More interoperability cases

config.h

@@ -93,7 +93,8 @@
 #define CFG_IS_TO_RF          false   // forward packets from internet to radio based on CFG_APRS_FILTER
 #define CFG_BEACON            false   // enable perdiodic beacon from CFG_APRS_RAW_BKN
 #define CFG_TEXT_PACKETS      false   // enable aprs TNC2 text packets instead of binary for interoperability with other projects (disables KISS + AX.25!)
-#define CFG_TEXT_PACKETS_PREFIX false // // true - enable aprs-lora 3 byte prefix '<', 0xff, 0x01
+#define CFG_TEXT_PACKETS_3    false   // true - enable aprs-lora 3 byte prefix '<', 0xff, 0x01
+#define CFG_TEXT_PACKETS_4    false   // true - enable oe3cjb 4 byte prefix
 
 // Frequency correction for narrow band bandwidths
 #define CFG_FREQ_CORR         false   // true - correct own frequency based on received packet

esp32_loraprs.ino

@@ -83,7 +83,8 @@ void initializeConfig(LoraPrs::Config &cfg) {
   cfg.EnableRepeater = CFG_DIGIREPEAT; // digirepeat incoming packets
   cfg.EnableBeacon = CFG_BEACON;  // enable periodic AprsRawBeacon beacon to rf and aprsis if rf to aprsis is enabled
   cfg.EnableTextPackets = CFG_TEXT_PACKETS; // enables TNC2 text packets and disables KISS+AX25 binary frames for interoperability
-  cfg.EnableTextPacketsPrefix = CFG_TEXT_PACKETS_PREFIX; // enable aprs-lora 3 byte prefix '<', 0xff, 0x01
+  cfg.EnableTextPackets3 = CFG_TEXT_PACKETS_3; // enable aprs-lora 3 byte prefix '<', 0xff, 0x01
+  cfg.EnableTextPackets4 = CFG_TEXT_PACKETS_4; // enable 4 byte prefix
 
   // kiss
   cfg.KissEnableExtensions = CFG_KISS_EXTENSIONS; // radio control and signal reports

kiss_processor.cpp

@@ -4,7 +4,8 @@ namespace Kiss {
 
 Processor::Processor()
   : disableKiss_(false)
-  , usePrefix_(false)
+  , usePrefix3_(false)
+  , usePrefix4_(false)
   , isRawIdle_(true)
   , state_(State::GetStart)
 {
@@ -66,11 +67,17 @@ void Processor::queueSerialToRig(Cmd cmd, const byte *packet, int packetLength)
   bool result = 1;
   if (disableKiss_) {
     // inject proprietary identifier
-    if (usePrefix_) {
+    if (usePrefix3_) {
       result &= serialToRigQueue_.unshift('<');
       result &= serialToRigQueue_.unshift(0xff);
       result &= serialToRigQueue_.unshift(0x01);
     }
+    if (usePrefix4_) {
+      result &= serialToRigQueue_.unshift(' ');
+      result &= serialToRigQueue_.unshift(' ');
+      result &= serialToRigQueue_.unshift(' ');
+      result &= serialToRigQueue_.unshift(' ');
+    }
     // TNC2, send as is, receiveByteRaw will deal with it
     for (int i = 0; i < packetLength; i++) {
       byte rxByte = packet[i];
@@ -121,15 +128,23 @@ bool Processor::processRigToSerial()
     int readCnt = rxPacketSize;
     for (int i = 0, j = 0; i < readCnt; i++) {
       byte rxByte = rigToSerialQueue_.pop();
-      if (disableKiss_ && usePrefix_) {
+      if (disableKiss_) {   
         // filter out properietary identifier
-        if ((i == 0 && rxByte == '<') ||
-            (i == 1 && rxByte == 0xff) ||
-            (i == 2 && rxByte == 0x01)) 
-           {
+        if (usePrefix3_) {
+          if ((i == 0 && rxByte == '<') ||
+              (i == 1 && rxByte == 0xff) ||
+              (i == 2 && rxByte == 0x01)) 
+          {
             rxPacketSize--;
             continue;
-           }
+          }
+        // filter out first 4 bytes
+        } else if (usePrefix4_) {
+          if (i >= 0 && i <= 3) {
+            rxPacketSize--;
+            continue;
+          }
+        }
       }
       buf[j++] = rxByte;
     }

kiss_processor.h

@@ -85,7 +85,8 @@ private:
 
 protected:
   bool disableKiss_;
-  bool usePrefix_;
+  bool usePrefix3_;
+  bool usePrefix4_;
 
 private:
   bool isRawIdle_;

loraprs_config.h

@@ -68,7 +68,8 @@ struct Config
   bool EnableRepeater;                  // true - digirepeat incoming packets based on WIDEn-n paths
   bool EnableBeacon;                    // true - send AprsRawBeacon to RF and APRS-IS if EnableRfToIs is true
   bool EnableTextPackets;               // true - use TNC2 text plain messages insead of AX25 binary frames for interoperability with other projects
-  bool EnableTextPacketsPrefix;         // true - enable aprs-lora 3 byte prefix '<', 0xff, 0x01
+  bool EnableTextPackets3;              // true - enable aprs-lora 3 byte prefix '<', 0xff, 0x01
+  bool EnableTextPackets4;              // true - enable oe3cjb 4 byte prefix
 
   // external ptt tx control
   bool PttEnable;                       // true - enable external ptt control

loraprs_service.cpp

@@ -27,7 +27,8 @@ void Service::setup(const Config &conf)
   config_ = conf;  
   beaconLastTimestampMs_ = 0;
   disableKiss_ = conf.EnableTextPackets;
-  usePrefix_ = conf.EnableTextPacketsPrefix;
+  usePrefix3_ = conf.EnableTextPackets3;
+  usePrefix4_ = conf.EnableTextPackets4;
 
   LOG_SET_OPTION(false, false, true);  // disable file, line, enable func