Makefile addition for GRUVIN9X PCB PORTH real-time diagnostics.

$ make ... PORTH_TIMING=YES

See code comments for details. This is used to analyse real-world timing of
mixer interrupt, setupPulses and PPM or DSM=SERIAL or DSM2=PPM data output
streams.

NOTE: Not compatible to SOUND=YES (SOMO14)

src/pulses_avr.cpp

@@ -729,6 +729,11 @@ static void setupPulsesPiccoZ(uint8_t chn)
 void setupPulses()
 {
   uint8_t required_protocol = g_model.protocol;
+
+#ifdef PORTH_TIMING
+    PORTH |= 0x80; // PORTH:7 LOW->HIGH signals start of setupPulses()
+#endif
+
   if (s_pulses_paused)
     required_protocol = PROTO_NONE;
 
@@ -884,6 +889,11 @@ void setupPulses()
       // if PPM16, PPM16 pulses are set up automatically within the interrupts
       break;
   }
+
+#ifdef PORTH_TIMING
+    PORTH &= ~0x80; // PORTH:7 HIGH->LOW signals end of setupPulses()
+#endif
+
 }
 
 #ifndef SIMU