Time keep for NRF52 across resets

src/helpers/ArduinoHelpers.cpp

@@ -0,0 +1,6 @@
+#include <stdint.h>
+
+extern "C" {
+    __attribute__((section(".persistent_magic"))) uint32_t persistent_magic;
+    __attribute__((section(".persistent_data"))) uint32_t persistent_time;
+}