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One of the most common and valuable use cases for IoT is asset tracking. Whether for a vehicle, trailer, or shipping container, asset tracking is a powerful way for developers and companies to understand where an asset has been, where it is, and where it’s headed; all while monitoring the conditions of the asset itself.

The Cellular Notecard package contains nearly everything you need to build a cellular-powered asset tracker. This guide provides instructions for configuring your Notecard as a standalone asset tracker as well as an MCU host-controlled tracker.

This guide provides instructions for using the Notecard as both a standalone tracker, and with an MCU host. For both approaches, you’ll need the following:

  • A Cellular Notecard.
  • A Notecarrier with Cellular and GPS/GNSS antennas, and battery support. The Notecarrier-A and Notecarrier-AF have both antennas on-board, and provide a connector for a LiPo battery.
  • A Micro USB cable.

If you’re building a standalone Notecard tracker, you’ll need the following:

  • The Notecard CLI or the provided browser-based serial terminal for configuring the Notecard.

If you’re building a host-driven tracker, you’ll need the following:

  • A microcontroller or single-board computer for communicating with the Notecard. The code samples in this guide target the Feather-compatible Swan running Arduino code, but can easily be adapted for your board of choice.
  • Optional: An external sensor for gathering additional information about your asset. This guide uses a Bosch BME680 temperature and humidity sensor.
  • A text editor for writing firmware, such as the Arduino IDE or VS Code .

To configure your Notecard as a tracker, you’ll need to do the following:

  • Perform a factory restore on the Notecard. This step is optional, but recommended as card.restore will perform a factory reset on the Notecard and clear out Notes and Notefiles from previous applications. Setting "delete":true will also clear out all configuration settings.

    {"req":"card.restore","delete":true}

  • Set a Product UID, mode, and sync times with hub.set. periodic is recommended for cases where your tracker will need to operate on battery power for extended periods of time. The outbound and inbound fields specify the interval, in minutes, that the Notecard should process outbound and inbound requests. These values also affect battery life, so use a value that makes sense for your application’s power and data sync needs. The Notecard will only sync on the outbound interval if un-synced tracking information is available, but will always sync on the inbound interval in order to process new Notes and environment variables from Notehub.

    {
  "req":      "hub.set",
  "product":  "com.veritas.delivery-fleet.tracker",
  "mode":     "periodic",
  "outbound": 60,
  "inbound":  720
}

  • Set the Notecard to use periodic or continuous location mode. periodic is recommended for battery-powered applications, and continuous for cases where low-latency location tracking is needed and power consumption is not a concern. When using periodic, the seconds field defines the interval at which to activate GPS and capture a location sample. Note: When in periodic mode, the GPS module will only activate to take a reading if the Notecard detects movement through its onboard accelerometer between interval periods.

    {
  "req":     "card.location.mode",
  "mode":    "periodic",
  "seconds": 3600
}

  • Configure the Notecard to store tracking results in a tracking file that will be synced to Notehub, and set a heartbeat to check-in even if the device has not moved. card.location.track will store tracking-related data like location and temperature (as well as velocity, bearing, and distance if card.location.mode is set to mode:continuous, or mode:periodic and seconds < 300). This data is saved in a Notefile that will be sent to Notehub on each sync. The default file is _motion.qo, but you can specify your own name with the file field. If you anticipate that your asset may be stationary for long periods of time, you can use heartbeat and hours to instruct the Notecard to create a tracking entry at a defined interval, regardless of motion. The Notecard does not switch on the GPS for heartbeats, since no movement has occurred. However the heartbeat provides confirmation that the Notecard tracker is still functioning correctly.

    {
  "req":       "card.location.track",
  "start":     true,
  "heartbeat": true,
  "hours":     12
}

Once these requests have been sent to the Notecard, your tracker is ready to be deployed! The following two sections provide the specific steps for sending these requests for a standalone or host-controlled tracker.

To further customize your tracker, you can consult the Advanced Tracker Configuration section below.

note

The above commands will only work if the Notecard accelerometer is enabled. The {"req":"card.restore","delete":true} request enables the accelerometer, or it can be enabled with the following request if previously disabled.

{"req":"card.motion.mode","start":true}

There are times where you simply want to track the location of your Notecard-connected asset and don’t need to gather data from an external sensor, or control how and when your Notecard should track and sync after deployment. In these cases, you can configure your Notecard as a standalone tracker by issuing a few requests from a connected computer, connect a battery, and deploy it to the asset to be tracked.

The fastest way to configure the Notecard in this way is with the Notecard CLI, which allows you to connect to a Notecard over USB Serial and issue requests. The requests above can be sent individually using the req or play flag, or you can place all of the requests into a file with a json extension and use the setup flag to send them all at once. This is a handy approach when configuring multiple trackers for deployment.

notecard -setup configure-standalone-tracker.json

The Notecard will send each request in turn and output the result, like so:

{"req":"card.restore","delete":true}
{}

{"req":"hub.set","product":"com.veritas.delivery-fleet.tracker","mode":"periodic","outbound":60,"inbound":720}
{}

{"req":"card.location.mode","seconds":3600,"mode":"periodic"}
{"seconds":3600,"mode":"periodic"}

{"req":"card.location.track","start":true,"heartbeat":true,"hours":12}
{"start":true,"hours":12,"heartbeat":true}

Once these requests complete, your Notecard will self-provision with Notehub and start tracking location and movement.

If your application needs to capture and sync additional location-tagged data during tracking, or you wish to control tracking modes and intervals at runtime, you can build a host-controlled tracker. In this scenario, the Notecard receives the same requests as above, with the difference being that these requests are sent from a host MCU and can be adjusted by that host depending on the needs of your application.

When host-controlled, you’ll configure the tracker in firmware after boot, and before entering the application loop. For instance, assume that you’re working with an Arduino-style host that will configure the Notecard as a tracker, and capture environmental readings from a BME680. You’ll start by making a serial connection to the Notecard, and sending each tracker configuration request:

#include <Notecard.h>
#include <Wire.h>
#include <seeed_bme680.h>

#define usbSerial Serial
#define txRxPinsSerial Serial1
#define productUID "com.veritas.delivery-fleet.tracker"

#define IIC_ADDR  uint8_t(0x76)
Seeed_BME680 bmeSensor(IIC_ADDR);

Notecard notecard;

long previousMillis = 0;
long interval = 60000 * 10;

void setup()
{
  usbSerial.begin(115200);

  notecard.setDebugOutputStream(usbSerial);
  notecard.begin();

  J *req = notecard.newRequest("hub.set");
  JAddStringToObject(req, "product", productUID);
  JAddStringToObject(req, "mode", "periodic");
  JAddNumberToObject(req, "outbound", 60);
  JAddNumberToObject(req, "inbound", 720);
  notecard.sendRequest(req);

  req = notecard.newRequest("card.location.mode");
  JAddStringToObject(req, "mode", "periodic");
  JAddNumberToObject(req, "seconds", 3600);
  notecard.sendRequest(req);

  req = notecard.newRequest("card.location.track");
  JAddBoolToObject(req, "sync", true);
  JAddBoolToObject(req, "heartbeat", true);
  JAddNumberToObject(req, "hours", 12);
  notecard.sendRequest(req);

  if (!bmeSensor.init()) {
    usbSerial.println("Could not find a valid BME680 sensor...");
  } else {
    usbSerial.println("BME680 Connected...");
  }
}
note

This sample does not perform a card.restore because doing so would wipe the Notecard on each reset. The full firmware source in GitHub does show an example for performing a restore only when the Device's ProductUID doesn't match the intended ProductUID.

Then, your application loop will capture readings, and add them as location-tagged Notes to the Notecard.

void loop()
{
  unsigned long currentMillis = millis();

  if ((currentMillis - previousMillis > interval) && notecardProductSet) {
    previousMillis = currentMillis;

    if (bmeSensor.read_sensor_data()) {
      usbSerial.println("Failed to obtain a reading...");
    } else {
      J *req = notecard.newRequest("note.add");
      if (req != NULL) {
        JAddStringToObject(req, "file", "sensors.qo");

        J *body = JCreateObject();
        if (body != NULL) {
          JAddNumberToObject(body, "temp", bmeSensor.sensor_result_value.temperature);
          JAddNumberToObject(body, "humidity", bmeSensor.sensor_result_value.humidity);
          JAddNumberToObject(body, "pressure", bmeSensor.sensor_result_value.pressure / 1000.0);
          JAddNumberToObject(body, "gas", bmeSensor.sensor_result_value.gas / 1000.0);
          JAddItemToObject(req, "body", body);
        }

        notecard.sendRequest(req);
      }
    }
  }
}

Once the application firmware has been deployed to your device and tested, you can add a battery to your project and deploy it to your asset.

The host-controlled tracker has the added benefit of allowing you to adjust Notecard tracking settings in response to sensor readings or certain external conditions. For instance, you can change the mode or increase reading interval when the asset is in motion, and decrease it when the asset is idle for a period of time.

To further customize your tracker, you can consult the Advanced Tracker Configuration section below.

note

The complete source for both configuration approaches can be found in the Blues note-tutorials repository .

Once your tracker is deployed and the Notecard is provisioned, it will synchronize tracking data in accordance with the configuration settings you specified. Upon synchronization, you will be able to view your data in Notehub.io. For both types, tracking entries will show up as Notes from the _motion.qo Notefile (or the Notefile name you specified).

list of tracking events in notehub

If you open an individual Note, you can view the Device location and Time Zone under the location tab.

device location and time zone data

In the JSON tab, you can see tracking data like bearing, distance and velocity in the Note body (which appear if the card.location.mode is set to mode:continuous, or mode:periodic and seconds < 300), as well as the location fields, all of which begin with where and are available whenever a GPS location is acquired.

location data in a tracking note

If you’re using a host-controlled tracker and sending sensor readings in a Notefile, each Note is also tagged with the same where fields as tracking Notes.

the same location data in a host-controlled tracker

Once your tracker is deployed and is synching to Notehub, you can use Routes to send tracker data to any third-party service (including your own custom endpoint) for additional processing and visualization. Notehub Routes can be configured to connect to any external service. Routes also give you the ability to send everything from all your Notecards, targeted fleets, or even Notefiles, and to transform event data before you route it to an external service.

For example, if you wanted to create a Route to send only the data you need from a _motion.qo Note to an external service, you could use a JSONata transformation like this:

{
  "location": {
    "where": where,
    "latitude": where_lat,
    "longitude": where_lon,
    "location": where_location,
    "country": where_country,
    "time_zone": where_timezone
  },
  "motion": {
    "bearing": body.bearing,
    "distance": body.distance,
    "seconds": body.seconds,
    "velocity": body.velocity
  },
  "captured_time": when,
  "sync_time": routed
}

JSONata is a powerful data-transformation language built into Notehub, and you can learn more about it in our JSONata 1-2-3 guide and learn about the process of creating third-party Routes in the Route Tutorials.

The Notecard API commands provided above allow you to configure a basic asset tracker with settings applicable to the most common tracking scenarios. However, your scenario may be unique, which is why diving into the Notecard APIs can reveal additional customizations to optimize your trackers.

You can specify how frequently you would like the device to sample its GPS location with the card.location.mode API and its seconds parameter:

{"req":"card.location.mode","mode":"periodic","seconds":5}

When in periodic mode, the Notecard will only attempt to sample its GPS location when the onboard accelerometer has detected motion. You can increase the sensitivity of the accelerometer with the card.motion.mode API and its sensitivity parameter:

{"req":"card.motion.mode","sensitivity":2}

In order to save battery life, the Notecard will only attempt to sync accumulated tracking data on the intervals provided in the outbound parameter of your hub.set request. However, if you would like to attempt to sync data with Notehub immediately, you can set the "sync":true parameter of the card.location.track API:

{"req":"card.location.track","sync":true}

Since asset trackers are often in the field for extended periods of time, it is generally wise to optimize battery consumption. By using the card.voltage API's mode parameter, you can specify the type of battery being used:

{"req":"card.voltage","mode":"lipo"}

The mode value is subsequently used in both the hub.set and card.location.track calls to specify the frequency at which outbound, inbound, and GPS location sampling should occur (i.e. you want the device to make these calls less frequently as battery voltage decreases).

To set the frequency of syncing outbound data with Notehub:

{"req":"hub.set","voutbound":"usb:30;high:60;normal:120;low:240;dead:0","vinbound":"usb:30;high:360;normal:720;low:1440;dead:0"}

To set the frequency of gathering GPS location data:

{"req":"card.location.mode","mode":"periodic","vseconds":"usb:1800;high:3600;normal:7200;low:43200;dead:0"}
note

The Low Power Design guide dives into additional configuration options that can be used to optimize power consumption on the Notecard.

When prototyping an asset tracking solution, it may be useful to gather as much data about the device as possible in the field. To do so, you can set the _log environment variable to all. Note that this will use additional cellular data on your Notecard due to the extensive log data sent to Notehub.

{"req":"env.default","name":"_log","text":"all"}