we now always listen before transmit - even if we have just completed a packet

src/mesh/RadioLibInterface.h

@@ -14,9 +14,10 @@
 class RadioLibInterface : public RadioInterface
 {
     /// Used as our notification from the ISR
-    enum PendingISR { ISR_NONE = 0, ISR_RX, ISR_TX };
+    enum PendingISR { ISR_NONE = 0, ISR_RX, ISR_TX, TRANSMIT_DELAY_COMPLETED };
 
     volatile PendingISR pending = ISR_NONE;
+    volatile bool timerRunning = false;
 
     /** Our ISR code currently needs this to find our active instance
      */
@@ -25,7 +26,7 @@ class RadioLibInterface : public RadioInterface
     /**
      * Raw ISR handler that just calls our polymorphic method
      */
-    static void isrTxLevel0();
+    static void isrTxLevel0(), isrLevel0Common(PendingISR code);
 
     /**
      * Debugging counts
@@ -43,8 +44,8 @@ class RadioLibInterface : public RadioInterface
      */
     uint8_t syncWord = SX126X_SYNC_WORD_PRIVATE;
 
-    float currentLimit = 100;    // FIXME
-    uint16_t preambleLength = 8; // 8 is default, but FIXME use longer to increase the amount of sleep time when receiving
+    float currentLimit = 100;     // FIXME
+    uint16_t preambleLength = 32; // 8 is default, but FIXME use longer to increase the amount of sleep time when receiving
 
     Module module; // The HW interface to the radio
 
@@ -83,12 +84,18 @@ class RadioLibInterface : public RadioInterface
     /** start an immediate transmit */
     void startSend(MeshPacket *txp);
 
-    /** start a queued transmit (if we have one), else start receiving */
-    void startNextWork();
+    /** if we have something waiting to send, start a short random timer so we can come check for collision before actually doing
+     * the transmit 
+     * 
+     * If the timer was already running, we just wait for that one to occur.
+     * */
+    void startTransmitTimer(bool withDelay = true);
 
     void handleTransmitInterrupt();
     void handleReceiveInterrupt();
 
+    static void timerCallback(void *p1, uint32_t p2);
+
   protected:
     /**
      * Convert our modemConfig enum into wf, sf, etc...