stub out some functions that still need to be removed or refactored

nano_gui.h

@@ -18,6 +18,11 @@ void displayFillrect(unsigned int x,unsigned int y,unsigned int w,unsigned int h
 void displayChar(int16_t x, int16_t y, unsigned char c, uint16_t color, uint16_t bg);
 void displayText(const char *const text, int x1, int y1, int w, int h, int color, int background, int border, TextJustification_e justification = TextJustification_e::Center);
 
+/* these functions are called universally to update the display */
+void updateDisplay(); //updates just the VFO frequency to show what is in 'frequency' variable
+void redrawVFOs();    //redraws only the changed digits of the vfo
+void drawTx();
+
 #define TEXT_LINE_HEIGHT 18
 #define TEXT_LINE_INDENT 5
 

tmp.cpp

@@ -0,0 +1,12 @@
+#include <Arduino.h>
+#include "pin_definitions.h"
+
+void updateDisplay() {}
+void redrawVFOs(){}
+void drawTx(){}
+int btnDown()
+{
+  //Button has a pullup, so it reads high normally,
+  //and reads low when pressed down
+  return !digitalRead(PIN_ENC_PUSH_BUTTON);
+}