Add callback for board-specific actions on radio RX interrupt

In some cases it is useful to let the board driver know when the radio
issues an RX interrupt. This can be used to wake up the board from a
low power state asynchronously for example.

Signed-off-by: Frieder Schrempf <frieder@fris.de>

Author: fschrempf

src/MeshCore.h

@@ -53,6 +53,7 @@ class MainBoard {
   virtual const char* getManufacturerName() const = 0;
   virtual void onBeforeTransmit() { }
   virtual void onAfterTransmit() { }
+  virtual void onRXInterrupt() {}
   virtual void reboot() = 0;
   virtual void powerOff() { /* no op */ }
   virtual void enterSleep(uint32_t secs) {

src/helpers/radiolib/RadioLibWrappers.cpp

@@ -12,6 +12,7 @@
 #define SAMPLING_THRESHOLD  14
 
 static volatile uint8_t state = STATE_IDLE;
+static mesh::MainBoard *board;
 
 // this function is called when a complete packet
 // is transmitted by the module
@@ -22,9 +23,12 @@ static
     void radioISR(void) {
   // we sent a packet, set the flag
   state |= STATE_INT_READY;
+
+  if (state & STATE_RX) board->onRXInterrupt();
 }
 
 void RadioLibWrapper::begin() {
+  board = _board;
   _radio->setPacketReceivedAction(radioISR); // this is also SentComplete interrupt
   state = STATE_IDLE;