I was always wonder what would it be my first question on StackOverflow since everything I'm looking for is already asked. (Find only one similar here Bluetooth data transfer between two countries )
BACKGROUND STORY:
From when it comes I’m a fan of Nokia N-GAGE. It’s a Nokia’s phone from 2003 with dedicated games. In its heyday 2003-2007, it has single-player, multi-player via Bluetooth and using a dedicated internet service N-GAGE ARENA for compete with people all over world.
N-GAGE ARENA servers were disabled about 2008 and as far i understand It isn't even worth trying to resurrect such a infrastructure. Mainly because it requires modifying the code of each game and that's illegal.
Multiplayer mode using Bluetooth work fine, but requires opponent 5m away max.
Nokia sold 1mln copy of this phone, and still are people all over world collecting n-gage games. I have a dream, I want to reactivate the possibility of playing multiplayer with people from all over the world.
PROBLEM DESCRIPTION:
I want to use the Bluetooth multiplayer mode by extending the usual N-GAGE to N-GAGE Bluetooth connection with an additional 3 elements. Two N-GAGEs, instead of connecting directly to each other as host-join, connect via a PC / smartphone applications that communicates with the server that transmits full data sent from the game of one user to game of the opponent.
I admit that I do not have full knowledge of technical limitations. In my opinion, as a software engineer, it is theoretically possible, but I want to consult you, people more familiar with the subject. Maybe someone is working on a similar project and can comment.
WHAT DO I KNOW:
The application would have to transmit all data from the Bluetooth connection so as not to disturb the illusion of a direct connection between N-GAGEs.
The application must enable the selection of an opponent on the basis of the game. The choice itself could be made on the basis of some kind of chat in which users first define what they are playing, who’s the host, and then the connection is made.
WHAT DO I WANT TO KNOW:
Does what I describe is even possible?
Is such capturing Bluetooth connection and forwarding is even possible?
Does the development of technology in these 15 years allow me to transfer Bluetooth connection real time through 2 additional devices and Internet connection?
I WOULD BE GREATFUL FOR:
Any technical tips, literature that can help me to understand my limitations.
Any constructive criticism. Of course before I start doing such a project I have to confirm that isn't a utopia. For me It’s a side project, I’m able to spend years on it, but don’t want to get to dead end after all effort.
Does what I describe is even possible?
Yes, yes it does. Your hardest part will be setting up a tranceiver to interpret the I/O. Your failure point would be super-encrypted messages and making transmission difficult...
If it's clear I/O you can signal this through any server and output it back to the tranciever to output. Confusing but possible just not sure of the design or how bluetooth sends its data.
Is such capturing Bluetooth connection and forwarding is even possible?
If a connection is possible then forwarding it is too. Considering this piping the transports.
Does the development of technology in these 15 years allow me to transfer Bluetooth connection real time through 2 additional devices and Internet connection?
Bluetooth real-time no... with added network latency, you're looking at anything from 1-200ms~. you may be able to improve it?
Overall I think if you can:
Connect the device to PC, and have PC talk back to device through blue-tooth
Read the data that goes in and out
Encryption proves little or none at all to be able to signal the data properly, tricky to explain you'll know though if there's a wall.
All should be possible it doesn't overly go against the grains but do more homework this is very valid.
Related
As I understand it, Bluetooth Low Energy communication can be established with or without pairing. This is in the context of mobile development, Android more specifically but I believe iOS is more or less the same.
Are there instances where one would choose one over the other? And what would be the purpose? What is technically considered paired communication and what is considered unpaired communication?
I've dabbled around for a bit on the differences and have even made a few demo only apps related to BLE but I haven't found a clear explanation if what I am doing is actually considered paired or not.
Edit:
The reason I ask the question is that I believe I am looking to encrypt unpaired BLE connections. In some cases, and essentially my main use case, a mobile device may want to connect to several different peripherals randomly at different times throughout the day and the process of physically accepting a pair request seems unnecessary and quite time consuming. By 'randomly' I mean I am walking by one if I have a dozen scattered around my apartment and I personally don't know exactly which one without physically checking. I don't what to walk in the room the first time and have to manually pair each device, that would be insane if I had 100 devices. Note that these devices don't necessarily have to be connected at the same time, but could. Also note that I understand this isn't generally the main use case of the typical peripheral to mobile use case.
Here are a few differences:
If you bond the devices, the link will become encrypted, so it becomes more secure. So "paired" communication basically means the link is encrypted plus the device "knows" what it talks to.
The remote device also learns your phone's IRK (identity resolving key), which can be used to identify the phone later on. By default, the phone rotates the Bluetooth Device Address every 15 minutes or so. Without knowing the IRK, the peripheral can't identify the phone.
A good thing if the devices are bonded, is that the GATT db of the remote device gets cached, which means upon next connection, you don't have to wait a long time for service discovery to complete.
On Android, connecting by Bluetooth Device Address without first scanning is broken since the API lacks the "address type" bit (public/random address). If Android "guesses" wrong, you will connect to the wrong device and therefore fail. However if devices are bonded, the address type is stored and looked up based upon Bluetooth Device Address, which makes it work as expected. So if you plan to automatically connect to your peripherals in the background upon boot for example, it's a good idea to bond the devices.
A small detail is that Client Characteristic Configuration Descriptor values should also be stored by the GATT server and restored once the bonded device reconnects so it doesn't have to rewrite the descriptor value.
Some Bluetooth profiles needs bonding, for example HID (at least on iOS and Android).
So I'm kinda stuck here.
I have a radio station, but we are mobile. So I have a studio on wheels. The problem is, we have an antenna, but we always have to place that really close to our studio. Now I want to make an device that can stream the audio from the audio mixer to the internet and can be received by another device in another network and send that signal to the antenna (audio output).
to make this clear, I made a schema with raspberry pi's;
I want this to be plug and play So I only have to plug in the device in the modem (or network we have) on both sides and the devices should find each other.
I don't know HOW I can do this, so I need to know a couple of things:
What hardware should I use?
What software should I use?
What is the best configuration to accomplish this?
Can I use 2 raspberry pi's?
How can I let the devices find each other over the internet?
There need to be some features;
The system needs to be able to buffer the audio for 5-10 seconds
It needs to be direct, so it's live and not a file that needs to be played
The system must be failless (beside the fact the internet can die).
Plug and play is a must, I don't want to have a really messy configuration to do. (if possible, without any kind of portforwarding).
I would really appreciate help and a decent explaination.
regards,
Robin
Well, it depends on your capabilities as a programmer.
If you're really fixated on the RPi for it's convenient form factor, there's a ton of community support, so I'd start with something like this project to kick start you in the right direction. If you already know python pretty well, modify away and have fun.
If you have no programming experience, you'll probably want to put a desktop in place of the RPi and launch some instances of VLC. It's not necessarily plug n play, but you can get close enough by getting a command line VLC to launch at startup.
Either way, the more difficult problem here is the "over the internet" part. This would really need to be a server-client model, but who is your server depends on who is more stationary (I'm guessing Location 2?) because the client will need to know the IP address of the server somehow. There are dozens of ways to make this happen, but at the end of the day, you'll want to use sockets accomplish the
It needs to be direct, so it's live and not a file
... which unfortunately gets complicated. See this answer for confirmation. Would love to help with some tips on implementation, but we need more information about your willingness to "dig into the code", the necessity of the RPi, and whether the stationary location has a static web address.
I have been tirelessly trying to decide on the best option for getting phones to talk to each other that are nearby, I need something with the ability to broadcast and receive. It is kind of like NFC with more range, I'd like to be able to send messages 30 to 50 feet away using nothing but a phone.
Bluetooth cannot broadcast and receive to more than 8 devices still, there might be changes to that in Apple's new OS but Android and Windows are still going to be lacking, so Bluetooth is out of the question.
I was thinking of maybe trying to use Wifi, but I have not found very many good resources on how I would go about doing that without making a virtual server, I'd much rather not go that route if possible.
I could even use GPS although with the power consumption of GPS and having to be an always on feature I am not certain I would like to use GPS if I can avoid it.
The one I really want to use, uses sounds made and received by the phone. I have been playing around with a listener that converts different frequencies to 1's and 0's, but with all things sound, it gets increasingly hard if lots of people are talking, or there is music playing, or if there are objects in the way, the Doppler effect and more. Is there someone out there who has already made a filter for this? Some other problems would be, what is the range sound travels at 20khz through air? I can also not find much good documentation anywhere for devices whose speakers can make sound above 20khz but it seems most can, the problem then is what microphones can hear sounds above 20khz.
I would really love to use sound as I think it is interesting, and it would make the app work without any internet or phone connection which I think is pretty cool. This is a side-project I am working on, and really don't want to spend hours down a path that will ultimately fail.
If anyone thinks it's possible to do this with sound over other devices, I'd much rather like to do it that way, I think there is a lot of interesting things you could do with that technology, I just don't know how viable it is over using wifi or bluetooth or even GPS.
At ios you have no controll to low level "things". You can read the current connected wlan ssid, but not all wlan ids which the operation system can see.
I would first try the location services approach. Settig to 1000m acuarcy will usually disable GPS, but enable cell-tower an wlan locationing.
Especially the wlan locationing gives an indirect hint that the persons are near the same wlan
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I am interested in Bluetooth 4.0. Where to start adventure with it? If you have any materials, links, books I'll be very grateful. If you could share this knowledge. I would to use BT 4.0 to connect a PC (no matter what system) with a smart phone (eg. Windows Phone).
Right, I tried to quickly put together some relevant information that might help you. There is a big chance I have missed thing because this is a broad topic.
I am pretty sure you will find help here when you will have more specific questions.
Basically when it comes to Bluetooth (Smart, 4.0) devices and programming / connecting to them we can talk about two things:
Bluetooh Clients and Servers
Servers:
usually provide some data to clients. Think about a Heart rate monitor that captures someones heartrate and "stream" it so anyone who connects to the server will be able to read the data.
Clients:
On the other hand clients connect to servers (how obvious) to collect their data, or in some cases to write to them.
Bluetooth Profiles
Bluetooth devices (servers) have so called GATT (generic attribute) Profiles. These profiles describe a kind of unique set of Services. Each Service has different Characteristics. These characteristics hold the actual values.
Think about a Heart rate monitor (HRM). Thats a server. It measures heart rate so clients that connect to it can read / collect it's data. Heart rate monitors have a specific Heart rate monitor GATT profile which describes services and inside the services there are the heart rate specific characteristics like: heart rate measurement, body sensor location, etc.
When a client wants to read these values it has to connect to the HRM, discover it's services and characteristics, then read the values from the discovered characteristics.
Async
It might be obvious but Bluetooth programming (implementing server / client connection and data transfer) is async. It means the client sends something then waits till the server answers then can the it progress to the next step.
Your whole software has to be implemented keeping async programming design in mind.
Documentation
I have to say I found the iOS documentation and support very useful when I developed my first bluetooth app.Android was somewhat more difficult for me because of the lack of examples I found. Also general bluetooth 4.0 support only became available since Android 4.3. (different bluetooth chip manufacturers in different Android phones had different low level bluetooth stack so to use them one had to write native bluetooth code for each different chip with their own SDK - prior to Android 4.3)
Bluetooth.org
I would suggest to start with this:
https://developer.bluetooth.org/DevelopmentResources/Pages/Quick-Start-Kit.aspx
https://developer.bluetooth.org/TechnologyOverview/Pages/Technology-Overview.aspx
https://developer.bluetooth.org/DevelopmentResources/Pages/default.aspx
https://developer.bluetooth.org/gatt/Pages/default.aspx
iOS
It won't hurt if you read about Core-bluetooth framework, which is the iOS approach even if you don't plan to develop on iOS. Since it is well documented it might give you a better overall understanding:
https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/AboutCoreBluetooth/Introduction.html
Android
Same for android:
http://developer.android.com/guide/topics/connectivity/bluetooth-le.html
Windows 8
http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj207007%28v=vs.105%29.aspx
I've found "Bluetooth Low Energy: The Developer's Handbook" by Robin Heydon very useful. It deals with all the little details so you can understand how things are working on the lower level.
As a reference, I've found the Bluetooth specification PDF very useful (though it's sometimes hard to find what you need). It looks like they just released a 4.1 version here: https://www.bluetooth.org/en-us/specification/adopted-specifications
EDIT: both references aren't specific to any particular implementation, so I'm not sure how much they'd help if you wanted to learn something specific like iOS BLE or Android BLE.
I am experimenting with Bluetooth Low-Energy (BLE) for the purpose of connecting a hardware device to an Android application. My goal is to send a recognizable piece of data to an Android phone.
I am using the keyfob from Texas Instrument's CC2541 Mini-development kit, and am programming it using the IAR Workbench (which I am learning on the fly). My issue is that I cannot figure out what code should be used to send data from the keyfob to the phone.
I understand that this is somewhat vague, but because of the non-disclosure policies of my company I cannot share the code that I am working with. Does anyone have any references to code for the IAR Workbench that will allow the CC2541 to send a piece of data? Right now, I prefer to use GATT if that helps.
Thanks, and please ask me more questions if I need to clarify anything.
Assuming you're working from a pre-existing service profile, there is a function for every service called ServiceName_SetParameter(). Calling that function will change the characteristic value. When the characteristic is read by the phone, it will receive this value. If the characteristic supports notifications, and your phone has registered for notifications on that characteristic, the new value will be transmitted whenever SetParameter is called.
You can implement any proprietary protcol to connect to and interact with your beacon device. It can assume other roles than just the beacon task. It can also listen to and respond to connection attempts thus expanding into a lot more than a regular beacon.
If you study the cc2541 close you realize it is a pretty advanced IO controller that offers a lot of IO signal possibilities. That way you could use the cc2541 as the heart of an IO control application where you measure and control equipment. Mobile apps can then easily connect to your beacon/IO Controller device and interact with the machinery it is hooked up to. As you see, it´s a remarkably versatile system on chip and a cool circuit to learn to program.