Conditional cloud sync

You may want to sync data only when a certain logic condition is met, instead of at a regular time interval. For example, if you rely on mobile data but have intermittent WiFi connection in certain locations or at certain times of the day, you may want to trigger sync to only occur when these conditions are met. Or, you may want to trigger sync only when your machine detects an object of a certain color. You can use the trigger-sync-examples module if one of these examples is what you are looking for.

If you need different logic, you can create a modular sensor that determines if the conditions for sync are met or not. This guide will show you the implementation of a sensor which only allows sync during a defined time interval. You can use it as the basis of your own custom logic.

Prerequisites

Return should_sync as a reading from a sensor

If the builtin data manager is configured with a sync sensor, the data manager will check the sensor’s Readings method for a response with a “should_sync” key.

The following example returns "should_sync": true if the current time is in a specified time window, and "should_sync": false otherwise.

func (s *timeSyncer) Readings(context.Context, map[string]interface{}) (map[string]interface{}, error) {
    currentTime := time.Now()
    var hStart, mStart, sStart, hEnd, mEnd, sEnd int
    n, err := fmt.Sscanf(s.start, "%d:%d:%d", &hStart, &mStart, &sStart)

    if err != nil || n != 3 {
        s.logger.Error("Start time is not in the format HH:MM:SS.")
        return nil, err
    }
    m, err := fmt.Sscanf(s.end, "%d:%d:%d", &hEnd, &mEnd, &sEnd)
    if err != nil || m != 3 {
        s.logger.Error("End time is not in the format HH:MM:SS.")
        return nil, err
    }

    zone, err := time.LoadLocation(s.zone)
    if err != nil {
        s.logger.Error("Time zone cannot be loaded: ", s.zone)
    }

    startTime := time.Date(currentTime.Year(), currentTime.Month(), currentTime.Day(),
        hStart, mStart, sStart, 0, zone)
    endTime := time.Date(currentTime.Year(), currentTime.Month(), currentTime.Day(),
        hEnd, mEnd, sEnd, 0, zone)

    readings := map[string]interface{}{"should_sync": false}
    readings["time"] = currentTime.String()
    // If it is between the start and end time, sync.
    if currentTime.After(startTime) && currentTime.Before(endTime) {
        s.logger.Debug("Syncing")
        readings["should_sync"] = true
        return readings, nil
    }

    // Otherwise, do not sync.
    s.logger.Debug("Not syncing. Current time not in sync window: " + currentTime.String())
    return readings, nil
}

If you wish to see more context, see the entire implementation of the sensor on GitHub.

For additional examples, see the Readings function of the time-interval-trigger code and the color-trigger code.

Add your sensor to determine when to sync

Add your module to your machine and configure it. In this example we will continue to use sync-at-time:timesyncsensor. You will need to follow the same steps with your module:

{
  "start": "HH:MM:SS",
  "end": "HH:MM:SS",
  "zone": "<TIMEZONE>"
}

{
  "start": "18:29:00",
  "end": "18:30:00",
  "zone": "CET"
}

In the next step you will configure the data manager to take the sensor into account when syncing.

Configure the data manager to sync based on sensor

On your machine’s CONFIGURE tab, switch to JSON mode and add a selective_syncer_name with the name for the sensor you configured and add the sensor to the depends_on field:

{
  "name": "data_manager-1",
  "type": "data_manager",
  "namespace": "rdk",
  "attributes": {
    "additional_sync_paths": [],
    "capture_dir": "",
    "capture_disabled": false,
    "selective_syncer_name": "<SENSOR-NAME>",
    "sync_disabled": false,
    "sync_interval_mins": 0.1,
    "tags": []
  },
  "depends_on": ["<SENSOR-NAME>"]
}

{
  "name": "datamanager",
  "type": "data_manager",
  "namespace": "rdk",
  "attributes": {
    "additional_sync_paths": [],
    "selective_syncer_name": "timesensor",
    "sync_interval_mins": 0.1,
    "capture_dir": "",
    "tags": []
  },
  "depends_on": ["timesensor"]
}

{
  "components": [
    {
      "name": "camera-1",
      "namespace": "rdk",
      "type": "camera",
      "model": "webcam",
      "attributes": {
        "video_path": "0x114000005a39331"
      }
    },
    {
      "name": "timesensor",
      "namespace": "rdk",
      "type": "sensor",
      "model": "naomi:sync-at-time:timesyncsensor",
      "attributes": {
        "start": "18:29:00",
        "end": "18:30:00",
        "zone": "CET"
      }
    }
  ],
  "services": [
    {
      "name": "data_manager-1",
      "namespace": "rdk",
      "type": "data_manager",
      "attributes": {
        "capture_dir": "",
        "tags": [],
        "additional_sync_paths": [],
        "selective_syncer_name": "timesensor",
        "sync_interval_mins": 0.1
      },
      "depends_on": ["timesensor"]
    }
  ],
  "modules": [
    {
      "type": "registry",
      "name": "naomi_sync-at-time",
      "module_id": "naomi:sync-at-time",
      "version": "2.0.0"
    }
  ]
}

You have now configured sync to happen during a specific time slot.

Test your sync configuration

To test your setup, configure a webcam or another component and enable data capture on the component. Make sure to physically connect any hardware parts to the computer controlling your machine. For a camera component, use the ReadImage method. The data manager will now capture data. Go to the CONTROL tab. You should see the sensor. Click on GetReadings.

If you are in the time frame for sync, the time sync sensor will return true.

You can confirm that if data is currently syncing by going to the Data tab. If you are not in the time frame for sync, adjust the configuration of your time sync sensor. Then check again on the CONTROL and Data tab to confirm data is syncing.

Next steps

You can now use custom logic to trigger sync conditionally. For more information, see:

Create a sensor module with Python

Add a new model of sensor component by writing a module in Python.

Create a module

Add support for a new component or service model by writing a module.

Sync Trigger Examples

Other example code for modules that trigger sync.