import serial
import csv
import time
from datetime import datetime

# Configure the serial port
ser = serial.Serial('/dev/ttyS0', baudrate=9600, timeout=1)

# Open the CSV file for writing
csv_filename = 'gps_data.csv'
csv_file = open(csv_filename, 'w', newline='')
csv_writer = csv.writer(csv_file)

# Write the header row
csv_writer.writerow(['Timestamp', 'Latitude', 'Longitude'])

try:
    while True:
        # Read a line from the GPS device
        line = ser.readline().decode('ascii', errors='replace').strip()
        
        # Check if it's a GPRMC sentence (which contains coordinate data)
        if line.startswith('$GPRMC'):
            parts = line.split(',')
            if len(parts) >= 7 and parts[2] == 'A':  # 'A' means data is valid
                # Extract latitude and longitude
                lat = float(parts[3][:2]) + float(parts[3][2:]) / 60
                if parts[4] == 'S':
                    lat = -lat
                lon = float(parts[5][:3]) + float(parts[5][3:]) / 60
                if parts[6] == 'W':
                    lon = -lon
                
                # Get current timestamp
                timestamp = datetime.now().isoformat()
                
                # Write to CSV
                csv_writer.writerow([timestamp, lat, lon])
                csv_file.flush()  # Ensure data is written to file
                
                print(f"Recorded: {timestamp}, Lat: {lat}, Lon: {lon}")
        
        time.sleep(1)  # Wait for 1 second before reading next line

except KeyboardInterrupt:
    print("Script terminated by user")

finally:
    # Close the serial port and CSV file
    ser.close()
    csv_file.close()
    print(f"Data saved to {csv_filename}")