Allow specifying some more lora parameters from config.h

config.h

@@ -53,13 +53,15 @@
 #define CFG_LORA_USE_CAD      true        // set to true to utilize carrier detection
 #endif
 
-// lora protocol default parameters
-#define CFG_LORA_FREQ         433.775E6
-#define CFG_LORA_BW           125e3
-#define CFG_LORA_SF           12
-#define CFG_LORA_CR           7
-#define CFG_LORA_PWR          20
-#define CFG_LORA_ENABLE_CRC   true        // set to false for speech data
+// lora protocol default parameters (they need to match between devices!!!)
+#define CFG_LORA_FREQ         433.775e6   // frequency in MHz
+#define CFG_LORA_BW           125e3       // bandwidth (from 7.8 kHz up to 500 kHz)
+#define CFG_LORA_SF           12          // spreading factor (7 - 12)
+#define CFG_LORA_CR           7           // coding rate (5 - 8)
+#define CFG_LORA_CRC          1           // 0 - disabled, 1 - 1 byte, 2 - 2 bytes
+#define CFG_LORA_EXPLICIT     true        // header mode, true - explicit, false - implicit
+#define CFG_LORA_SYNC         0x34        // sync word (0x12 - private, 0x34 - public)
+#define CFG_LORA_PWR          20          // output power in dBm
 
 // wifi client and AP options
 #define CFG_WIFI_ENABLE_AP    false       // run as wifi access point (for CFG_KISS_TCP_IP mode)

esp32_loraprs.ino

@@ -30,14 +30,15 @@ void initializeConfig(LoraPrs::Config &cfg) {
   // client/server mode switch
   cfg.IsClientMode = CFG_IS_CLIENT_MODE;
 
-  // lora parameters
+  // lora parameters, mus match on devices
   cfg.LoraFreq = CFG_LORA_FREQ;
   cfg.LoraBw = CFG_LORA_BW;
   cfg.LoraSf = CFG_LORA_SF;
   cfg.LoraCodingRate = CFG_LORA_CR;
-  cfg.LoraSync = 0x34;
+  cfg.LoraSync = CFG_LORA_SYNC;
+  cfg.LoraCrc = CFG_LORA_CRC; // set to 0 to disable
+  cfg.LoraExplicit = CFG_LORA_EXPLICIT;
   cfg.LoraPower = CFG_LORA_PWR;
-  cfg.LoraEnableCrc = CFG_LORA_ENABLE_CRC; // set to false for speech streaming data
 
   // lora pinouts
   cfg.LoraPinSs = CFG_LORA_PIN_SS;

loraprs_config.h

@@ -17,8 +17,9 @@ struct Config
   int LoraSf;           // lora spreading factor, e.g. 12
   int LoraCodingRate;   // lora coding rate, e.g. 7
   int LoraPower;        // lora power level in dbm, 20
-  int LoraSync;         // lora sync word/packet id, 0x3f
-  bool LoraEnableCrc;   // lora crc check enabled
+  int LoraSync;         // lora sync word/packet id, 0x34
+  int LoraCrc;          // lora crc mode, 0 - disabled, 1 - 1 byte, 2 - 2 bytes
+  bool LoraExplicit;    // lora header mode, true - explicit, false - implicit
 
   // lora hardware pinouts and isr
   byte LoraPinSs;       // lora ss pin

loraprs_service.cpp

@@ -68,7 +68,7 @@ void Service::setup(const Config &conf)
 
   // peripherals, LoRa
   setupLora(config_.LoraFreq, config_.LoraBw, config_.LoraSf, 
-    config_.LoraCodingRate, config_.LoraPower, config_.LoraSync, config_.LoraEnableCrc);
+    config_.LoraCodingRate, config_.LoraPower, config_.LoraSync, config_.LoraCrc, config_.LoraExplicit);
 
 #ifdef USE_RADIOLIB
   if (!config_.LoraUseIsr) {
@@ -193,18 +193,20 @@ bool Service::reconnectAprsis()
   return true;
 }
 
-void Service::setupLora(long loraFreq, long bw, int sf, int cr, int pwr, int sync, bool enableCrc)
+void Service::setupLora(long loraFreq, long bw, int sf, int cr, int pwr, int sync, int crcBytes, bool isExplicit)
 {
+  isImplicitHeaderMode_ = !isExplicit;
+  isImplicitHeaderMode_ = sf == 6;      // must be implicit for SF6
+  
   LOG_INFO("Initializing LoRa");
   LOG_INFO("Frequency:", loraFreq, "Hz");
   LOG_INFO("Bandwidth:", bw, "Hz");
   LOG_INFO("Spreading:", sf);
   LOG_INFO("Coding rate:", cr);
   LOG_INFO("Power:", pwr, "dBm");
-  LOG_INFO("Sync:", "0x" + String(sync, 16));
-  LOG_INFO("CRC:", enableCrc ? "enabled" : "disabled");
-  
-  isImplicitHeaderMode_ = sf == 6;
+  LOG_INFO("Sync:", "0x" + String(sync, HEX));
+  LOG_INFO("CRC:", crcBytes);
+  LOG_INFO("Header:", isImplicitHeaderMode_ ? "implicit" : "explicit");
 
 #ifdef USE_RADIOLIB
   radio_ = std::make_shared<MODULE_NAME>(new Module(config_.LoraPinSs, config_.LoraPinA, config_.LoraPinRst, config_.LoraPinB));
@@ -212,8 +214,7 @@ void Service::setupLora(long loraFreq, long bw, int sf, int cr, int pwr, int syn
   if (state != ERR_NONE) {
     LOG_ERROR("Radio start error:", state);
   }
-  radio_->setCRC(enableCrc);
-  //radio_->forceLDRO(false);
+  radio_->setCRC(crcBytes);
   #ifdef USE_SX126X
     #pragma message("Using SX126X")
     LOG_INFO("Using SX126X module");
@@ -235,6 +236,12 @@ void Service::setupLora(long loraFreq, long bw, int sf, int cr, int pwr, int syn
     }
   #endif
 
+  if (isImplicitHeaderMode_) {
+    radio_->implicitHeader(0xff);
+  } else {
+    radio_->explicitHeader();
+  }
+  
   state = radio_->startReceive();
   if (state != ERR_NONE) {
     LOG_ERROR("Receive start error:", state);
@@ -818,10 +825,10 @@ void Service::onRadioControlCommand(const std::vector<byte> &rawCommand) {
     config_.LoraCodingRate = be16toh(setHardware->cr);
     config_.LoraPower = be16toh(setHardware->pwr);
     config_.LoraSync = be16toh(setHardware->sync);
-    config_.LoraEnableCrc = setHardware->crc;
+    int crcType = setHardware->crc ? config_.LoraCrc : 0;
 
     setupLora(config_.LoraFreq, config_.LoraBw, config_.LoraSf, 
-      config_.LoraCodingRate, config_.LoraPower, config_.LoraSync, config_.LoraEnableCrc);
+      config_.LoraCodingRate, config_.LoraPower, config_.LoraSync, crcType, config_.LoraExplicit);
   } else {
     LOG_ERROR("Radio control command of wrong size");
   }

loraprs_service.h

@@ -41,7 +41,7 @@ private:
   void printConfig();
 
   void setupWifi(const String &wifiName, const String &wifiKey);
-  void setupLora(long loraFreq, long bw, int sf, int cr, int pwr, int sync, bool enableCrc);
+  void setupLora(long loraFreq, long bw, int sf, int cr, int pwr, int sync, int crcBytes, bool isExplicit);
   void setupBt(const String &btName);
 
   void reconnectWifi() const;