Sensor Template

Sensor information on the server

Each device (sensor) needs to have the relevant section updated in the config on the server. This is the example section for the sensors in this repository.

{
  "hostname": "rpi",
  "username": "vti",
  "mac_address": "2c:cf:67:28:80:0a",
  "registration": "2024-09-02T11:53:49.694564Z",
  "sensors": [
    {
      "args": [
        "--upload-interval",
        "5"
      ],
      "entry_point": "radar.py",
      "git_url": "https://github.com/jsliacan/sensors.git",
      "git_version": "varia",
      "name": "VTIGarminVariaRCT716"
    },
    {
      "args": [
        "--upload-interval",
        "5"
      ],
      "entry_point": "lidar.py",
      "git_url": "https://github.com/jsliacan/sensors.git",
      "git_version": "varia",
      "name": "VTIGarminLidarLiteV3"
    },
    {
      "args": [
        "--upload-interval",
        "5"
      ],
      "entry_point": "button.py",
      "git_url": "https://github.com/jsliacan/sensors.git",
      "git_version": "varia",
      "name": "VTIButton"
    }
  ],
  "project": "validation",
  "model": "CardiLidar"
}

Backing up data onto USB-storage

It is possible to copy the data files at regular intervals during the activity to a USB storage attached to the RPi. This line should do it:

    shutil.copyfile(filename, "/media/vti/bikedata/"+filename.split("/")[-1])

Clearly, there are caveats.

1. The USB needs to be attached, otherwise this will crash the process.
2. Make sure to format USB device as ext4 and put a filesystem on it. The code expects the USB to be bikedata and mounts to /media/vti/bikedata on the RPi. I used Disk Utility on Fedora and once I formatted the USB disk I created a partition called bikedata on it (ext4 type). That's it.

Getting Started

Prerequisites

• Python 3.x: Ensure you have Python 3 installed on your system.
• Dependencies: The framework uses the requests module for handling HTTP requests. You can install it using:

pip install requests

Installation

Clone the repository to your local machine:

git clone https://github.com/bicycledata/sensor_template.git
cd sensor_template

Usage

To create a custom bicycle sensor, extend the BicycleSensor class and implement the abstract methods: write_header() and write_measurement(). The provided SensorTemplate class serves as an example implementation that records the current time as a sensor measurement.

Example:

class MyCustomSensor(BicycleSensor):
    def write_header(self):
        self.write_to_file('time, speed')

    def write_measurement(self):
        speed = get_speed_data()  # Replace with actual sensor logic
        self.write_to_file(f"{time.time()}, {speed}")

Example Usage

You can run the provided SensorTemplate class with the following command:

./sensor.py --hash <device_hash> --name <sensor_name> [options]

Command-Line Arguments

• --hash (required): The unique hash of the device, used for identifying the sensor during uploads.
• --name (required): The name of the sensor.
• --loglevel (optional): Set the logging level (DEBUG, INFO, WARNING). Default is INFO.
• --measurement-frequency (optional): Frequency of sensor measurements in Hertz (measurements per second). Default is 1.0 Hz.
• --stdout (optional): Enable logging output to the console (stdout).
• --upload-interval (optional): Interval between data uploads in seconds. Default is 300 seconds (5 minutes).

Framework Details

The framework handles the following operations:

• File Management: Data is written to CSV files stored in the pending directory. Upon successful upload, files are moved to the uploaded directory.
• Data Upload: Data is uploaded to a remote server (configured in the _upload_data method) using HTTP POST requests. The upload logic is executed in a separate thread to ensure that the main sensor loop runs without interruptions.
• Signal Handling: The framework gracefully handles shutdown signals (SIGTERM, SIGINT) and ensures that any pending data is uploaded before exiting.

Logging

Logging is configured through the configure() function. The framework supports:

• File-based logging: Logs are stored in the log/sensor_template.log file.
• Rotating logs: By enabling the rotating option, logs are rotated when they reach 5MB in size, with a backup count of 2.
• Console output: Enable logging to the console using the --stdout flag.

Data Upload

The framework's automated upload feature sends sensor data to the server at regular intervals. The upload process is managed by a separate thread, ensuring it does not interfere with data collection. The upload endpoint and payload are defined in the _upload_data() method.

Note: If the upload fails, the data remains in the pending directory and the framework retries in the next cycle.

Contributing

Contributions are welcome! If you have suggestions for improvements or find any bugs, feel free to open an issue or submit a pull request.

License

This repository is licensed under the MIT License. See the LICENSE file for more details.