LoRaWAN-Signal-Mapping/iot/main/storage.cpp

#include <Arduino.h>
#include <SdFat.h>
// #include <ArduinoFiles.h>

#include "settings.h"
#include "gps.h"

// FUTURE: We might be able to trim it down if we disable long filenames with #define USE_LONG_FILE_NAMES 0
SdFat* card = nullptr;

void store_init() {
	card = new SdFat();
	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) {
	// Port the rest of this to SdFat from SD
	
	// Open the file to  write the data to. If it doesn't exist it will be created.
	// Unlike elsewhere, FILE_WRITE opens the file with the cursor starting at the end, so it's basically actually equivalent to FILE_APPEND that we use in other environments. Confusing, I know.
	File handle = card->open(SD_FILENAME, O_APPEND | O_CREAT | O_WRONLY);
	
	char line[33];
	int chars = snprintf(line, 33, "%d\t%06d\t%06d\n",
		id,
		location.lat, location.lng
	);
	handle.write(line, chars);
	
	handle.close(); // Syncs implicitly
}

void store_debug(char* buffer, int size) {
	File handle = card->open(SD_FILENAME_DEBUG, O_APPEND | O_CREAT | O_WRONLY);
	handle.write(buffer, size);
	handle.write('\n');
	handle.close();
}

void store_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;
}