G9Xv4 Board: Committing TX_CADDY feature to trunk.

This feature allows use of a transmitter module 'caddy' PCB, which facilitates
automatic DSM2(X) or Fr-Sky transmitter module switching, without having to
swap TX module on the back of the radio. Two antennas are installed on the
radio instead of attempting to switch 2.4GHz RF signals, for reliability. The
TX Caddy circuit schematic and PCB layout can be found in the gruvin9x hardware
project.

I am not really expecting anyone else to implement this feature. But it's there 
for those who might and adding it to trunk prevent me having to manually port 
the feature to new versions, each time I update my field radio.

-- Gruvin

src/Makefile

@@ -157,6 +157,11 @@ PXX = NO
 # Values = NO, SERIAL, PPM
 DSM2 = NO
 
+# DSM/PPM TX caddy PCB (Gruvin)
+# For auto-switching switching between DSM2/X and Fr-Sky transmitter modules
+# Values = YES, NO
+TX_CADDY = NO
+
 #IR protocols (SILV / TRAC09 / PICZ / SWIFT)
 IRPROTOS = NO
 
@@ -662,6 +667,10 @@ ifeq ($(DSM2), PPM)
   CPPDEFS += -DDSM2 -DDSM2_PPM
 endif
 
+ifeq ($(TX_CADDY), YES)
+  CPPDEFS += -DTX_CADDY
+endif
+
 ifeq ($(IRPROTOS), YES)
   CPPDEFS += -DIRPROTOS
 endif

src/pulses_avr.cpp

@@ -736,6 +736,13 @@ void setupPulses()
     PORTH |= 0x80; // PORTH:7 LOW->HIGH signals start of setupPulses()
 #endif
 
+#if defined (PCBGRUVIN9X) && defined(TX_CADDY)
+    if (required_protocol == PROTO_DSM2)
+      PORTH &= ~0x80;
+    else
+      PORTH |= 0x80;
+#endif
+
   if (s_pulses_paused)
     required_protocol = PROTO_NONE;