Send notification from Raspberry pi to Android app - android

I have raspberry pi and an android app. I want to send notifications from the pi to my smartphone app. Is this possible?
The notification needs to be on a individual user basis
Firebase and Google Cloud Messaging seem to be an option.
The pi will act as a server and the android app a client.
The android app does not sent information back.
Again, is the above possible using either Firebase or Google Cloud Messaging.

It actually is possible, you need to setup the server and use the Firebase Admin SDK, see here. You could have a Python server (for example Django), Node.js, Java or Go server. You can have any of these in the Pi.
With the admin SDK you need only to configure it to have the same project ID as the app, then you can send notifications with the SDK, see here.
Note that you'll probably need to save the FCM tokens from the clients in the real time database so you can access them through the Admin SDK and simply direct the messages to them. Or you could have your clients subscribe to a topic and send the notification to the topic, which is much easier than needing to manage tokens.

Related

Is a server required for Firebase Cloud Messaging?

I am currently developing an Android app and I would like to include Firebase Cloud Messaging.
I was planning to have a Raspberry Pi checking a website every 5 Minutes or so and sending push notifications when something changed.
In the official documentation they say that I need an 'app-server' in order to send messages via Firebase.
Does that mean I need to have my Raspi up and running as a server 24/7 and need a static IP / Domain for it?
Or is it enough to have my Raspi send the message via the Api (https://fcm.googleapis.com/fcm/send) as I only need downstream messages?
Any help and explanation would be highly appreciated as I can't find a definite answer in any thread or documentation.
You don't as such need an app-server for just one device. If you have some sort of internet connectivity on your Raspberry Pi device, all you need to do is make a request to the firebase API.
Firebase (Google servers) will handle the rest by pushing notifications to all the registered devices.
Sending downstream messages (messages to devices) requires that you specify the FCM server key. This key allows sending FCM messages on your behalf, so should only be used on environments you trust.
Typically this means a server that you control. But the recently launched Cloud Functions for Firebase can also serve as such a trusted environment. After all: only developers who have access to your Firebase project can access your Cloud Functions code, and those developers can already send messages using the Notification panel in the Firebase console.
Any device you control in your own environment is also fine as a trusted environment. It doesn't have to have a fixed IP address, since the FCM server typically receives its instructions through XMPP or (more commonly these days) through the Firebase Database. Both of these approaches initiate the connections from the trusted device to Google's servers, so can run without accepting incoming connections.
You don't need any server to implement FCM.

Send Firebase Notifications from android device

I just switched my app over to firebase 2.0 from parse. Basically I have an android app (main app) built for the general public to use. Then I also built a second app (manager app) that only I and a few others have access to which is used to update the content of the main app. Now I am adding in notifications which work fine when I send them from the firebase console, however, is it possible to send them from the manager app to the main app? If not, what would I need to do in order to send them from somewhere other than the console (I don't want anyone else to have access to the console but would like them to be able to send notifications.) Thanks!
Seems like you are looking for device to device messaging. This is not currently supported by FCM, so you will need some type of server.
The server could implement XMPP in which case it can be a relay, upstream messages from admin client will be converted to downstream messages to non-admin clients.
The server could watch the Firebase Relatime Database and then the admin client could write something to the database and the server watching the database could then take action and send notifications to non-admin clients.

How do Asp.net backend and Web API web service hosted on Azure send push notification to mobile app?

I am building a mobile app, for both Android and iPhone. I outsourced the mobile end to an app company, while I myself develop the back end and web service part with asp.net and hosted them on Azure. The web service is developed with Web API 2.0, and it is deployed to Azure as a web site. The back-end is developed with asp.net web forms and deployed in to Azure as a web site.
There are 2 cases when a mobile user will receive some messages:
(1) When some mobile users post some messages, other mobile users will receive them.
(2) In the back end, if an administrator publishes a message, all mobile users will receive it.
Currently in my back end and web service, when mobile user post message or an administrator publishes a message, I just update database table to save that message. I thought the mobile end will keep pulling database table and get the latest message - until today. Today the app company told me I need to PUSH those messages to phones. He suggested some third party service to achieve this.
I then checked Azure documents, it seems they have built-in push function in their service so that I don't need go for a third party service. But I am confused, I saw there is "Cloud Services", there is "Mobile Services", and there is "Service Bus-Notification Hub". Which one should I use to make my back end and web service be able to send push notification to mobile devices? How should I modify my existing back end and web service projects in Visual Studio Express 2013? Do I still deploy them to Azure as web sites?
by message, I don't mean SMS, I mean some text data.
Given that you've already invested some reasonable development time in both the Android Application and your back-end services, it sounds like you're looking for Notification Hubs. Notification Hubs are designed specifically for sending push notifications to both individual users and groups of users across one or more mobile platforms.
As suggested in my comment, Cloud Services is a means of hosting your application on Azure (for your purposes it would offer a heavier-weight alternative to Azure Websites with an improved SLA), and Mobile Services provides a set of libraries and APIs to abstract interacting with your application's server-side data.
To use a Notification Hub to send push notifications you'll need to do a few things (described in detail in the linked documentation):
Go to the portal and create yourself a new Notification Hub
Create a Google Cloud Messaging Project via the Google Cloud Console (Azure will use this to transport your message to the relevant Android devices)
Update your back-end service to use Notification Hub to send messages
Modify your android application to use the the associated Azure messaging libraries to receive your push notifications
I hate to link directly to documentation, but the best way to get started with this functionality is via the following tutorial from the Azure documentation:
http://azure.microsoft.com/en-us/documentation/articles/notification-hubs-android-get-started/. This covers the basic changes you'll need to make to both your Android application to handle push notifications, and to your back-end service in order to send them.
You'll still be able to deploy your server-side components to Azure Websites.
Note that sending messages via Notification Hub comes with a price tag, though there is a free tier that limits you to 500 devices and 100,000 push notifications per month, as described in http://azure.microsoft.com/en-us/pricing/details/notification-hubs/.
EDIT: Here's an example of using Notification Hub to send messages to individual users:
http://azure.microsoft.com/en-us/documentation/articles/notification-hubs-aspnet-notify-users/

Is Google Cloud Messaging from Android to Android possible?

I read about Google Cloud Messaging at http://developer.android.com/google/gcm/gcm.html.
It supports Third Party Application server to Android application push notification.
I am wondering whether it is possible to implement the same thing push/receive notification from an Android app on one mobile to the same Android app on another mobile using Google Cloud Messaging.
If not, is there any other free service available similar to Google Cloud Messaging?
An Android device can send a GCM message to another Android device. All it needs is the API Key (of the Google API Project ID that the app uses to register to GCM) an the Registration ID of the other device. Using these parameters it can send a GCM message to another device via an HTTP request.
Usually applications that use GCM require a 3rd party server in order to store the Registration IDs of all registered devices. If your app has a different way to let devices share their Registration IDs with each other without requiring a server, you don't need the server.
As far as I'm aware, there has to be a server in the middle to send the push notifications (Android -> Personal Server -> GCM Server -> Android)
So the Android device sending the notification would send some data to a script on the server (using a HTTP GET/POST), and that script would then send the push notifications to all the devices that you wanted it to
Following the example Code from google (GCM Client Example), you can build an app to get a registration ID for your device, but sending messages without a server wouldn't work in my opinion. I didn't tried by now, but what about using the Google Backend Starter, or (what I tried) using a Backend as a Service Provider like apiOmat if you can't afford or don't want to set up a server.

Instant Messaging on Android with Google Cloud Messaging

I was just looking at the new Google Cloud Messaging (GCM) and I was wondering if it is possible to use GCM for Instant Messaging on your Android application?
I saw you can send data, like a message, from a server, but is it also possible to send from one device to another one?
And how would this work?
Some example code would be really helpful..
Tnx!
The official docs on Google Cloud Messaging for Android does mention that GCM can be used to develop an instant messaging app.
...or it could be a message containing up to 4kb of payload data (so
apps like instant messaging can consume the message directly).
So we went ahead and created an instant messaging app using GCM. The server-side is powered by Google App Engine. You can read the complete tutorial here. Create an Instant Messaging app using Google Cloud Messaging (GCM)
So it is possible to use GCM for Instant Messaging on Android, to answer your question. However, reliability of GCM compared to XMPP for IM is another topic.
Just my two cents:
I think you should not use GCM for delivering IM. You should have a dedicated server where your Android IM apps will connect to, using a persistent socket connection. Your server will know who is online or not and therefore can present an 'online list' to all the apps.
GCM can come into play, while users are offline or not running your app. A GCM message can be sent to them to indicate 'XXXX wants to chat'. They can then launch your app and automatically connects to a chat session.
Google has said that the delivery of GCM messages are not guaranteed. This reason alone is not a good idea to rely on them for Instant Messaging.
Try pub nub - it is pretty easy to implement - send Im from one mobile to another - simply fire up the web page (see link) in the browser , and chat between pc, mobile - and works - with 'no server'. Code is for javascript but they also have java. Chat app using jquerymobile web app framework
You might want to check out how a server sends a message to the GCM Service. It is possible to use php on Server side so it should be possible to adapt that to a POST request directly out of your application. However, to communicate you need the registered ids of the devices you want to send data to. Means you will need something to store and get them. Best solution would be your own (web) server which stores all ids and handles the Message sending.

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