misc NRF52 fixes

src/rf95/RH_RF95.cpp

@@ -114,6 +114,11 @@ bool RH_RF95::init()
     return enableInterrupt();
 }
 
+// If on a platform without level trigger definitions, just use RISING and suck it up.
+#ifndef ONHIGH
+#define ONHIGH RISING
+#endif
+
 bool RH_RF95::enableInterrupt()
 {
     // Determine the interrupt number that corresponds to the interruptPin

src/rf95/RadioInterface.h

@@ -39,6 +39,16 @@ class RadioInterface
 
     virtual void loop() {} // Idle processing
 
+    /**
+     * Return true if we think the board can go to sleep (i.e. our tx queue is empty, we are not sending or receiving)
+     *
+     * This method must be used before putting the CPU into deep or light sleep.
+     */
+    bool canSleep() { return true; }
+
+    /// Prepare hardware for sleep.  Call this _only_ for deep sleep, not needed for light sleep.
+    virtual bool sleep() { return true; }
+
     /**
      * Send a packet (possibly by enquing in a private fifo).  This routine will
      * later free() the packet to pool.  This routine is not allowed to stall.