update logger README to include detailed usage instructions and examples

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

example/logger/README.md

@@ -1,46 +1,140 @@
-# Power Consumption Logger Example
+# Odroid PowerMate Logger and Plotter
 
-Based on this script, you can monitor power consumption and implement graph plotting.
+This directory contains two Python scripts to log power data from an Odroid PowerMate device and visualize it.
 
-## How to Run the Script
+1.  `logger.py`: Connects to the device's web server, authenticates, and logs real-time power data from its WebSocket to a CSV file.
+2.  `csv_2_plot.py`: Reads the generated CSV file and creates a plot image of the power, voltage, and current data over time.
 
-### Install Python Virtual Environment
+## Prerequisites
 
-```shell
+### 1. Clone this example
+```bash
 git clone https://github.com/hardkernel/odroid-powermate.git
 cd odroid-powermate/example/logger
 ```
 
-```shell
+### 2. Python and Virtual Environment
-sudo apt install virtualenv
+
-virtualenv venv
+It is highly recommended to use a Python virtual environment to manage project dependencies and avoid conflicts with other projects.
-source venv/bin/activate
+
+Ensure you have Python 3 installed.
+
+1.  **Create a virtual environment:**
+    Open your terminal in this directory and run:
+    ```bash
+    python3 -m venv venv
+    ```
+    This will create a `venv` directory containing the Python interpreter and libraries.
+
+2.  **Activate the virtual environment:**
+    *   **On Windows:**
+        ```powershell
+        .\venv\Scripts\activate
+        ```
+    *   **On macOS and Linux:**
+        ```bash
+        source venv/bin/activate
+        ```
+    Your terminal prompt should now show `(venv)` at the beginning, indicating that the virtual environment is active.
+
+### 3. Install Required Libraries
+
+With the virtual environment activated, install the necessary Python packages:
+
+```bash
+pip3 install requests websockets protobuf pandas matplotlib python-dateutil
 ```
 
-### Install require package
+### 4. Protobuf Generated File
 
-```shell
+The `logger.py` script uses Google Protocol Buffers (Protobuf) to decode real-time data from the WebSocket. This requires a Python file, `status_pb2.py`, which is generated from a Protobuf definition file (`status.proto`).
-pip install grpcio-tools requests websockets protobuf pandas matplotlib
+
+**How to Generate `status_pb2.py`:**
+
+1.  **Install Protobuf Compiler Tools:**
+    You need the `grpcio-tools` package, which includes the `protoc` compiler and Python plugins. You can install it via pip:
+    ```bash
+    pip3 install grpcio-tools
+    ```
+
+2.  **Locate the `.proto` file:**
+    Ensure you have the `status.proto` file in the current directory. This file defines the structure of the data messages.
+
+3.  **Run the Compiler:**
+    Execute the following command in your terminal. This command tells `protoc` to look for `status.proto` in the directory (`-I../../proto`) and generate the Python output file (`--python_out=.`) in the same place.
+    ```bash
+    python3 -m grpc_tools.protoc -I../../proto --python_out=. status.proto
+    ```
+After running this command, the `status_pb2.py` file will be created, and `logger.py` will be able to use it.
+
+## Usage
+
+The process is a two-step workflow: first log the data, then plot it.
+
+### Step 1: Log Power Data with `logger.py`
+
+Run `logger.py` to connect to your Odroid Smart Power device and save the data to a CSV file.
+
+**Syntax:**
+```bash
+python3 logger.py <host> -u <username> -p <password> -o <output_file.csv>
 ```
 
-### Build `status_pb2.py`
+**Arguments:**
+*   `host`: The IP address or hostname of the Odroid Smart Power device (e.g., `192.168.1.50`).
+*   `-u`, `--username`: The username for logging in.
+*   `-p`, `--password`: The password for logging in.
+*   `-o`, `--output`: The path to save the output CSV file. This is required if you want to generate a plot.
 
-```shell
+**Example:**
-python -m grpc_tools.protoc -I ../../proto --python_out=. status.proto
+
+This command will log in and save the power data to `power_log.csv`.
+
+```bash
+python3 logger.py 192.168.1.50 -u admin -p mypassword -o power_log.csv
 ```
 
-### Execute script
+The script will continue to log data until you stop it with `Ctrl+C`.
 
-#### Power consumption collection
+### Step 2: Generate a Plot with `csv_2_plot.py`
-```shell
+
-# python3 logger.py -u <username> -o <name.csv> -p <password> <address>
+Once you have a CSV log file, you can use `csv_2_plot.py` to create a visual graph.
-python3 logger.py -u admin -p password -o test.csv 192.168.30.5 
+You can also use the csv file recorded from PowerMate Web.
+
+**Syntax:**
+```bash
+python3 csv_2_plot.py <input.csv> <output.png> [options]
 ```
 
-#### Plot data
+**Arguments:**
+*   `input_csv`: The path to the CSV file generated by `logger.py`.
+*   `output_image`: The path to save the output plot image (e.g., `plot.png`).
 
-```shell
+**Optional Arguments:**
-python3 csv_2_plot.py test.csv plot.png [--type power voltage current] [--source vin main usb]
+*   `-t`, `--type`: Specify which plots to generate. Choices are `power`, `voltage`, `current`. Default is all three.
+*   `-s`, `--source`: Specify which power sources to include. Choices are `vin`, `main`, `usb`. Default is all three.
+
+**Example 1: Default Plot**
+
+This command reads `power_log.csv` and generates a plot containing power, voltage, and current for all sources, saving it as `power_graph.png`.
+
+```bash
+python3 csv_2_plot.py power_log.csv power_graph.png
 ```
 
-![plot.png](plot.png)
+**Example 2: Custom Plot**
+
+This command generates a plot showing only the **power** and **current** for the **MAIN** and **USB** sources.
+
+```bash
+# main, usb power consumption
+python csv_2_plot.py power_log.csv custom_plot.png --type power --source main usb
+```
+
+## Example Output
+
+Running the plot script will generate an image file similar to this:
+
+![plot.png](img/plot.png)
+
+The 5-unit scale is highlighted with a blue dotted line, and the 10-unit scale is highlighted with a red dotted line.

example/logger/csv_2_plot.py

@@ -3,6 +3,7 @@ import matplotlib.dates as mdates
 import matplotlib.pyplot as plt
 import pandas as pd
 from dateutil.tz import gettz
+from matplotlib.ticker import MultipleLocator
 
 
 def plot_power_data(csv_path, output_path, plot_types, sources):
@@ -19,16 +20,11 @@ def plot_power_data(csv_path, output_path, plot_types, sources):
     """
     try:
         # Read the CSV file into a pandas DataFrame
-        # The 'timestamp' column is parsed as dates. Pandas automatically recognizes
-        # the ISO format (with 'Z') as UTC.
         df = pd.read_csv(csv_path, parse_dates=['timestamp'])
         print(f"Successfully loaded {len(df)} records from '{csv_path}'")
 
         # --- Timezone Conversion ---
-        # Get the system's local timezone
         local_tz = gettz()
-        # The timestamp from CSV is already UTC-aware.
-        # Convert it to the system's local timezone for plotting.
         df['timestamp'] = df['timestamp'].dt.tz_convert(local_tz)
         print(f"Timestamp converted to local timezone: {local_tz}")
 
@@ -39,24 +35,32 @@ def plot_power_data(csv_path, output_path, plot_types, sources):
         print(f"An error occurred while reading the CSV file: {e}")
         return
 
+    # --- Calculate Average Interval ---
+    avg_interval_ms = 0
+    if len(df) > 1:
+        avg_interval = df['timestamp'].diff().mean()
+        avg_interval_ms = avg_interval.total_seconds() * 1000
+
+    # --- Calculate Average Voltages ---
+    avg_voltages = {}
+    for source in sources:
+        voltage_col = f'{source}_voltage'
+        if voltage_col in df.columns:
+            avg_voltages[source] = df[voltage_col].mean()
+
     # --- Plotting Configuration ---
-    # Y-axis scale settings from chart.js
     scale_config = {
         'power': {'steps': [5, 20, 50, 160]},
         'voltage': {'steps': [5, 10, 15, 25]},
         'current': {'steps': [1, 2.5, 5, 10]}
     }
-
     plot_configs = {
-        'power': {'title': 'Power Consumption', 'ylabel': 'Power (W)',
+        'power': {'title': 'Power Consumption', 'ylabel': 'Power (W)', 'cols': [f'{s}_power' for s in sources]},
-                  'cols': [f'{s}_power' for s in sources]},
+        'voltage': {'title': 'Voltage', 'ylabel': 'Voltage (V)', 'cols': [f'{s}_voltage' for s in sources]},
-        'voltage': {'title': 'Voltage', 'ylabel': 'Voltage (V)',
+        'current': {'title': 'Current', 'ylabel': 'Current (A)', 'cols': [f'{s}_current' for s in sources]}
-                    'cols': [f'{s}_voltage' for s in sources]},
-        'current': {'title': 'Current', 'ylabel': 'Current (A)',
-                    'cols': [f'{s}_current' for s in sources]}
     }
+
     channel_labels = [s.upper() for s in sources]
-    # Define a color map for all possible sources
     color_map = {'vin': 'red', 'main': 'green', 'usb': 'blue'}
     channel_colors = [color_map[s] for s in sources]
 
@@ -65,20 +69,17 @@ def plot_power_data(csv_path, output_path, plot_types, sources):
         print("No plot types selected. Exiting.")
         return
 
-    # Create a figure and a set of subplots based on the number of selected plot types.
+    fig, axes = plt.subplots(num_plots, 1, figsize=(15, 9 * num_plots), sharex=True, squeeze=False)
-    fig, axes = plt.subplots(num_plots, 1, figsize=(15, 6 * num_plots), sharex=True, squeeze=False)
+    axes = axes.flatten()
-    axes = axes.flatten()  # Flatten the 2D array to 1D for easier iteration
 
     # --- Loop through selected plot types and generate plots ---
     for i, plot_type in enumerate(plot_types):
         ax = axes[i]
         config = plot_configs[plot_type]
-
         max_data_value = 0
         for j, col_name in enumerate(config['cols']):
             if col_name in df.columns:
-                ax.plot(df['timestamp'], df[col_name], label=channel_labels[j], color=channel_colors[j])
+                ax.plot(df['timestamp'], df[col_name], label=channel_labels[j], color=channel_colors[j], zorder=2)
-                # Find the maximum value in the current column to set the y-axis limit
                 max_col_value = df[col_name].max()
                 if max_col_value > max_data_value:
                     max_data_value = max_col_value
@@ -86,34 +87,82 @@ def plot_power_data(csv_path, output_path, plot_types, sources):
                 print(f"Warning: Column '{col_name}' not found in CSV. Skipping.")
 
         # --- Dynamic Y-axis Scaling ---
-        ax.set_ylim(bottom=0) # Set y-axis minimum to 0
+        ax.set_ylim(bottom=0)
         if plot_type in scale_config:
             steps = scale_config[plot_type]['steps']
-            # Find the smallest step that is >= max_data_value
             new_max = next((step for step in steps if step >= max_data_value), steps[-1])
             ax.set_ylim(top=new_max)
 
         ax.set_title(config['title'])
         ax.set_ylabel(config['ylabel'])
         ax.legend()
-        ax.grid(True, which='both', linestyle='--', linewidth=0.5)
+
+        # --- Grid and Tick Configuration ---
+        y_min, y_max = ax.get_ylim()
+
+        # Keep the dynamic major_interval logic for tick LABELS
+        if plot_type == 'current' and y_max <= 2.5:
+            major_interval = 0.5
+        elif y_max <= 10:
+            major_interval = 2
+        elif y_max <= 25:
+            major_interval = 5
+        else:
+            major_interval = y_max / 5.0
+
+        ax.yaxis.set_major_locator(MultipleLocator(major_interval))
+        ax.yaxis.set_minor_locator(MultipleLocator(1))
+
+        # Disable the default major grid, but keep the minor one
+        ax.yaxis.grid(False, which='major')
+        ax.yaxis.grid(True, which='minor', linestyle='--', linewidth=0.6, zorder=0)
+
+        # Draw custom lines for 5 and 10 multiples, which are now the only major grid lines
+        for y_val in range(int(y_min), int(y_max) + 1):
+            if y_val == 0: continue
+            if y_val % 10 == 0:
+                ax.axhline(y=y_val, color='maroon', linestyle='--', linewidth=1.2, zorder=1)
+            elif y_val % 5 == 0:
+                ax.axhline(y=y_val, color='midnightblue', linestyle='--', linewidth=1.2, zorder=1)
+
+        # Keep the x-axis grid
+        ax.xaxis.grid(True, which='major', linestyle='--', linewidth=0.8)
 
     # --- Formatting the x-axis (Time) ---
     local_tz = gettz()
     last_ax = axes[-1]
-    # Pass the timezone to the formatter
+
+    if not df.empty:
+        last_ax.set_xlim(df['timestamp'].iloc[0], df['timestamp'].iloc[-1])
+
     last_ax.xaxis.set_major_formatter(mdates.DateFormatter('%H:%M:%S', tz=local_tz))
-    last_ax.xaxis.set_major_locator(plt.MaxNLocator(15))  # Limit the number of ticks
+    last_ax.xaxis.set_major_locator(plt.MaxNLocator(15))
-    plt.xlabel(f'Time ({local_tz.tzname(df["timestamp"].iloc[-1])})') # Display timezone name
+    plt.xlabel(f'Time ({local_tz.tzname(df["timestamp"].iloc[-1])})')
     plt.xticks(rotation=45)
 
-    # Add a main title to the figure
+    # --- Add a main title and subtitle ---
     start_time = df['timestamp'].iloc[0].strftime('%Y-%m-%d %H:%M:%S')
     end_time = df['timestamp'].iloc[-1].strftime('%H:%M:%S')
-    fig.suptitle(f'PowerMate Log ({start_time} to {end_time})', fontsize=16, y=0.95)
+    main_title = f'PowerMate Log ({start_time} to {end_time})'
 
-    # Adjust layout to prevent titles/labels from overlapping
+    subtitle_parts = []
-    plt.tight_layout(rect=[0, 0, 1, 0.94])
+    if avg_interval_ms > 0:
+        subtitle_parts.append(f'Avg. Interval: {avg_interval_ms:.2f} ms')
+
+    voltage_strings = [f'{source.upper()} Avg: {avg_v:.2f} V' for source, avg_v in avg_voltages.items()]
+    if voltage_strings:
+        subtitle_parts.extend(voltage_strings)
+
+    subtitle = ' | '.join(subtitle_parts)
+
+    full_title = main_title
+    if subtitle:
+        full_title += f'\n{subtitle}'
+
+    fig.suptitle(full_title, fontsize=14)
+
+    # Adjust layout to make space for the subtitle
+    plt.tight_layout(rect=[0, 0, 1, 0.98])
 
     # --- Save the plot to a file ---
     try:

example/logger/logger.py

@@ -3,7 +3,7 @@ import asyncio
 import csv
 import requests
 import websockets
-from datetime import datetime
+from datetime import datetime, timezone
 
 # Import the status_pb2.py file generated by `protoc`.
 # This file must be in the same directory as logger.py.
@@ -68,7 +68,7 @@ class OdroidPowerLogger:
                     csv_file = open(self.output_file, 'w', newline='', encoding='utf-8')
                     csv_writer = csv.writer(csv_file)
 
-                    # Write header - matches main.js and csv_2_plot.py expectations
+                    # Write header
                     header = [
                         'timestamp', 'uptime_ms',
                         'vin_voltage', 'vin_current', 'vin_power',
@@ -97,24 +97,22 @@ 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_dt = datetime.fromtimestamp(sensor_data.timestamp_ms / 1000, tz=timezone.utc)
-                        # Format timestamp to ISO format with 'Z' for UTC, matching main.js
+                        ts_str_print = ts_dt.strftime('%Y-%m-%d %H:%M:%S UTC')
-                        ts_dt = datetime.fromtimestamp(sensor_data.timestamp_ms / 1000)
-                        ts_iso = ts_dt.isoformat(timespec='milliseconds') + 'Z'
 
-                        # Print data for console output (can be adjusted if needed)
+                        print(f"--- {ts_str_print} (Uptime: {sensor_data.uptime_ms / 1000}s) ---")
-                        print(f"--- {ts_iso} (Uptime: {sensor_data.uptime_ms / 1000:.3f}s) ---")
+
+                        # Print data for each channel
                         for name, channel in [('VIN', sensor_data.vin), ('MAIN', sensor_data.main),
                                               ('USB', sensor_data.usb)]:
                             print(
-                                f"  {name:<4}: {channel.voltage:.3f} V | {channel.current:.3f} A | {channel.power:.3f} W")
+                                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:
-                            # Format numerical values to 3 decimal places, matching main.js
+                            ts_iso_csv = ts_dt.isoformat(timespec='milliseconds').replace('+00:00', 'Z')
                             row = [
-                                ts_iso,
+                                ts_iso_csv, sensor_data.uptime_ms,
-                                sensor_data.uptime_ms,
                                 f"{sensor_data.vin.voltage:.3f}", f"{sensor_data.vin.current:.3f}", f"{sensor_data.vin.power:.3f}",
                                 f"{sensor_data.main.voltage:.3f}", f"{sensor_data.main.current:.3f}", f"{sensor_data.main.power:.3f}",
                                 f"{sensor_data.usb.voltage:.3f}", f"{sensor_data.usb.current:.3f}", f"{sensor_data.usb.power:.3f}"