Say I have 1000 IoT devices. Each device sends telemetry data to the Azure cloud each second. There is mobile app which displays that telemetry data. Mobile user can see data from specific IoT device only, based on his login. It's not an issue to receive all those d2c messages in the cloud, for example with Event Hubs (initially i wanted to use IoT Hub, but it's pretty expensive with huge amount of messages). It's also clear how to get general event stream (for example, by listening to events endpoint in IoT hub). However, this stream gives all messages, from all devices. Receiving all messages in mobile app and filtering them there does not look like right choice. How can I subscribe to events from specific IoT device only? Can I do this with Event Hubs and/or IoT Hub only, or do I need to utilize other Azure services? If yes, what will be the most cheap solution.
Update:
Original question was just about Azure. But is it possible to achieve what I need with AWS without requiring adding multiple parts to the system. Is Message Broker for AWS IoT what I need here (as I understood, this is built in functionality of AWS IoT Core)?
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I have developed a device that is able to connect to Google IoT Core through the MQTT protocol, I can publish MQTT messages on telemetry topics (/devices/DEVICE_ID/events).
But I can't figure out how to subscribe my device to a generic topic and send messages from cloud to device via this topic.
Through the console I created the topic MyTestTopic and a subscription MyTestTopic-sub, I guess that somehow I have to subscribe my device to the subscription MyTestTopic-sub, but I don't know to which topic I have to subscribe my device.
I tried to subscribe my device to the following topics:
projects/PROJECT_ID/topics/MyTestTopic
projects/PROJECT_ID/topics/MyTestTopic-sub
/devices/DEVICE_ID/events/MyTestTopic
/devices/DEVICE_ID/events/MyTestTopic-sub
the subscription to these topics seems to be successful, but the device does not receive the messages I send from the console.
Any suggestions please?
I found this thread (Google Cloud IoT - Invalid MQTT publish topic) from 4 years ago, from which I understand that it is possible to subscribe only to some predefined topics, also from the various documents I have read I understand that Google IoT Core allows devices to subscribe to only two topics: /devices/{device-id}/config and /devices/{device-id}/commands/#
Has anything changed since then?
So to be clear, there are two different "topics" in play here. There's the MQTT topics that are described in the docs you found, config and commands. Those are subscribed to on the device using an MQTT client (e.g. Paho MQTT), and sent down to the device from somewhere else via the IoT Core Admin APIs. Then there's Pub/Sub topics. Out of the box, a device using IoT Core does not directly interact with Pub/Sub at all. They publish/receive via the MQTT topics only. So if you register a device with IoT Core, all messages come and go via the MQTT bridge (or HTTPS).
What Gambit support linked to in that github repo is a direct subscription to a Pub/Sub topic (not MQTT). If you look at the Python code, it's establishing proper Google Cloud Credentials via a json token (service account bearer token) that needs to be present on the device or a proxy device. Depending on the device you're using, that may not be possible of course (implementing GCP APIs on a microcontroller is difficult at best).
The easiest way I've seen this done is to implement a Cloud Function that subscribes to a Pub/Sub topic you want to use, and it implements the proper IoT Core Admin calls to push the Pub/Sub messages down to the device as needed. But of course, it all depends on what you're trying to do.
In my project multiple IoT devices need to publish to a single topic and cloud functions listening to that topic need to process data published by IoT devices. Multiple devices should be able to publish at the same time.A MQTT broker logic is needed. But in Google IoT Core "The MQTT bridge allows only a single connection for a given device ID. If a second device connects with the ID of a device that is already connected, the older device connection will be closed automatically.".
I am new to google cloud IoT and trying to understand basic concepts. I have looked into gateways but I am not sure that gateways work as broker. Can multiple devices publish through a gateway to a same single topic? or should I implement/add a MQTT broker(mosquitto I guess) myself or is there an another way to use google Cloud IoT in my case? Could you guys direct me to the right direction. Opening sub/pub topics for each device doesn't sound right because in my project there can be thousands of IoT devices.
Let all the devices in the registry publish messages to the common topic given to the registry.Then trigger a cloud function with this topic.
You can process the messages with cloud function based on the deviceId
I am working on a project wherein a mobile app (Flutter app) should create a unique identity (IOT thing) of my IOT device machine (on AWS) as soon as the user logins onto the app and also it should establish a connection (and subsequent communications) with the isolated IOT device after its configuration (Somewhat similar to Google Home configuration process).
The process starts with user logging onto the app (using AWS Amplify/Congnito to automatically add the user account in the cloud). Subsequently, the app needs to configure the IOT device (ESP32) and send Wifi credentials of home network by connecting to ESP's WiFi AP. However, since both the app and IOT device are isolated from each other (except during the configuration process), I don't have much idea on how exactly will mobile app connect (creating a unique IOT thing automatically) and communicate with the isolated IOT device over AWS IOT cloud.
I have worked with some of the AWS services like AWS Lambda, DynamoDB, AWS IOT for quite a while, hence I am aware of the basics. One of the possible solutions for the above maybe Fleet Provisioning by a Trusted User feature provided by AWS IOT (I did read it's documentation, but still confused). We can also use ESP32's Bluetooth feature for the app to scan nearby devices with which it needs to connect with, but I am not sure how will the connection establish through AWS cloud.
Since I am a beginner to AWS cloud services, it'd be great if someone can provide a possible solution for the above in detail. Also if possible, please provide a solution which would work incase of a large-scale deployment of the above project.
The parts you may be missing are missing are 1) MQTT messaging, which is the IoT message broker service provided by IoT Core, and 2) the need for an application program interface to handle creating and activating devices.
MQTT is a lightweight and widely adopted messaging protocol that is designed for constrained devices.
Your devices (things) will need to communicate back to AWS via MQTT messages, which are captured and processed by the IoT Rules service.
These rules typically trigger Lambda functions, which implement the process logic you need for your application.
See https://mqtt.org/ and https://docs.aws.amazon.com/iot/latest/developerguide/what-is-aws-iot.html
2} you will want to implement a simple API to handle device activation. The AWS API Gateway service makes it easy to implement APIs. For example, you can implement an endpoint for POST /device/ to create a device. That endpoint can trigger a Lambda handles device provisionsing.
AFAIK, one key difference between the two is that Appsync is implemented using MQTT and has an emphasis on real-time notification, while SNS is more like a general pub/sub service.
The real-time notification part of Appsync seems to be the right tool for a chat application. However with Appsync, I will not be able to push the notification to users if a connection is not established(?)
I would like to have real-time notification for users regardless the application is opened or not. What is the right tool for this purpose?
Generally, you'll probably have a more "ready-to-use" solution for chat using AppSync, e.g. https://aws.amazon.com/blogs/mobile/building-a-serverless-real-time-chat-application-with-aws-appsync/
Using SNS will probably provide more flexibility at the cost of more of your time wiring up custom code.
You are correct that AppSync doesn't natively support push notifications for background applications; for that, you'd need to wire in something like SNS. You could probably couple AppSync with SNS using an AppSync Lambda resolver.
Depending on your requirements, i.e. if it's not essential that a system notification appears for new messages, you can also query AppSync at app startup time for chat messages that were received while the client was disconnected.
I have developed an electronic device that connects to AWS IoT Core service through MQTT protocol. Now I can connect, publish and subscribe topics.
The device has some inputs (i.e. buttons) and outputs (i.e. relays).
Now I want to develop a mobile or web application to let an authorized user read inputs status and read/write outputs. More than one user could be authorized to control a single device.
What it's not clear to me, but I have no knowledge of backend technologies, is how to manage users, i.e. mobile/web app.
One strategy is to create a new Thing for each User, with its own certificate. The web/mobile app uses MQTT protocol as the electronic device. Topics can be used as a chat channel: the user asks for inputs status and the device answers with updated status.
Another strategy could be to create a HTTP API (maybe with AWS Gateway API) that web/mobile apps use. The API is programmed to publish and subscribe topics. The user should have a IAM access.
I know I could user Device Shadow, but I don't think it's a good soltion in my use case. The status of inputs can change frequently (maybe 1000 times a day), but the user wants to retrieve the status through the mobile/web app only sometimes (one a day or less frequently). It's seems it's useless to send so many messages to keep the shadow updated.
you can use to connect your WebApp with AWS IoT via MQTT(publish and subscribe methods are also available in the system).
Front end library documentation
Please Refer the link and see if this solves your problem https://medium.com/#serverlessguru/serverless-real-time-reactjs-app-aws-iot-mqtt-17d023954045.