the mountain of changes needed to kinda make tx work compiles.

src/rf95/RadioInterface.cpp

@@ -6,7 +6,10 @@
 #include <pb_decode.h>
 #include <pb_encode.h>
 
-RadioInterface::RadioInterface() {}
+RadioInterface::RadioInterface() : txQueue(MAX_TX_QUEUE)
+{
+    assert(sizeof(PacketHeader) == 4); // make sure the compiler did what we expected
+}
 
 ErrorCode SimRadio::send(MeshPacket *p)
 {
@@ -21,3 +24,32 @@ void RadioInterface::deliverToReceiver(MeshPacket *p)
     assert(rxDest->enqueue(p, 0)); // NOWAIT - fixme, if queue is full, delete older messages
 }
 
+/***
+ * given a packet set sendingPacket and decode the protobufs into radiobuf.  Returns # of payload bytes to send
+ */
+size_t RadioInterface::beginSending(MeshPacket *p)
+{
+    assert(!sendingPacket);
+
+    // DEBUG_MSG("sending queued packet on mesh (txGood=%d,rxGood=%d,rxBad=%d)\n", rf95.txGood(), rf95.rxGood(), rf95.rxBad());
+    assert(p->has_payload);
+
+    lastTxStart = millis();
+
+    PacketHeader *h = (PacketHeader *)radiobuf;
+
+    h->from = p->from;
+    h->to = p->to;
+    h->flags = 0;
+    h->id = p->id;
+
+    // if the sender nodenum is zero, that means uninitialized
+    assert(h->from);
+
+    size_t numbytes = pb_encode_to_bytes(radiobuf + sizeof(PacketHeader), sizeof(radiobuf), SubPacket_fields, &p->payload) + sizeof(PacketHeader);
+
+    assert(numbytes <= MAX_RHPACKETLEN);
+
+    sendingPacket = p;
+    return numbytes;
+}