Fix compilation warnings

iot/main/main.ino

@@ -1,7 +1,6 @@
 #include "settings.h"
 #include <Arduino.h>
 #include <TinyGPS++.h>
-#include <SD.h>
 #include <MemoryFree.h>
 
 #include "random.h"
@@ -45,7 +44,7 @@ void setup() {
 	store_debug(gps_data.time, 19);
 	#endif
 	Serial.println(freeMemory(), DEC);
-	store_close();
+	store_end();
 	Serial.println(freeMemory(), DEC);
 	
 	// ------------------------------------------------------------------------

iot/main/storage.cpp

@@ -10,7 +10,10 @@ SdFat* card = nullptr;
 
 void store_init() {
 	card = new SdFat();
-	card->begin(PIN_SPI_CS_SD);
+	if(!card->begin(PIN_SPI_CS_SD)) {
+		Serial.println("Error: MicroSD card init failed");
+		while(true) delay(100);
+	}
 }
 
 void store_reading(uint32_t id, GPSLocation location) {
@@ -38,6 +41,8 @@ void store_debug(char* buffer, int size) {
 }
 
 void store_end() {
-	card.end();
+	// Apparently we'ree fine so long as we don't have any open file handles - there's no end() method on the SdFat class
+	// card->end();
 	delete card;
+	card = nullptr;
 }

iot/main/storage.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <SPI.h>
-#include <SD.h>
+#include <SdFat.h>
 
 #include <TinyGPS++.h>
 
@@ -11,4 +11,4 @@ void store_reading(uint32_t id, GPSLocation location);
 
 void store_debug(char* buffer, int size);
 
-void store_close();
+void store_end();