As a final school-graduation project I try to develop a kind of spying-car. Which means there is an iPhone placed on a little LEGO-car and an iPad used as a "steering wheel" for the car. Also it is planned to transmit Audio and Video from the iPhone's microphone/camera to the iPad (more than the steering data vice versa).
In the first place the connection from iOS to iOS should be established over a local WiFi network and later - if possible - over 3G (by using the iOS devices network-IP and a DNS server to deal with frequently changing addresses).
My question is: which technology do you recommend using? I read about GameKit, peer-to-peer and so on, but I think these technologies are too abstract for later being able to communicate over 3G. I guess I need to go a little deeper into the low levels of the communication progress. Any suggestion that could bring me a step forward is highly appreciated! (also regarding other parts of my project)
One more thing: Some user suggested using a third party service and to route the sent (video) data over an external server. If possible, I'd rather not use any "middle man". It should just be a basic server-client communication where the iPad is the server and the iPhone the client.
It is kind of an open ended question, but interesting.
First of all, GameKit do have 3g p2p support, see here:
https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/GameKit_Guide/Matchmaking/Matchmaking.html
It will handle the peer-to-peer addressing and establisment of the socket. It can also handle voice chat, but I personally never tried this feature so I can't say if it is feasible in your case.
One idea is to leverage existing video-chat services. This will give you a low-latency audio/video channel with peer-to-peer addressing (well, likely using a central server).
Apple's FaceTime is such a service, but there is no public API to it (AFAIK). Same goes for Skype and Google.
There are some paid services that look like they have nice iOS APIs:
http://tokbox.com/platform
http://docs.weemo.com/sdk/ios/
You have to figure out a way to transmit control commands to the peer iPhone, I did not see if the services above had any possibility of sending text messages/arbitrary data.
Tokbox has a free trial so you could try it out and see if it works for you.
I would go for GameKit if this is a hobby project on a budget and there is time for hacking, and probably look into a more high-level API if there is a deadline...
sorry for writing this as an answer, but i don't have enough rep to comment...
i'm working on a similar project and i currently don't have any advice regrading video-streaming, however, from what i read (extensively) i came to the conclusion that i need to use p2p connection between devices for better performance and use socket programming in order to achieve this (although not the most easy to implement choice).
I considered using GameKit which i think will probably answer most of your needs as Krumelur pointed out. but in my case, eventually the app will be cross platform so i had to use low level network programming. you can check out my question here to see the sources i used to try and make the connection between 2 peers, hopefully you'll have better luck than me...
I'm nxj beginner.
I have some questions about bluetooth communication between PC and brick.
First, when bluetooth communication occurs, where is the birthplace processing this datas?
In other words, I want to know whether these datas will be processed on CPU or brick.
Second, what is exact roles CPU and brick in bluethooth communication?
That means what is processed on CPU and what is processed on brick.
I have searched almost web site but I can't find this anywhere.
Please help me. Thanks.
You can see it in the package structure.
lejos.nxt.*
This package contains classes running on the NXT-brick. All code in this package will be compiled for the brick and will run on the brick.
lejos.pc.*
Here the difference is not that clear. This is java-code you compile for personal computer. So most code runs on your computer. But some classes (e.g: RemoteMotorController) only send messages to the NXT-brick which gives commands to the motors.
lejos.pc.comm provides API's that allow you to communicate/control the nxt robot from the PC.
When importing the the libs to an Android project, it allows you to build an instance of the same environment used on a pc, but within android.
I agree it can be tough finding some things out. It would be great if there was as stronger lejos presence on SO
This question is months old and has remained un-answered I actually have a lot of questions about it myself, but I might be able to provide some insight for utter novices.
when using bluetooth with Android and NXJ robots, you use either lejos.pc.comm or lejos.NXJ.
Both provide APi's to do almost the same thing, but work a little differently. I don't know nearly enough about the NXJ api, but I do know that it is the one that lets you manipulate the robot much more effectively, such as outputting data to it's LCD screen, which you can't do with the pc.comm api
As far as I can tell, the pc.comm API uses both Android Bluetooth API's and it's own protocols to allow communication with Lego LCP commands.
(I want to come back to this, but I'm writing a dissert on the topic so I'll try to update it in a couple of days. Seems not many are interested though, shame)
All,
Apologies in advance - this question might be too open-ended for SO.
Anyway... A friend of mine (an engineer and entrepreneur) is in the process of building a high-tech piece of lab equipment. He's asked me about the feasibility of building an iPhone/iPad/iPod application that would allow users to control the device via Bluetooth, so I'm helping him gather some information. I'm hoping to get a few pointers on how to get started. Specifically:
Would this require a native app, or could this be accomplished with HTML5 (with or without something like PhoneGap?)
Can you point me to a good primer on bluetooth networking? Everything I've found assumed a VERY high level of pre-existing knowledge.
What are the basics on how something like this is accomplished? Is there a single, established protocol for how one device "controls" another, or is bluetooth more like SSL - just a pipe that allows you to convey any type of message?
I realize this question is incredibly broad and detailed - so I'm not really looking for specifics. But obvious Google searches don't turn up much, and I'm otherwise having a hard time finding a good starting point.
Thanks in advance.
You can communicate via bluetooth in two ways: One is using the Low Energy Bluetooth capabilities of iOS 5 and newer iPhone/ipads.
https://developer.apple.com/library/ios/#documentation/CoreBluetooth/Reference/CoreBluetooth_Framework/_index.html#//apple_ref/doc/uid/TP40011295
Unfortunately the documentation is sparse and will require some hacking away. If you choose this route I would consider starting here and learning as much as you can about how the protocols work before hacking into the framework:
http://developer.bluetooth.org/gatt/services/Pages/ServicesHome.aspx
The limitations of this route are that it might not be best for sending a lot of data. I have only built stuff that sent simple commands which it does work great for.
The other option is the external accessory framework. This will require you to get an mfi license from apple (not fun). You will also need to pay royalties. But it will do what you want. You won't need to concern yourself much with underlying protocols if you use this, the framework provides a friendly api for processing streams.
http://developer.apple.com/library/ios/#documentation/ExternalAccessory/Reference/ExternalAccessoryFrameworkReference/_index.html
I asked questions a month ago about a project where an instructor has an iPad and a bunch (oh, 15 we'll say) of students have iPod Touches. The students need to send answers to the instructor and the instructor needs to issue new questions to the students. From what I've been researching, bluetooth connection using GameKit only allows up to four devices. Since I need more than that, I know I need to deal with wifi connection with GameKit. I have tried to find tutorials, example code, etc. for this, but I just keep finding people saying "you'll have to implement it yourself." My question is, how do I go about implementing wifi with GameKit? Brian mentioned a hosted match that can have up to 16 devices, does anyone know of a tutorial or example on hosted matches? Any links would be very much appreciated, I just really need a place to start!
You can use Bonjour Framework instead of gamekit..
it allows you to create server and connect as many clients to it .
publishing the service etc all can be done..
For reference follow the following Book :-
Beginning.iPhone.Games.Development by PJ Cabrera.
I've worked with folks who are chatting online with their peers, constantly batting around ideas. I've also worked with folks who adamantly refuse and think it's a waste of time.
Are online live chatting forums of particular use to you? Why or why not?
Internal to your company, or external and world-wide?
Does your employer encourage or discourage their use?
Update: I see some people are voting this question down, yet so far all the answers have been positive, if with some reservations. If someone has a strong negative opinion (I hate online chatting and think it should be banned etc.) I'd really like to hear why.
If you have telecommuters, not chatting online will be the death of you.
Without chat, there is no interaction.
Without interaction, there is no problem solving.
Without problem solving, the code will suck.
The chatting part does waste a lot of time and I often wish I could just pull them out and just WriteSomeCode, but yeah, trade off scenario.
There's an additional benefit to using online converstations, in that it doesn't /have/ to be an interruption. If your working on something you can ignore them till you're done and they just have to deal with it. In real life you have a talking face to try get rid of. ( And the cool thing here is you can ignore them and they still get heard, have your cake and eat it too! )
I've used IM at the last three places I have worked. Currently the building that I am in is so large that it takes a couple of minutes just to walk to my managers office. Then there are the days that we work from home (1-2 days a week). Email for some purposes just doesn't cut it and the phone can be too disruptive and all encompassing for some tasks.
When I was doing consulting work I would give my IM contact information to my clients. About 25% of them would use it to contact me and I am still in contact with them to this day which opens up the possibility for future work! The clients that used IM felt that they had a better connection with me because they could see when I was online and available to talk.
I'm still in contact with old work colleagues through IM and this allows me quick access to their knowledge base as well.
My suggestions for using IM in the workplace are:
Use a client that supports multiple
protocols (MSN, Yahoo, AIM, Jaber,
etc)
Setup and use personal accounts for
each of the networks you are on
(i.e. don't use accounts tied
directly to your work)
Make sure your IM client records a
history of all of your conversations
Always be available but minimize
personal conversations
Provide your IM information freely
to friends, clients, and colleagues
Add appropriate groups (i.e.
friends, family, work) and filters
to reduce undesired interruptions
while still being available if
needed
Don't feel that you have to
respond to every chat request. Let
it set until you are ready to deal
with it
One other trick I use is to use text to speech software so that when a chat message comes in it is read allowed. When I am at home (or preoccupied away from the computer in the office) the message is automatically read allowed (I liken it to a ringing phone call) in order to get my attention. But, I don't have to stop what I am doing in order to know what the message is.
I used to. I found it a great resource to chat with people I used to work with. In our business I find that we tend to network alot and using that collective knowledge is awesome. Of course my company turned that off so they lose.
I know that a certain large Bank hasd an internal AIM setup so that they can IM each other. That was refreshing and dang useful. They also allowed some external access. Talk about getting the value of IM!
Yes, absolutly, I work with most of my employees, and employers via MSN/Yahoo/Skype/.../ it makes the work easier, because I can hire the better people without having to pay them to move to me.
When I need to collaborate with someone in another office, it's great ... when I'm deep in thought, I have to turn it off (just like e-mail).
It depends on the group dynamics and personal preferences. Personally, I have enjoyed my work groups that use chat to feed on each other's ideas and troubleshoot without as much walking around. If you are geography dispersed, its almost a necessity.
I find online chatting invaluable in many cases, but not normally instant messaging. Since I use many open source technologies at work, I tend to join the respective IRC channels, both to ask questions there, and sometimes to help others if I know the answer offhand.
It may depend on the work environment. As a self employed consultant, I'm always in chat - it's my primary communication to the world, along with emails for more official type communications.
Being able to converse with others creates synergy, but it also can cause distractions. A good manager can tell the difference.
At my last workplace, we used IM extensively for collaboration. Not so much at my present workplace. Infact, i have not once had to do that here in 6 months. But i do look around on the net for answers and sometimes i have posted queries on forums too. IM is a nice tool to have, but its also a time sink. Also, dont underestimate the lost focus. Its particularly hard to concentrate on getting that algo implemented right if someones constantly pinging you about how to establish a connection to an oracle database.
I work at home 2 to 3 days a week. I mainly use MSN to stay in touch with my coworkers. It's pretty useful to ask short questions quickly. If we find ourselves typing whole conversations we often agree to continue the conversation by phone.
I use IM to communicate with colleagues in other offices when it replaces a face-to-face chat. I turn off notifications in all my comms apps at work though, because they distract me otherwise.
I telecommute from California to Colorado and never have used chat. We do have daily SCRUM meetings and constant email threads. When I first started working remotely, we did try it but it seemed intrusive to several co-workers so we stopped using it, that was 4 years ago, I probably should give it another try.
It seems I have nothing to really add to what hasn't already been written.
I use it extensively, especially when remote people are involved in development. Without it your real time communication dies. It is the only viable method of communication that isn't as interruptive as phone calls or something of that nature. As we all know we can't just sit on the phone the whole time when developing, so chat is the next best thing for real time communication.
I personally don't like it. I think email allows you to take a little time to compose your thoughts.
IM seems to work for other people though. Whatever works!
Our entire business unit telecommutes. Only us first years are required to be in the office, so our enterprise IM solution is vital to staying in touch and on task. Its how my manager lets me know what project I'm working on, if I need to bill my time to another customer, or if I need to bounce ideas around. So yes, I do. Is it open for anyone to get on? No, not at all. You have to be on the intranet to access the system, and it is closed to any and all outsiders.
Out of the four professional jobs I've had over the past 8 years or so, I've only worked at one place that did not allow any type of instant messaging. All the other companies had at least some type of setup for intranet instant messaging.
I think that IM is almost necessary in today's business environment. I don't IM very much, but it's nice to have it available. Especially when I just need a quick answer to a question - like "Where is this file located?" and then boom I have a link to the file pop up right in front of my face.
I use IRC at work - it's almost a requirement for all of us who interact remotely (workign from home, different offices, and client sites) to be able to get help on problems fast.
Yup. It's actually required here. But only MSN though. We use it for development/task related communications with the team... which also help minimize noise since this company I'm currently working in is a big one where 90% are developers so utter silence is a MUST...
But if I've got questions to other members of the team, I prefer asking it personally though because I find it hard to explain some things when just chatting...
I've had to use it in my last job as my co-workers lived in the UK and my boss worked in California whereas I'm in Atlanta. It was used for quick questions and when it was "whenever you get the chance to respond" type thing. I could be on the phone and an IM pop-up and they would get an automatic message telling them that. Longer discussions were done with web cam and telephone and the ability to share a desktop to view code, data, etc.
My company won't allow it. Even if we run a IM server in house (so we aren't wasting time chatting with friends). I've tried to convince them, I find it really useful for knowing if someone is at their desk or not. The phones don't do that so well since if you don't pick up it redirects to a secretary that will get pissed if you are checking if someone's back every 5 min...
So I run a IM client on my phone so I can at least chat with a few people through out the day. (Less interrupting to others if my wife IMs me vs calls me and also easier to ignore if I need to).