#include <SPI.h>
#include <SD.h>
#include "HX711.h"
#include <Arduino.h>

File myFile;
const int LOADCELL_DOUT_PIN = 10;
const int LOADCELL_SCK_PIN = 9;
const int CS = 7;
float strain = 10;
bool SDFailed = true;
HX711 scale;

void WriteFile1(const char* path, unsigned long tiime, float strain1) {
  // open file, append data, close file
  myFile = SD.open(path, FILE_APPEND);
  if (myFile) {
    myFile.print(tiime);
    myFile.print(",");
    myFile.println(strain1, 5);
    myFile.close();
  }
  else {
    Serial.println("error opening file");
    Serial.println(path);
  }
}
void WriteFile2(const char* path, const char* message) {
  // open file, append data, close file
  myFile = SD.open(path, FILE_WRITE);
  if (myFile) {
    Serial.printf("Writing to %s ", path);
    myFile.println(message);
    myFile.close();
    Serial.println("completed.");
  }
  else {
    Serial.println("error opening file ");
    Serial.println(path);
  }
}

void ReadFile(const char* path) {
  // open the file for reading:
  myFile = SD.open(path);
  if (myFile) {
    while (myFile.available()) {
      Serial.write(myFile.read());
    }
    myFile.close();
  } else {
    Serial.println("error opening file");
    Serial.println(path);
  }
}

void setup() {
  Serial.begin(115200);
  delay(500);
  while (!Serial) { ; }
  Serial.println("Initializing SD card...");
  if (!SD.begin(CS)) {
    Serial.println("Initialization Failed!");
    return;
  }
  Serial.println("Initialization Done.");
  SDFailed = false;
  WriteFile2("/test.txt", "Time,Mass");
  ReadFile("/test.txt");
  
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  
  scale.set_scale(420);
  scale.tare();
  Serial.println("END SETUP.");
  delay(250);
  
  //scale.power_down();
}

void loop() {
  // nothing happens after setup
  if (!SDFailed) {
    delay(1.0);
    strain = scale.get_units();
    Serial.println(strain);
    WriteFile1("/test.txt", millis(), strain);
  }
  else {
    delay(500);
    Serial.print("SDCard OK?");
    Serial.println(SDFailed);
  }
  //ReadFile("/test.txt");
}