Preliminary Thinknode M4 Support (#8754)

* Preliminary Thinknode M4 Support

* oops

* Fix RF switch TX configuration

* trunk'd

* GPS fix for M4

* Battery handling and LED for M4

* Trunk

* Drop debug warnings

* Make Red LED notification

* Merge cleanup

* Make white LEDs flash during charge

---------

Co-authored-by: Jonathan Bennett <jbennett@incomsystems.biz>

src/gps/GPS.cpp

@@ -896,14 +896,11 @@ void GPS::writePinEN(bool on)
 void GPS::writePinStandby(bool standby)
 {
 #ifdef PIN_GPS_STANDBY // Specifically the standby pin for L76B, L76K and clones
-
-// Determine the new value for the pin
-// Normally: active HIGH for awake
-#ifdef PIN_GPS_STANDBY_INVERTED
-    bool val = standby;
-#else
-    bool val = !standby;
-#endif
+    bool val;
+    if (standby)
+        val = GPS_STANDBY_ACTIVE;
+    else
+        val = !GPS_STANDBY_ACTIVE;
 
     // Write and log
     pinMode(PIN_GPS_STANDBY, OUTPUT);

src/gps/GPS.h

@@ -16,6 +16,11 @@
 #define GPS_EN_ACTIVE 1
 #endif
 
+// Allow defining the polarity of the STANDBY output.  default is LOW for standby
+#ifndef GPS_STANDBY_ACTIVE
+#define GPS_STANDBY_ACTIVE LOW
+#endif
+
 static constexpr uint32_t GPS_UPDATE_ALWAYS_ON_THRESHOLD_MS = 10 * 1000UL;
 static constexpr uint32_t GPS_FIX_HOLD_MAX_MS = 20000;