example: add support for csv

Signed-off-by: YoungSoo Shin <shinys000114@gmail.com>

example/logger/logger.py

@@ -1,11 +1,13 @@
 import argparse
 import asyncio
+import csv
 import requests
+import websockets
+from datetime import datetime
+
 # Import the status_pb2.py file generated by `protoc`.
 # This file must be in the same directory as logger.py.
 import status_pb2
-import websockets
-from datetime import datetime
 
 
 class OdroidPowerLogger:
@@ -16,12 +18,13 @@ class OdroidPowerLogger:
     3. Receives and decodes binary data in Protobuf format, then prints it.
     """
 
-    def __init__(self, host, username, password):
+    def __init__(self, host, username, password, output_file=None):
         self.host = host
         self.username = username
         self.password = password
         self.base_url = f"http://{self.host}"
         self.ws_url = f"ws://{self.host}/ws"
+        self.output_file = output_file
         self.token = None
 
     def login(self):
@@ -54,7 +57,33 @@ class OdroidPowerLogger:
         # Add the authentication token as a query parameter
         uri = f"{self.ws_url}?token={self.token}"
 
+        csv_file = None
+        csv_writer = None
+
         try:
+            # --- CSV File Handling ---
+            if self.output_file:
+                try:
+                    # Open the file in write mode, with newline='' to prevent extra blank rows
+                    csv_file = open(self.output_file, 'w', newline='', encoding='utf-8')
+                    csv_writer = csv.writer(csv_file)
+
+                    # Write header
+                    header = [
+                        'timestamp', 'uptime_sec',
+                        'vin_voltage', 'vin_current', 'vin_power',
+                        'main_voltage', 'main_current', 'main_power',
+                        'usb_voltage', 'usb_current', 'usb_power'
+                    ]
+                    csv_writer.writerow(header)
+                    print(f"Logging data to {self.output_file}")
+                except IOError as e:
+                    print(f"Error opening CSV file: {e}")
+                    # If file can't be opened, disable CSV writing
+                    csv_file = None
+                    csv_writer = None
+            # --- End CSV File Handling ---
+
             async with websockets.connect(uri) as websocket:
                 print(f"Connected to WebSocket: {uri}")
                 while True:
@@ -68,9 +97,10 @@ class OdroidPowerLogger:
                     # Process only if the payload type is 'sensor_data'
                     if status_message.WhichOneof('payload') == 'sensor_data':
                         sensor_data = status_message.sensor_data
-                        ts = datetime.fromtimestamp(sensor_data.timestamp).strftime('%Y-%m-%d %H:%M:%S')
+                        ts_dt = datetime.fromtimestamp(sensor_data.timestamp)
+                        ts_str = ts_dt.strftime('%Y-%m-%d %H:%M:%S')
 
-                        print(f"--- {ts} (Uptime: {sensor_data.uptime_sec}s) ---")
+                        print(f"--- {ts_str} (Uptime: {sensor_data.uptime_sec}s) ---")
 
                         # Print data for each channel
                         for name, channel in [('VIN', sensor_data.vin), ('MAIN', sensor_data.main),
@@ -78,10 +108,24 @@ class OdroidPowerLogger:
                             print(
                                 f"  {name:<4}: {channel.voltage:5.2f} V | {channel.current:5.3f} A | {channel.power:5.2f} W")
 
+                        # Write to CSV if enabled
+                        if csv_writer:
+                            row = [
+                                ts_dt.isoformat(), sensor_data.uptime_sec,
+                                sensor_data.vin.voltage, sensor_data.vin.current, sensor_data.vin.power,
+                                sensor_data.main.voltage, sensor_data.main.current, sensor_data.main.power,
+                                sensor_data.usb.voltage, sensor_data.usb.current, sensor_data.usb.power
+                            ]
+                            csv_writer.writerow(row)
+
         except websockets.exceptions.ConnectionClosed as e:
             print(f"WebSocket connection closed: {e}")
         except Exception as e:
             print(f"Error during WebSocket processing: {e}")
+        finally:
+            if csv_file:
+                csv_file.close()
+                print(f"\nCSV file '{self.output_file}' saved.")
 
     async def run(self):
         """Runs the logger."""
@@ -94,9 +138,10 @@ async def main():
     parser.add_argument("host", help="Server's host address or IP (e.g., 192.168.1.10)")
     parser.add_argument("-u", "--username", required=True, help="Login username")
     parser.add_argument("-p", "--password", required=True, help="Login password")
+    parser.add_argument("-o", "--output", help="Path to the output CSV file.")
     args = parser.parse_args()
 
-    logger = OdroidPowerLogger(host=args.host, username=args.username, password=args.password)
+    logger = OdroidPowerLogger(host=args.host, username=args.username, password=args.password, output_file=args.output)
     await logger.run()