I want to create a project which will interact with the iPhone/iPad via the 3.5mm jack. There are a bunch of these accessories on kickstarter.com. Although, I could't find any SDK that will provide me the possibility to get data from jack input.
I have seen that some people at progical.com have a sort of SDK that can manage this kind of connection but they haven't answered me yet (I applied for their SDK few months ago). Is there any alternative for that? I want to make this project in order to get my degree so the Apple MFI won't apply.
The project will consist in a bunch of sensors that will send data to my app using 3.5 audio jack. Using my app, I will process the received data.
The 3.5" Jack connector is originally supposed to send and receive audio data. It means that if a connection is plugged in, the OS will automatically redirect all audio signals to it (with a few exceptions). Thus, you can access the data using the built-in audio processing APIs of iOS, for example CoreAudio and audio queues.
As an example, you can generate and receive signals of different frequencies, which can be used to control and get information from external devices (you'll need some kind of electrical engineering for this to work, though - filtering, separating control frequencies, etc.).
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We are developing a mobile application that tracks users while they are picking up and delivering commodities. We have overcome many issues, including poor connectivity in rural areas, the app going into the background, and so on.
One issue continues to befuddle us. When receiving calls some drivers lose connectivity, other drivers will gain connectivity, and others (most) have no change in connectivity.
I remember earlier that Verizon iPhone users couldn't access data while on a call. Naively I thought that this issue was completely overcome, but perhaps it is not.
My understanding is that a) there are still some cellular protocols that cannot handle voice and data and b) there are (or were) some settings in mobile phones that give the user a choice.
I have searched for some list of cellular protocols and iOS and Android settings but so far come up empty.
Any guidance would be greatly appreciated.
Hopefully this will provide some more clarity; it all depends on the Radio Access Network (RAN) technology they're using (2G/3G/4G) and the terminal itself's capabilities.
There's 3 umbrella terms of technologies, each with their own revisions and variants, but this should cover it:
LTE (4G) only supports voice calls via VoLTE (Voice over LTE). Calls made over VoLTE will allow the user to continue accessing data at the same time. Many devices & some networks don't yet have VoLTE capability, so they use Circuit Switched Fall Back (CSFB) to drop to a 2G/3G Radio Access Network for making voice calls. (If your terminal does this you then have that RAN's ability to allow simultaneous voice/data.)
3G - There's a few flavors of "3G", depending on the terminal and the RAN variant (UMTS / EDGE / CDMA / HSDPA / HSDPA+) you may be able to access data and be on a call at the same time.
GSM (2G) does not have this functionality, the handset is either in Circuit Switched (Voice) or Packet Switched (Data) mode but not both.
The decision of which RAN to use is based off the priorities stored in the SIM/USIM, the received signal strength of the available networks and the capabilities of the terminal.
This means for example your users who may gain connectivity may find themselves using a 3G access technology on a 4G enabled terminal, with VoLTE support, jumping up to VoLTE to make the call. (Some operators resell to MVNOs but default to slower / older RAN technology like the 3G family)
Others may loose connectivity as you've seen, if they're happily using LTE on a device with no VoLTE support and need to drop to 2G/3G for a call (CSFB) they may loose data services as they're back to the limitations of these older RAN technologies.
I am trying to set one pin of the old iPhone 30-Pin Connect from low to high so the best would be from 0V to 3,3V. Is that possible with a simple PodBreakout board like this?
https://www.sparkfun.com/products/8295
If not can you send a constant voltage out of the iPhones audio jack (This could be a good method too, cause now apple used its 9-Pin Lightning Connector).
I already searched the web, some say you have to jailbreak your iDevice, some say you need an authentication Chip, and some say it works flawlessly without an authentication chip, but I cant find any help online.
Thanks
You can't "send a constant voltage" out of the audio jack. There is a series capacitor there that filters out DC and very low frequency signal components.
To get proper help on this you can apply for the MFi program. I think it's free for educational purposes. It's under 100$ for sure. There is an NDA involved.
If you want to avoid the MFi you can always use BLE to communicate with periphery.
Or try to implement software FSK (or DTMF) modem on one side and a hardware one on the other side (using the audio lines).
Since it seems you simply want so see a binary (on/off) signal - you could generate a fixed pitch tone in the app (2kHz for example) and use a narrow-band filter on the hardware side (audio-jack connection).
Or maybe (to make sure your app is present on the other side a 2kHz tone would mean 0 and a 4kHz tone could stand for 1.
The authentication chip (and an MFi license)) you are talking about is needed when you try to communicate with the iOs device:
via BT (excluding BLE)
via USB (30 pin connector or lighting connector)
via UART (30 pin connector or lighting connector)
I am currently trying to develop an application that uses the device camera to record video. Currently i am using an Apple demo that gets the data incoming from the camera and display it in a layer. In a second phase i started documenting about how to transfer that data via Bluetooth and/or Wifi to an other iPhone (real time local streaming), but i am getting no information about whether this is possible or not. Some posts say that this is limited due to the limited maximum data transfer size over wifi or Bluetooth. Could anyone tell me if this is possible or not ? Could anyone give me an example ? Thanks.
Sure you can at least for WiFi. With Bluetooth there may be some issue with bandwidth. For network library, there is this excellent library with example that you can start with. You will need to learn at your own pace. Good luck!
I'm working in app where I need to implement a simple voice functionality between two iOS devices in same network.
My doubt is about how to get audio units from master device and send over wifi or bluetooth network directly to slave device in realtime.
Some things about network communication I have done, I can transfer any NSData between devices using TCP.
Is very important to not use GK framework, because I need to connect two clients without any notification. For example, when I use GK to connect two devices, the iOS display a alert with a connection request, I need to avoid this connection request.
Currently I can do this with video, is more simple than audio.
Any ideias about the implementation of this are welcome.
Thanks.
First of all, you need learn how to capture the audio using Audio Queue Services.
Then transmit the audio data it over wifi and bluetooth and play it at the other side.
The most obvious choice for you is to use bonjour.
GameKit framework is built on top of this. You dont have to build too much on top of this for your application though. Yours is a straightforward application of bonjour.
Please refer the code for chatty if needed. Incase you need some background theory, please refer to http://mobileorchard.com/tutorial-networking-and-bonjour-on-iphone/.
I have used Audio Queue Services for the same sort of project.
For Networking I am using Bonjour and it has really solved the problem of transmitting text and video.
Did a lot of workarounds to make a voice chat in wifi using Audio Queue Services but have not succeeded. I will update once I find the solution other than this.
I'm developing a custom electronic device - think of it as a special kind of data logger, and I need to connect a computer to it to configure it and to extract the data.
I know I can do this without too much trouble on a PC, but I'd like to use an iOS device to do this.
Two questions:
Can I do this with a regular dock connector / USB cable? Will the EA framework let me do all the communicating?
Once I have extracted the data, what's the best way to get that out of the iPad? Make an email with it, save to a dropbox or something?
Thanks!
Afaik, you need to join the MFi program to make USB accessories for iPad/iPhone. That will give you all the technical resources needed.
As for data transfer there are only "opinions", I say the more options of sending, the better. Just don't force the user to choose more than once, then make it changeable in settings.
If you're doing very light communication, you might be able to get away with using the headphone jack.
Apps communicate to the headphone port through the various audio frameworks on iOS. AVFoundation is a high-level abstract framework to do various audio operations, but for fine-tuning the communication to a device over this interface, you will likely be using the C-language callback-based Audio Queue Services framework to do audio I/O.
This is nice because your device can be cross-platform (iOS, Android, Mac/PC) as long as you write the corresponding software, and because you don't need to go through Apple's MFi approval program. Think like the Square credit card scanner.
You will have to write the communication stack between the device and your iOS device but yes, you can.
there's very few docs about using the EA.framework. All the juicy parts are in the Mfi program but Apple is very strict about giving access to it.
So if you succeed, sharing a tuto will make you a EA hero ;)
About sharing your data, imho, email + CSV is a winning combo.
If you want to plug something into the dock connector, you want to have a look at https://developer.apple.com/programs/mfi/