Cloud functions for tailored vehicle telematics solutions – with examples

Using Cloud Functions for remote GPS tracker management (Python example with Vonage SMS)

There's a frequent need for remote management of vehicles, particularly for preventing unauthorized use during off-hours or outside designated geozones. A typical scenario involves sending SMS commands to GPS trackers to disable the engine. Let’s explore a straightforward example where a cloud function responds to an external trigger from Navixy, such as MQTT or Webhook, by sending a predefined SMS command to the vehicle.

We'll guide you through setting up a simple Google Cloud Function using Python, with the aim of sending an SMS command to a GPS tracker. We'll use Vonage, a messaging service, for the SMS functionality.

Accessing the Cloud Functions interface

To access the Google Cloud Console, open your web browser and navigate to console.cloud.google.com. Once there, log in using your Google account. If you don’t already have a Google Cloud account, you’ll need to create one by signing up.

Once you're logged in, to navigate to Cloud Functions, locate the navigation menu on the left side of the console:

• Click on "Cloud Functions" under the "Compute" section. If it's not immediately visible, you may find it under the "More products" section or use the search bar at the top.
• This will open the Cloud Functions interface where you can create and manage your cloud functions.

In this interface, you'll write and deploy the code described earlier, managing the functions you create for various purposes, such as sending SMS commands to GPS trackers.

Setting up the environment

Start with installing the necessary packages in your requirements.txt file. This includes functions-framework for creating Google Cloud Functions and vonage for sending SMS.

requirements.txt:

functions-framework==3.*
requests
vonage

Writing the function

To create the SMS command function, you'll need to write the following code in main.py:

• In main.py, import the necessary libraries.
• Set up a function send_sms_command which will be triggered via an HTTP request.
• Use environment variables for sensitive information like Vonage API keys and phone numbers. This ensures security and flexibility.
• The function constructs an SMS message and sends it using Vonage’s services.
• Handle responses and errors to confirm the message status.

main.py:

import functions_framework
import vonage
import os

@functions_framework.http
def send_sms_command(request):
   # Use environment variables for sensitive information
   client = vonage.Client(key=os.environ.get("VONAGE_API_KEY"), secret=os.environ.get("VONAGE_API_SECRET"))
   sms = vonage.Sms(client)

   # Environment variables for phone numbers and text
   vonage_number = os.environ.get("VONAGE_NUMBER")  # Your Vonage number
   recipient_number = os.environ.get("RECIPIENT_NUMBER")  # Recipient's phone number
   text_message = os.environ.get("TEXT_MESSAGE", "Default command")  # Text message, with a default

   try:
       responseData = sms.send_message({
           "from": vonage_number,
           "to": recipient_number,
           "text": text_message,
       })

       if responseData["messages"][0]["status"] == "0":
           print("Message sent successfully.")
           return 'Message sent successfully.', 200
       else:
           error_text = responseData['messages'][0].get('error-text', 'Unknown error')
           print(f"Message failed with error: {error_text}")
           return f"Message failed with error: {error_text}", 500
   except Exception as e:
       print(f"An error occurred: {e}")
       return f"An error occurred: {e}", 500

To verify the functionality of your Google Cloud Function with two different phone numbers, use the following curl command:

curl -X POST https://us-central1-dn-sandbox-376818.cloudfunctions.net/send-sms-command \
-H "Content-Type: application/json" \
-d '{"recipients": ["Number1", "Number2"]}'

In this command, replace the url with the url pointing to your function, Number1 and Number2 with the actual phone numbers of the SIM cards installed in the GPS devices (for example, 18189399214). This test will ensure that the function is correctly sending SMS commands to the specified numbers.

The path forward with Cloud Functions and Navixy

As we've explored in this post, the integration of cloud-based functionalities like Google Cloud Functions with Navixy's platform opens up a world of efficiency and customization. From complex data processing in heavy machinery to simple SMS commands for remote vehicle immobilization, the versatility of these solutions is evident. They cater not just to advanced requirements but also offer an accessible starting point for those new to cloud integrations.

Navixy is committed to supporting developers in the telematics field with a flexible toolkit that goes beyond just providing IoT data. Our focus is on enabling you to build innovative, tailored solutions that address specific business needs. We encourage you to start building your solutions and invite you to contact our solution engineers for assistance with your projects. We are ready to help you harness the full potential of cloud functions in conjunction with our robust telematics platform, ensuring your success in this dynamic technological landscape.