#include <HX711.h>
#include <SD.h>
#include <SPI.h>
#include <RTClib.h>

// Pin definitions
#define LOADCELL_DOUT_PIN 2
#define LOADCELL_SCK_PIN 3
#define CS_PIN 10

// Initialize objects
HX711 scale;
RTC_DS3231 rtc;
File ispFile;

// Variables
float threshold = 0.1; // Minimum load to trigger logging (kg)
bool isLogging = false;
unsigned long lastMeasurement = 0;
const int measureInterval = 12; // For 80Hz (1000ms/80 = 12.5ms)

void setup() {
  Serial.begin(9600);
  Serial.println(F("Thrust Logger Initializing"));
  Serial.println(F("Scale has been initialized..."));
  Serial.println(F("RTC has been initialized..."));
  Serial.println(F("SD card has been initialized..."));
 
  // Initialize scale
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  scale.set_scale(168.0); // Replace with your calibration value
  scale.tare();
 
  
  // Initialize RTC
  rtc.begin();
 
  // Initialize SD card
  SD.begin(CS_PIN);
 
}

void loop() {
  if (millis() - lastMeasurement >= measureInterval) {
    float weight = scale.get_units();
    DateTime now = rtc.now();
    
    // Start logging if weight exceeds threshold
    if (weight > threshold && !isLogging) {
      String filename = String(now.year()) + String(now.month()) + String(now.day()) + "_" + 
                       String(now.hour()) + String(now.minute()) + ".csv";
      ispFile = SD.open("myData.txt", FILE_WRITE);
      ispFile.println("Time,Weight(kg)");
      isLogging = true;
    }
    
    // Continue logging while weight is above threshold
    if (isLogging) {
      if (weight > threshold) {
        String dataString = String(now.timestamp()) + "," + String(weight, 3);
        ispFile.println(dataString);
        ispFile.flush();
      } else {
        // Stop logging when weight drops below threshold
        ispFile.close();
        isLogging = false;
      }
    }
    
    lastMeasurement = millis();
  }
}