So the title sounds stupid. I'm not really sure how to really word it, but I want someone to help guide me on what to look for. Little back story first so I'm working on a Raspberry Pi project that involves using an LTE service currently I have a dashboard running on a AWS EC2 web server with a simple user working user login.
I have a raspberry pi that is directly pointed to the dashboard/account via an IP address. I want to know how to do something like giving a device an ID and having it connect to an account. So for example with Nest products you have the QR code on the camera you take a photo and that devices get applied to your account.
Is this even possible with Raspberry Pi(I'm sure anything possible, but is it feasible? If so what should I look into or learn how to do such thing. I know its not something that can be answered in a short paragraph just looking for some guidance.
Right, thanks. Well, I think you need to program this into the pi server app. So currently your Pi is reading a sensor and sending this data to the web server, right? I suppose you have a daemon running, taking readings, and doing an API REST call to the server backend, correct? So what you want is to have a unique code for each pi, sent with the API call, and then on your DB server side,you store all readings related to their unique code.
You don't need to pre-validate this code, there are GUID generators that will create a number for you, guaranteed to be unique for all eternity, so on the PI, you set it up once, to create the PI's code, and use it from then on. Now, server side, then associating a device with a user is a matter of choosing the data associated with a given gui. And I think that covers it.
You can improve on this basic idea by giving it more thought, but I think it's a good starting point! Do let me know if I can help you with anything else!
Related
I have been struggling to find a good architecture, or even any nomenclature for what I'm trying to do here. I'm looking for nomenclature so I can have a starting point for research. And I want the same for architecture, but I'll take whatever anyone wants to help with.
What I'm trying to do & learn about
In a nutshell I need my clients to exchange pub keys, and other security data such as ACL ID's, name etc.
Current architectural attempts
I'm currently using my server as a via point, mainly because I can't see any other way of doing this securely and this method uses many layers of security. I also don't know of any other method of going client app to app securely.
A client creates group and sends pub key to server, opens a live query to receive other users data. Other user (with secrets passed to user) queries server for pub key, then sends own data to admin user via server. Admin then sends remainder of own data. I'm leaving out trivial security details but this is the gist of what I'm doing.
Issues
This is really just logical back and forth, but I honestly don't know what I'm doing. I don't even know if what I'm doing is right or the best way, I've also got a crazy infinity loop I'm trying to solve.
I'm looking for some terminology, description and/or architectural pointers, I'll take any input I can get.
Forget terminology, nomenclature and architecture.
Define the problem you are trying to solve in a simple sentence.
Break down the issues into smaller pieces (bite size).
You send A data to server
What happens to the A data
Any feedback or acknowledgement from the target host?
What sort of application is this? Web, Mobile, traditional client/server?
The most elegant solutions are usually the simplest ones.
Sit down and determine whether you have a problem to solve in the first place.
For a student project, we're working on connecting a Bluetooth LE device (that both transmits and receives) to an iPhone or iPad in order to read data from it to display to the user in realtime. We have proof that this is doable by the company that made the device and we've actually managed to get a connection and get some data.. however it pings every 5-10 seconds and seems to be a random subset of numbers with minimal changes after changing something on the device which is making us none the wiser.
Now, of course, we went to the company that made the device and app first and we do have approval for us to use their hardware, but haven't been able to get a SDK / API from them to use with the application. So, our plan is to make our own way through it and find what we need.
This is where we're getting stuck. We have the following:
Connection based on Name or Bluetooth Device Address
Scan services (and cascading scan in case the services have services within them as specified in the CoreBluetooth documentation)
Read Characteristics from said services.
Decrypt value into 8bit UInt so we get some actual readable data.
This is an example of what we've got with the value still as it comes in.
Service: 0x1c0476440, is Primary = yes. UUID: 058d0001-ca72-4c8b-8084-25e049936b31
value <53636da1 7a616c74 73616c74 73616c74 73616c27>
Now, looking at this all, I presume the service here is some kind of 'staying alive' ping and it's giving some auxiliary info about the device's current state.
The question we have then boils down to this:
How can we further 'explore' the device? We don't seem to be getting any additional output aside from this however looking in the device manager from windows we get a couple of hits that look like this (Example):
{058d0001-ca72-4c8b-8084-25e049936b31}[6]
Which have values in either a hexidecimal value, boolean or datetime without clear identifiers. Is there a way for us to send a message to the device to change the value in that uuid using Swift, or is this impossible?
While solved now, I'm not accepting this as the answer. My solution? Try things. Stupid 'Needle in a haybale' things.
I changed the uuid from 058d0001-ca72-4c8b-8084-25e049936b31 to 058d0002-ca72-4c8b-8084-25e049936b31
and voila. I could do more. I tried 3, and again, a new result and a working data stream...
#Paulw11's comment is also a good way to solve this issue we found out.
I have a lobby in which I want the users to be in sync. So when a user turns off his internet while the app is running, he should be removed. I know Firebase does not support server side coding, so the coding needs to be client side. The answers from How to delete firebase data after "n" days and Delete firebase data older than 2 hours do not answer this question since they expect that the user is online and they have an internet connection. So my question is if is possible to delete users when they got no internet? I thought maybe it is an idea to let the users update a value every 5 seconds, and when that update is not done, the other users in that lobby remove the player. This way is not good, since every player needs to retrieve and upload alot of data every 5 seconds. What is the best way to solve this?
Edit: to make it short, lets say each user has an image. The image should be green when the user is connected, and grey when disconnected.
Edit 2: after thinking it over, it is really hard to accurate present the connected users on a client-side server. That is why, if nobody has a different solution, I should add another server which can execute server-side codes. Because of the larges amount of servers, I would like to know which server I should use. The server should run a simple function which only checks if the users are connected or disconnected and can communicate with Firebase. If I am correct it should look like this:
But the server also needs to communicate with the users directly. I have absoluty no idea where to start.
If I'm not completely wrong, you should be able to use onDisconnect.
From the Firebase, documentation:
How onDisconnect:Works:
When an onDisconnect() operation is established, it lives on the Firebase Realtime Database server. The server checks security to make sure the user can perform the write event requested, and informs the client if it is invalid. The server then monitors the connection. If at any point it times out, or is actively closed by the client, the server checks security a second time (to make sure the operation is still valid) and then invokes the event.
In app in production I'm using onDisconnectRemoveValue, and when I close the app, the user removes himself from the lobby. Not sure how it works when you turn the device in airplane mode, but from the documentation it seems there should be no problem.
One thing: when you test it better do it on real device, the simulator have issues with turning it off and on, at least the on I have installed.
Edit: So i checked the onDisconnect when you put the device on airplane mode and it works! The question is, that it removes the user in about a 1:30 min, approximately, so if you read the documentation or ask the support, you may be (and only may be) able to find a way to set the time you want.
I am new to Raspberry and VOIP. I am interested to make a door intercom system using raspberry, as I read most of the post here and those are really helpful,one of the raspberry is acting as server (Asterisk and PBX). I was able to call using sflphonebut that was only for desktop mode and I am interested to call using CLI and for that I installed "PJSIP" as reffered by most of users, but don't have any idea what to do next (I mean how should i start). As it is written after installation I am supposed to try for "pjsua" and "pjsystest" in pjsip-apps/bin, but it doesn't ring any bell for me.
Sorry for my level as beginner but if you don't begin how are you supposed to masters it.
I shall be very thankful.
so i can't explain all of the stuff you need to know, but with this Site you should be able to register to you PBX. It's an documentation to the high level API of PJSUA. If you go further on that site they will lead you through the things you have to do to establish a call.
Although this can be very frustrating because there are many error that can appear. There are some python test application under pjproject/pjsip-apps/src/python/samples, here you should firstly try to establish a call between two clients to be sure you server is well configured.
Just for info, the dest_uri you have to give in the call.py is like so sip:ip:port and you have to change the values in the register.py to your client infos. Then run the register.py in one shell and the call.py in an other shell.
Hopefully i could help you over some barriers, feel free to ask if something was unclear.
I am wanting to give back to a small gaming community. The idea is to make an app that acts like a chat client to connect to the game servers. I am trying to grasp the concepts on how connections work through examples I've found on the web, since I am self taught by seeing examples.
So far the examples I found are for connections on the same network. What I need is some kind of example that will allow me to connect from different networks or at least an explanation on what I need to do. Also I need to be able to get around a router without with setting port forwarding on the router.
In the end the app will be connecting to the game developer's server but I need a working app before I get his permission to connect to his servers.
Any help will be most appreciated. If any additional information is needed to help just ask and I'll do my best to fill in the gaps.
That is a very broad question, but I try to give you as much information as possible from by point of view. As I'm not yet sure if you want to have a P2P Connection (game-application to game-application) or a standard server model, I will just mentioned different approaches to this problem.
Adobe has support for P2P since a long time. Read some FAQ, esspecially "How does RTMFP differ from RTMP?" (I try to choose Sources with infographics, as that helped me to understand it).
What you really should start playing with and making first steps in, should be NetConnection. This is the very basic Function that will allow you to communicate to a Server running e.g. PHP or connecting to a Flash Media Server (FMS). FMS is inpartcular interresting for you, as it really boosts the ideas what you game could do, but setting up a FMS is not that easy,to host a own instance is even more complex. So if you come to the conclusion that you want to travel the road of using a FMS, I can suggest you Onyx Server. They mainly marketing theirself as a Streaming service, but in reality you will get access to a FMS for a ok'ish price (FMS instances on Amazon were way worst the last time I checked).
The FMS basicly only a Flash AS2 File with some extra Commands. Your FMS can handle real-time (!) persistent connections (!) with any client that connects to it. Everyone is able to connect to the server at first, and you can then choose in your FMS Script what a client have to bring to the table to stay on the server or is rejected. After that, you have a very string tool for a Game. For example, you could have a game instance connect to it, tell the server that an enemy was hit and the server near-instantly (the speed is really amazing, there is no feeled delay, it really is instant. Its called SharedObjects) pass this information down to the enemy game instance. I used FMS only for one project and it was a very long ride to understand it and work with it, but it was a really nice experience, as you code the Server in the "same" language like the game itself (AS2, AS3 = ECMA).
If you dont want to spend money at this stage, you can use the Adobe RTMFP Instance at p2p.rtmfp.net. It is, as far as I know, only for testing and you will be rejected if you misuse the service for a real project, but for starting and testing it will do. If you use the Cirrus Engine, you can even follow this Tutorial. You will find sample code in there:
// Cirrus connect info
private const SERVER:String = "rtmfp://p2p.rtmfp.net/";
private const DEVKEY:String = "{YOUR_DEVELOPER_KEY}";
// Used to connect to the Cirrus service
private var _netConnection:NetConnection;
_netConnection = new NetConnection();
// Listen for status info
_netConnection.addEventListener( NetStatusEvent.NET_STATUS, onNetStatus );
// Connect to Cirrus using our unique URI
_netConnection.connect( SERVER + DEVKEY );
My adive for you would be: Try getting comfortable with NetConnection. It is really straight forward. When I first started using it, I had a couple of days struggeling and reading a lot on the web, but I learned a lot doing so. You should too. Use NetConnection and try to create two simple AS3/FLA instances of your code that both connect to the same domain (use the adobe rtmfp domain for now) and try to exchange some simple String-Data between these instances.
To take some of the pain of your shoulders, add the minimum amount of listeners to your NetConnection like so:
//Main NetConnector
nc = new NetConnection();
//Troubleshooting Listener
nc.addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);
nc.addEventListener(NetStatusEvent.NET_STATUS, status_handler);
//nc.objectEncoding = ObjectEncoding.AMF0; //Default
nc.client = this;
nc.connect("https://some-domain");
////////////////////////////////////////////////////////////////////////////////
/// CALL ERROR LISTENER
////////////////////////////////////////////////////////////////////////////////
private function status_handler(e:NetStatusEvent):void {
//trace("NetStatusEvent");
dispatchEvent(new CallEvent(CallEvent.CALL_NATIVE_NET_STATUS, e, true ));
}
private function securityErrorHandler(e:SecurityErrorEvent):void {
//trace("SecurityErrorEvent");
dispatchEvent(new CallEvent(CallEvent.CALL_NATIVE_SECURITY_ERROR, e, true ));
}
You will get alot of errors and netStatus and NetSecuriy Events. Flash will often run into Sandbox-Violation errors when you now know what you are doing. That can be frustrating but if you keep it up, google every error and compare you implementations with the implementation of others, you will wrap your head around this and can do really neat stuff with it.
I recommend you google sources and tutorials for NetConnection and stick to one that is on your level of knowledge.
Good Luck.