +399,7 @@ int16_t SX1278::config() {
   // calculate symbol length and set low datarate optimization, if needed
   uint16_t base = 1;
   float symbolLength = (float)(base << _sf) / (float)_bw;
-  if(symbolLength >= 0.016) {
+  if(symbolLength >= 16.0) {
     state = _mod->SPIsetRegValue(SX1278_REG_MODEM_CONFIG_3, SX1278_LOW_DATA_RATE_OPT_ON, 0, 0);
   } else {
     state = _mod->SPIsetRegValue(SX1278_REG_MODEM_CONFIG_3, SX1278_LOW_DATA_RATE_OPT_OFF, 0, 0);

src/modules/SX1278.h

@@ -108,6 +108,7 @@ class SX1278: public SX127x {
     int16_t setCodingRate(uint8_t cr);
     int16_t setOutputPower(int8_t power);
     int16_t setGain(uint8_t gain);
+    int8_t getRSSI();
   
   protected:
     int16_t setBandwidthRaw(uint8_t newBandwidth);
@@ -118,7 +119,7 @@ class SX1278: public SX127x {
     int16_t configFSK();
     
   private:
-    
+  
 };
 
 #endif

src/modules/SX127x.cpp

@@ -42,6 +42,9 @@ int16_t SX127x::begin(uint8_t chipVersion, uint8_t syncWord, uint8_t currentLimi
   // set preamble length
   state = SX127x::setPreambleLength(preambleLength);
   
+  // initalize internal variables
+  _dataRate = 0.0;
+  
   return(state);
 }
 
@@ -128,14 +131,14 @@ int16_t SX127x::transmit(uint8_t* data, size_t len, uint8_t addr) {
     uint16_t base = 1;
     float symbolLength = (float)(base << _sf) / (float)_bw;
     float de = 0;
-    if(symbolLength >= 0.016) {
+    if(symbolLength >= 16.0) {
       de = 1;
     }
     float ih = (float)_mod->SPIgetRegValue(SX127X_REG_MODEM_CONFIG_1, 0, 0);
     float crc = (float)(_mod->SPIgetRegValue(SX127X_REG_MODEM_CONFIG_2, 2, 2) >> 2);
     float n_pre = (float)_mod->SPIgetRegValue(SX127X_REG_PREAMBLE_LSB);
     float n_pay = 8.0 + max(ceil((8.0 * (float)len - 4.0 * (float)_sf + 28.0 + 16.0 * crc - 20.0 * ih)/(4.0 * (float)_sf - 8.0 * de)) * (float)_cr, 0.0);
-    uint32_t timeout = ceil(symbolLength * (n_pre + n_pay + 4.25) * 1000.0);
+    uint32_t timeout = ceil(symbolLength * (n_pre + n_pay + 4.25) * 1.5);
     
     // set DIO mapping
     _mod->SPIsetRegValue(SX127X_REG_DIO_MAPPING_1, SX127X_DIO0_TX_DONE, 7, 6);
@@ -170,7 +173,7 @@ int16_t SX127x::transmit(uint8_t* data, size_t len, uint8_t addr) {
     uint32_t elapsed = millis() - start;
     
     // update data rate
-    dataRate = (len*8.0)/((float)elapsed/1000.0);
+    _dataRate = (len*8.0)/((float)elapsed/1000.0);
     
     // clear interrupt flags
     clearIRQFlags();
@@ -295,11 +298,6 @@ int16_t SX127x::receive(uint8_t* data, size_t len) {
       data[length] = 0;
     }
     
-    // update RSSI and SNR
-    lastPacketRSSI = -157 + _mod->SPIgetRegValue(SX127X_REG_PKT_RSSI_VALUE);
-    int8_t rawSNR = (int8_t)_mod->SPIgetRegValue(SX127X_REG_PKT_SNR_VALUE);
-    lastPacketSNR = rawSNR / 4.0;
-    
     // clear interrupt flags
     clearIRQFlags();
     
@@ -634,11 +632,6 @@ int16_t SX127x::readData(uint8_t* data, size_t len) {
       data[length] = 0;
     }
     
-    // update RSSI and SNR
-    lastPacketRSSI = -157 + _mod->SPIgetRegValue(SX127X_REG_PKT_RSSI_VALUE);
-    int8_t rawSNR = (int8_t)_mod->SPIgetRegValue(SX127X_REG_PKT_SNR_VALUE);
-    lastPacketSNR = rawSNR / 4.0;
-    
     // clear interrupt flags
     clearIRQFlags();
     
@@ -787,6 +780,26 @@ float SX127x::getFrequencyError(bool autoCorrect) {
   return(ERR_UNKNOWN);
 }
 
+float SX127x::getSNR() {
+  // check active modem
+  if(getActiveModem() != SX127X_LORA) {
+    return(0);
+  }
+  
+  // get SNR value
+  int8_t rawSNR = (int8_t)_mod->SPIgetRegValue(SX127X_REG_PKT_SNR_VALUE);
+  return(rawSNR / 4.0);
+}
+
+float SX127x::getDataRate() {
+  // check active modem
+  if(getActiveModem() != SX127X_LORA) {
+    return(0);
+  }
+
+  return(_dataRate);
+}
+
 int16_t SX127x::setBitRate(float br) {
   // check active modem
   if(getActiveModem() != SX127X_FSK_OOK) {
@@ -832,7 +845,7 @@ int16_t SX127x::setFrequencyDeviation(float freqDev) {
     return(state);
   }
   
-  // set frequency deviation from carrier frequency
+  // set allowed frequency deviation
   uint32_t base = 1;
   uint32_t FDEV = (freqDev * (base << 19)) / 32000;
   state = _mod->SPIsetRegValue(SX127X_REG_FDEV_MSB, (FDEV & 0xFF00) >> 8, 5, 0);
@@ -1043,7 +1056,7 @@ int16_t SX127x::config() {
 
 int16_t SX127x::configFSK() {
   // set FSK modulation
-  int16_t state = _mod->SPIsetRegValue(SX127X_REG_OP_MODE, SX127X_MODULATION_FSK, 6, 5);
+  int16_t state = _mod->SPIsetRegValue(SX127X_REG_OP_MODE, SX127X_MODULATION_FSK, 6, 5, 5);
   if(state != ERR_NONE) {
     return(state);
   }
@@ -1119,7 +1132,7 @@ bool SX127x::findChip(uint8_t ver) {
 }
 
 int16_t SX127x::setMode(uint8_t mode) {
-  return(_mod->SPIsetRegValue(SX127X_REG_OP_MODE, mode, 2, 0));
+  return(_mod->SPIsetRegValue(SX127X_REG_OP_MODE, mode, 2, 0, 5));
 }
 
 int16_t SX127x::getActiveModem() {
@@ -1131,7 +1144,7 @@ int16_t SX127x::setActiveModem(uint8_t modem) {
   int16_t state = setMode(SX127X_SLEEP);
   
   // set LoRa mode
-  state |= _mod->SPIsetRegValue(SX127X_REG_OP_MODE, modem, 7, 7);
+  state |= _mod->SPIsetRegValue(SX127X_REG_OP_MODE, modem, 7, 7, 5);
   
   // set mode to STANDBY
   state |= setMode(SX127X_STANDBY);

src/modules/SX127x.h

@@ -522,11 +522,6 @@ class SX127x: public PhysicalLayer {
     // constructor
     SX127x(Module* mod);
     
-    // public member variables
-    float dataRate;
-    int8_t lastPacketRSSI;
-    float lastPacketSNR;
-    
     // basic methods
     int16_t begin(uint8_t chipVersion, uint8_t syncWord, uint8_t currentLimit, uint16_t preambleLength);
     int16_t beginFSK(uint8_t chipVersion, float br, float freqDev, float rxBw, uint8_t currentLimit);
@@ -557,6 +552,8 @@ class SX127x: public PhysicalLayer {
     int16_t setCurrentLimit(uint8_t currentLimit);
     int16_t setPreambleLength(uint16_t preambleLength);
     float getFrequencyError(bool autoCorrect = false);
+    float getSNR();
+    float getDataRate();
     int16_t setBitRate(float br);
     int16_t setFrequencyDeviation(float freqDev);
     int16_t setRxBandwidth(float rxBw);
@@ -572,6 +569,7 @@ class SX127x: public PhysicalLayer {
   protected:
     Module* _mod;
     
+    float _freq;
     float _bw;
     uint8_t _sf;
     uint8_t _cr;
@@ -587,6 +585,8 @@ class SX127x: public PhysicalLayer {
     int16_t directMode();
   
   private:
+    float _dataRate;
+  
     bool findChip(uint8_t ver);
     int16_t setMode(uint8_t mode);
     int16_t setActiveModem(uint8_t modem);