sigfox-gcloud is a software framework for building a Sigfox server with Google Cloud Functions and Google Cloud PubSub message queues:

• Modular: Process Sigfox messages in modular steps using simple Node.js (JavaScript) functions.

• Extensible: Allows new Sigfox message processing modules to be added on the fly without disrupting or restarting all modules.

• Robust: The processing modules are implemented as separate Google Cloud Functions, so one module crashing will not affect others. Google Cloud PubSub message queues are used to pass the Sigfox messages reliably between processing modules.

Read about the architecture here: How To Build Your Sigfox Server

Other sigfox-cloud modules available:

1. sigfox-gcloud-ubidots: Adapter for integrating Sigfox devices with the easy and friendly Ubidots IoT platform

2. sigfox-gcloud-data: Adapter for writing Sigfox messages into SQL databases like MySQL, Postgres, MSSQL, MariaDB and Oracle

Releases

• Version 1.0.0 (11 Oct 2017): Supports Google Cloud Trace for tracing the Sigfox Callback processing time across Cloud Functions. Supports Google Cloud Debug for capturing Node.js memory snapshots. Supports Ubidots map visualisation of Sigfox Geolocation and other geolocated sensor data points.

Getting Started

For development we support Linux, MacOS and Ubuntu on Windows 10. Open a command prompt and enter these commands to download the sigfox-cloud source folder to your computer.

git clone https://github.com/UnaBiz/sigfox-gcloud.git
cd sigfox-gcloud

If you're using Ubuntu on Windows 10, we recommend that you launch "Bash on Ubuntu on Windows" and enter the following commands to download the source files into the folder /mnt/c/sigfox-gcloud:

cd /mnt/c
git clone https://github.com/UnaBiz/sigfox-gcloud.git
cd sigfox-gcloud

That's because /mnt/c/sigfox-gcloud under bash is a shortcut to c:\sigfox-gcloud under Windows.
So you could use Windows Explorer and other Windows tools to browse and edit files in the folder. Remember to use a text editor like Visual Studio Code that can save files using the Linux line-ending convention (linefeed only: \n), instead of the Windows convention (carriage return + linefeed: \r \n).

Setting up Google Cloud

1. Create a Google Cloud Platform project. Assume the project ID is myproject.

   GO TO THE PROJECTS PAGE

2. Open a bash command prompt. For Windows, open "Bash on Ubuntu on Windows."
   Create a file named .env in the sigfox-gcloud folder
   and populate the GCLOUD_PROJECT variable with your project ID. To do that, you may use this command (change myproject to your project ID):

   echo GCLOUD_PROJECT=myproject >.env

3. Enable billing for your project.

   ENABLE BILLING

4. Click this special link to enable the Cloud Functions, Cloud Pub/Sub, Compute Engine, Stackdriver Logging APIs for your project.

   ENABLE THE APIS

5. For Linux and MacOS, click this link to install and initialize the Google Cloud SDK.

   GOOGLE CLOUD SDK

   For Ubuntu on Windows 10, open "Bash on Ubuntu on Windows" and follow the Ubuntu installation steps here:

   https://cloud.google.com/sdk/downloads#apt-get

6. Update and install gcloud components:

   gcloud components update
   gcloud components install beta

7. Switch to the project you have created: (change myproject to your project ID)

   gcloud config set project myproject
   gcloud config list project

   Your project ID should be displayed after list project.

8. Add the following sigfox-route setting to the Google Cloud Project Metadata store. This route says that all received Sigfox messages will be processed by the two steps decodeStructuredMessage and logToGoogleSheets.

   gcloud compute project-info add-metadata --metadata=^:^sigfox-route=decodeStructuredMessage,logToGoogleSheets

9. Create the Google PubSub message queues that we will use to route the Sigfox messages between the Cloud Functions:

   gcloud beta pubsub topics create sigfox.devices.all
   gcloud beta pubsub topics create sigfox.types.decodeStructuredMessage
   gcloud beta pubsub topics create sigfox.types.logToGoogleSheets

   Optional: We may create the PubSub message queues for each device ID and device type that we wish to support. For example, to support device ID 1A234 and device type gps, we would execute:

   # Optional...
   gcloud beta pubsub topics create sigfox.devices.1A234
   gcloud beta pubsub topics create sigfox.types.gps

   The PubSub queues will be used as follows:

   • sigfox.devices.all: The queue that will receive Sigfox messages for all devices

   • sigfox.devices.<deviceID>: The queue that will receive Sigfox messages for a specific device e.g. sigfox.devices.1A234. Device ID must be in uppercase.

   • sigfox.types.<deviceType>: The queue that will receive Sigfox messages for a specific device type or a message processing step e.g. sigfox.types.gps

   • sigfox.types.decodeStructuredMessage, sigfox.types.logToGoogleSheets: used for sending messages to be decoded and logged in the Sigfox message processing demo below

10. If you plan to run the Google Sheets demo below:

    • Go to the Google Cloud IAM to create a Google Cloud Service Account. Download the JSON credentials into google-credentials.json in the sigfox-gcloud folder.

    • Go to the Google Cloud IAM and ensure the Google Cloud Service Account in google-credentials.json has been granted Editor rights to your Google Cloud Project

11. Create a Google Cloud Storage bucket gs://<projectid>-sigfox-gcloud to stage our Cloud Functions files during deployment, like this: (change myproject to your project ID)

    gsutil mb gs://myproject-sigfox-gcloud

12. Deploy all the included Cloud Functions (including the demo functions) with the deployall.sh script:

    chmod +x */*.sh
    scripts/deployall.sh

13. Go to the Google Cloud Functions Console

    There should 4 Cloud Functions defined Click the sigfoxCallback Cloud Function

14. Click the Trigger tab Copy the URL for sigfoxCallback The URL should look like:
    https://us-central1-myproject.cloudfunctions.net/sigfoxCallback

    This is the HTTPS URL that will invoke the sigfoxCallback Cloud Function. We shall set this as the Sigfox callback URL later.

Setting the Sigfox callback

1. As a Sigfox device maker you should have access to the Sigfox Backend Portal. We shall use the portal to configure the callback URL for your device.

   If you're not a Sigfox device maker yet, you may purchase the UnaShield Sigfox Shield for Arduino to get access to the Sigfox Backend.

   https://github.com/UnaBiz/unabiz-arduino/wiki/UnaShield

2. Log on to the Sigfox Backend Portal Click "Device Type" Click the Device Type that you wish to connect to Google Cloud

3. Click "Callbacks"

4. Click "New"

5. When prompted to select the callback type, select Custom Callback

6. Fill in the callback details as follows:

   • Type: DATA, BIDIR

   • Channel: URL

   • Send duplicate: Unchecked (No)

   • Custom payload config: (Blank)

   • URL Pattern: Enter the Sigfox Callback URL that we have copied earlier. It should look like:
     https://us-central1-myproject.cloudfunctions.net/sigfoxCallback

   • Use HTTP Method: POST

   • Send SNI: Checked (Yes)

   • Headers: (Blank)

   • Content Type: application/json

   • Set the Body (Sigfox message payload) as:

     {                             
      "device" : "{device}",        
      "data" : "{data}",            
      "time" : "{time}",            
      "duplicate": "{duplicate}",   
      "snr": "{snr}",               
      "station": "{station}",       
      "avgSnr": "{avgSnr}",         
      "lat": "{lat}",               
      "lng": "{lng}",               
      "rssi": "{rssi}",             
      "seqNumber": "{seqNumber}",   
      "ack": "{ack}",               
      "longPolling": "{longPolling}"
     }                             

     With this setting, the Sigfox cloud will deliver messages to our server in JSON format like this:

     {
       "device":"1A2345",
       "data":"920e82002731b01db0512201",
       "time":"1476980426",
       "duplicate":"false",
       "snr":"18.86",
       "station":"1234",
       "avgSnr":"15.54",
       "lat":"1",
       "lng":"104",
       "rssi":"-123.00",
       "seqNumber":"1492",
       "ack":"false",
       "longPolling":"false"
     }

   • Optional: We may set the callback type in the sigfoxCallback URL by passing the type parameter in the URL like this:

     https://us-central1-myproject.cloudfunctions.net/sigfoxCallback?type=gps

     It's OK to omit the type parameter, we may also use routing rules to define the processing steps.

Optional: Configuring Sigfox downlink

Optional: The sigfox-gcloud server can be used to return downlink data to the Sigfox device after processing a callback from the Sigfox cloud. If we plan to use the downlink capability, there are two additional things to configure:

1. In the Device Type settings, set the Downlink Mode to Callback

2. In the Callbacks list under Device Type, there is a hollow circle in the Downlink column.
   Click the circle and change it to a filled purple circle

3. The message handling code in sigfoxCallback is presently hardcoded to return 0123456789abcdef. This may be changed if necessary.

   https://github.com/UnaBiz/sigfox-gcloud/blob/master/sigfoxCallback/index.js

   function getResponse(req, device0, body /* , msg */) {
     //  Compose the callback response to Sigfox Cloud and return as a promise.
     //  If body.ack is true, then we must wait for the result and return to Sigfox as the downlink data.
     //  Else tell Sigfox we will not be returning any downlink data.
   ...
     //  Wait for the result.  Must be 8 bytes hex.
     //  TODO: We hardcode the result for now.
     const result = '0123456789abcdef';

4. To write a program for the UnaShield Sigfox Shield to send a downlink request, refer to https://github.com/UnaBiz/unabiz-arduino/wiki/Downlink

Optional: Defining the Sigfox message processing steps

1. We define the Sigfox message processing steps as a route in the Google Cloud Common Instance Metadata Store. This metadata store is a key-value store that's shared by all programs running in the same Google Cloud project.

   You may inspect and update the route through the Google Cloud Compute Engine Metadata Editor. Look for the key named sigfox-route.

2. A route looks like

   decodeStructuredMessage, logToGoogleSheets, ...

   in which decodeStructuredMessage and logToGoogleSheets are the Google Cloud Functions to be called sequentially. These Cloud Functions will subscribe to the following Google PubSub queues to listen for Sigfox messages:

   sigfox.types.decodeStructuredMessage
   sigfox.types.logToGoogleSheets

3. Here is an example of a route for Sigfox message processing, as shown in the demo.

   Sigfox Cloud

   → sigfoxCallback cloud function to ingest messages from Sigfox Cloud

   → sigfox.devices.all message queue

   → routeMessage cloud function to route the message

   → sigfox.types.decodeStructuredMessage message queue

   → decodeStructuredMessage cloud function to decode the structured sensor data in the message

   → sigfox.types.logToGoogleSheets message queue

   → logToGoogleSheets cloud function to write the decoded message to Google Sheets

4. How it works:

   • Sigfox messages are pushed by the Sigfox Cloud to the Google Cloud Function sigfoxCallback

   • Cloud Function sigfoxCallback delivers the message to PubSub message queue sigfox.devices.all, as well as to the device ID and device type queues

   • Cloud Function routeMessage listens to PubSub message queue sigfox.devices.all and picks up the new message

   • Cloud Function routeMessage assigns a route to the Sigfox message by reading the sigfox-route from the Google Compute Metadata Store. The route looks like this:

     decodeStructuredMessage, logToGoogleSheets

   • This route sends the message to functions decodeStructuredMessage and logToGoogleSheets via the queues sigfox.types.decodeStructuredMessage and sigfox.types.logToGoogleSheets

5. See this for the definition of structured messages:

   https://github.com/UnaBiz/unabiz-arduino/wiki/UnaShield

6. Also read about the architecture here: How To Build Your Sigfox Server

Viewing sigfox-gcloud server logs

You may view the logs through the Google Cloud Logging Console
Select "Cloud Function" as the "Resource"

From the screen above you can see the logs generated as each Sigfox message is processed in stages by sigfox-gcloud:

• Sigfox Device IDs are shown in square brackets e.g. [ 2C30EB ]

• Completed Steps are denoted by _<<_

• sigfoxCallback is the Google Cloud Function that listens for incoming HTTPS messages delivered by Sigfox

• routeMessage passes the Sigfox message to various Google Cloud Functions to decode and process the message

• decodeStructuredMessage decodes a compressed Sigfox message that contains multiple field names and field values

• sendToUbidots is a Google Cloud Function that sends the decoded sensor data to Ubidots via the Ubidots API. See sigfox-gcloud-ubidots

Tracing sigfox-gcloud server performance

The Google Cloud Trace Console shows you the time taken by each step of the Sigfox message processing pipeline, tracing the message through every Google Cloud Function.

Each message delivered by Sigfox appears as a separate trace timeline. Messages are shown like 2C30EB seq:1913 where 2C30EB is the Sigfox Device ID and 1913 is the Sigfox Message Sequence Number (seqNumber)

The Google Stackdriver Trace API needs to be enabled manually.

Custom reports may be created in Google Cloud Trace Control to benchmark the performance of each processing step over time.

Understanding and troubleshooting the sigfox-gcloud server

To understand each processing step in the sigfox-gcloud server, you may use the Google Cloud Debug Console to set breakpoints and capture in-memory variable values for each Google Cloud Function, without stopping or reconfiguring the server.

In the example below, we have set a breakpoint in the sigfoxCallback Google Cloud Function. The captured in-memory values are displayed at right - you can see the Sigfox message that was received by the callback. The Callback Stack appears at the lower right.

Google Cloud Debug is also useful for troubleshooting your custom message processing code without having to insert the debugging code yourself.

Testing the sigfox-gcloud server

1. Send some Sigfox messages from the Sigfox devices. Monitor the progress of the processing through the Google Cloud Logging Console.
   Select "Cloud Function" as the "Resource"

2. Processing errors will be reported to the Google Cloud Error Reporting Console.

3. The Google Cloud PubSub Console shows the message queues that have been created and how many Cloud Functions are listening to each queue.

4. We may configure Google Cloud Stackdriver Monitoring to create incident reports upon detecting any errors. Stackdriver may also be used to generate dashboards for monitoring the PubSub message processing queues.

5. To check whether the downlink was sent successfully from the server to the device, check the Sigfox Backend. Go to the Device page, click Messages and click the down-arrow circle in the Callbacks column. It should show status "Acked"

6. If the status is "Pending", the Sigfox network is still attempting to push the downlink message to the device.

Demo

1. The sample code calls the decodeStructuredMessage Cloud Function to decode a structured Sigfox message containing encoded sensor data (counter, light level, temperature). Then it calls the logToGoogleSheets Cloud Function to display the decoded Sigfox messages in a Google Sheets spreadsheet in real time.

   See this for the definition of structured messages:

   https://github.com/UnaBiz/unabiz-arduino/wiki/UnaShield

2. Ensure that the Google Service Account in google-credentials.json has been granted these permission scopes for Sheets API, Drive API:

   https://www.googleapis.com/auth/spreadsheets
   https://www.googleapis.com/auth/drive

3. Create a folder in Google Drive and grant write access to the email address specified in google-credentials.json.

4. In that folder, create a Google Sheets spreadsheet with the device ID (in uppercase) as the filename, e.g. 1A2345. Omit any file extensions like .xls

5. In the spreadsheet, rename the first tab / worksheet as Log.

6. Populate the first row with these column headers, one name per column:

   timestamp+8
   data
   ctr
   lig
   tmp
   seqNumberCheck
   rssi
   duplicate
   snr
   station
   avgSnr
   lat
   lng
   ack
   longPolling
   time
   seqNumber
   type
   device

7. Change timestamp+8 to indicate your time zone, e.g. for UTC+10 change it to timestamp+10

8. Refer to the sample Google Sheet here:

   https://docs.google.com/spreadsheets/d/1OtlfVx6kibMxnZoSwq76Vod8HhaK5tzBIBAewtZlbXM/edit?usp=sharing

9. To test the structured message decoding, send a Sigfox message from your Sigfox device with the data field set to:

   920e82002731b01db0512201

   We may also use a URL testing tool like Postman to send a POST request to the sigfoxCallback URL e.g.

   https://us-central1-myproject.cloudfunctions.net/sigfoxCallback

   Set the Content-Type header to application/json. If you're using Postman, click Body -> Raw -> JSON (application/json) Set the body to:

   {
     "device":"1A2345",
     "data":"920e82002731b01db0512201",
     "time":"1476980426",
     "duplicate":"false",
     "snr":"18.86",
     "station":"0000",
     "avgSnr":"15.54",
     "lat":"1",
     "lng":"104",
     "rssi":"-123.00",
     "seqNumber":"1492",
     "ack":"false",
     "longPolling":"false"
   }

   where device is your device ID.

   Here's the request in Postman:

   We may use the curl command as well. Remember to change myproject and 1A2345 to your project ID and device ID.

   curl --request POST \
     --url https://us-central1-myproject.cloudfunctions.net/sigfoxCallback \
     --header 'cache-control: no-cache' \
     --header 'content-type: application/json' \
     --data '{"device":"1A2345", "data":"920e82002731b01db0512201", "time":"1476980426", "duplicate":"false", "snr":"18.86", "station":"0000", "avgSnr":"15.54", "lat":"1", "lng":"104", "rssi":"-123.00", "seqNumber":"1492", "ack":"false", "longPolling":"false"}'

10. The response from the callback function should look like this:

    {
      "1A2345": {
        "noData": true
      }
    }

11. The test message sent above will be decoded and displayed in the Google Sheet as

    ctr (counter): 13
    lig (light level): 760
    tmp (temperature): 29        

Creating a Sigfox message processing module

1. Create a Google Cloud Function, using decodeStructuredMessage as a template:

   mkdir myfunction
   cp decodeStructuredMessage/index.js myfunction
   cp decodeStructuredMessage/package.json myfunction
   cp decodeStructuredMessage/deploy.sh myfunction
   cd myfunction

2. Install sigfox-gcloud library:

   npm install --save sigfox-gcloud

3. Edit the Cloud Function deployment script
   deploy.sh. Edit the name parameter and replace the value by the name of your message processing function, e.g. myfunction.

   Any message delivered to the queue sigfox.types.myfunction will trigger the message processing function.

   name=myfunction
   trigger=--trigger-topic
   topic=sigfox.types.${name}

4. Create the listen queue in Google PubSub Console, e.g. sigfox.types.myfunction

   Or run this command (change myfunction to the function name):

   gcloud beta pubsub topics create sigfox.types.myfunction

5. Edit the message processing code in index.js.
   Every message processing function has 3 sections:

   • Common Declarations

     if (process.env.FUNCTION_NAME) {
       require('@google-cloud/trace-agent').start();
       require('@google-cloud/debug-agent').start();
     }
     const sgcloud = require('sigfox-gcloud');

     The standard declarations here initialise the sigfox-gcloud library, Google Cloud Trace and Google Cloud Debug functions. Retain this section without changes.

   • Message Processing Code

     Replace this section with our JavaScript message processing code. We need to expose a function named task() that will perform the processing for a Sigfox message that has been delivered.

     function task(req, device, body, msg)

     req contains info about the message that triggered the task

     device is the Sigfox device ID

     body is the body of the Sigfox message, which contains fields like:

     {
       "device":"1A2345",
       "data":"920e82002731b01db0512201",
       "time":"1476980426",
       "duplicate":"false",
       "snr":"18.86",
       "station":"0000",
       "avgSnr":"15.54",
       "lat":"1",
       "lng":"104",
       "rssi":"-123.00",
       "seqNumber":"1492",
       "ack":"false",
       "longPolling":"false"
     }

     msg contains the complete message delivered by Google Cloud PubSub. This includes the device, body, history and route fields.

     task() should return a promise for the updated message after processing the message.

     To write debug messages to the Google Cloud Logging Console, call sgcloud.log(req, action, parameters) like this:

      sgcloud.log(req, 'decodeMessage', { result, body });

     To report errors to the Google Cloud Error Reporting Console, call sgcloud.log(req, action, parameters), where parameters includes an error field containing the JavaScript error.

       sgcloud.log(req, 'decodeMessage', { error, body });
       

   • Main Function

     exports.main = event => sgcloud.main(event, task);

     The main() function that will be called upon receiving a message shall always be defined as above. This calls the main() function in the sigfox-gcloud library which performs the following:

     • Decode the message received from Google Cloud PubSub (base64 format)

     • Execute the task() function above to process the message

     • Record the history of task() functions called

     • Dispatch the resulting message to the next step (if any) of the message route contained in the message. The message route was set previously by the routeMessage cloud function.

6. Deploy the module. This creates/updates the Google Cloud Function and listens to the PubSub queue for new messages to be processed by the function.

   ./deploy.sh

7. Update the Sigfox message processing route sigfox-route in Google Cloud Compute Engine Metadata Editor. Add the new processing step to the list of steps:

   decodeStructuredMessage, logToGoogleSheets

   The new route will take effect in 10 seconds when the route cache is refreshed.

8. To test, send a Sigfox message from your Sigfox device.

sigfox-gcloud-ubidots adapter for Ubidots

The sigfox-gcloud-ubidots adapter is a Google Cloud Function (developed with the sigfox-gcloud framework) that integrates with Ubidots to provide a comprehensive IoT platform for Sigfox.

With Ubidots and sigfox-gcloud-ubidots, you may easily visualise sensor data from your Sigfox devices and monitor for alerts. To perform custom processing of your Sigfox device messages before passing to Ubidots, you may write a Google Cloud Function with the sigfox-gcloud framework.

sigfox-gcloud-ubidots also lets you to visualise in real-time the Sigfox Geolocation data from your Sigfox devices, or other kinds of GPS tracking data. For details, check out:

https://www.npmjs.com/package/sigfox-gcloud-ubidots

https://unabiz.github.io/unashield/ubidots

sigfox-gcloud-data adapter for databases

The sigfox-gcloud-data adapter is a Google Cloud Function (developed with the sigfox-gcloud framework) that writes decoded Sigfox messages into many types of SQL databases including MySQL, Postgres, MSSQL, MariaDB and Oracle. For details, check out:

https://www.npmjs.com/package/sigfox-gcloud-data