Update CSMA logic to take SlotTime into account

loraprs_service.cpp

@@ -148,7 +148,7 @@ void Service::loop()
     onLoraDataAvailable(packetSize);
   }
   // TX path
-  else if (random(0, 255) < CfgCsmaProbBoundary) {
+  else if (random(0, 255) < CfgCsmaPersistence) {
     if (serialBt_.available()) {
       onBtDataAvailable();
     }
@@ -159,6 +159,9 @@ void Service::loop()
       sendPeriodicBeacon();
     }
   }
+  else {
+    delay(CfgCsmaSlotTimeMs);
+  }
   delay(CfgPollDelayMs);
 }
 

loraprs_service.h

@@ -66,11 +66,11 @@ private:
 
   const String CfgLoraprsVersion = "LoRAPRS 0.1";
 
-  // tune depending on TOA, higher value for higher time on air
+  const int CfgPollDelayMs = 10;
-  const int CfgPollDelayMs = 500;
 
   // tx when lower than this value from random 0..255, use lower value for high traffic
-  const long CfgCsmaProbBoundary = 100;
+  const long CfgCsmaPersistence = 100;
+  const long CfgCsmaSlotTimeMs = 500;
 
   const byte CfgPinSs = 5;
   const byte CfgPinRst = 26;