wio_e5_mini: led and rescue cli

variants/wio-e5-mini/NullDisplayDriver.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <helpers/ui/DisplayDriver.h>
+
+class NullDisplayDriver : public DisplayDriver {
+public:
+  NullDisplayDriver() : DisplayDriver(128, 64) { }
+  bool begin() { return false; }   // not present
+
+  bool isOn() override { return false; }
+  void turnOn() override { }
+  void turnOff() override { }
+  void clear() override { }
+  void startFrame(Color bkg = DARK) override { }
+  void setTextSize(int sz) override { }
+  void setColor(Color c) override { }
+  void setCursor(int x, int y) override { }
+  void print(const char* str) override { }
+  void fillRect(int x, int y, int w, int h) override { }
+  void drawRect(int x, int y, int w, int h) override { }
+  void drawXbm(int x, int y, const uint8_t* bits, int w, int h) override { }
+  uint16_t getTextWidth(const char* str) override { return 0; }
+  void endFrame() { }
+};