I have a fitness app that is already in the app store and now I want to implement a bluetooth device that users can purchase if they wish. This is my first time dealing with bluetooth and after reading "Core Bluetooth Programming Guide", I have the following questions.
My app contains information that my bluetooth device requires simply to display the data. If I'm not mistaken, this makes the app the "Peripheral" because it has the data. The bluetooth device wants the data from the app so that makes the bluetooth device the "Central". Am I correct about this?
Finally, here is where I get confused. The bluetooth device has a button that I want when pressed to trigger the app to get the app to send new values to the bluetooth device. Is this possible? The reason I ask because in this scenario, would this now mean that the bluetooth device is the peripheral and the app is the central? If yes, will I have to break the current connection between the two in order to switch their roles (manager, and peripheral)?
Thank you in advance, really appreciate it!
Ted
As you have control over coding the app and coding the device, you can make it work either way around (Assuming the device is to be used specifically with your app and nothing else).
Both central and peripheral have methods to read and write data from/to the peripheral.
Without more information on the data and how often it's updated, it's difficult to suggest the best way to do it.
You say your device will have a button that will tell the app to send data over to it, well the app won't need to send anything it simply keeps values up to date then your button would tell your device to read the latest value.
Or (Again without knowing the purpose this may not suit) you do away with the button completely and your device subscribes to a characteristic in the app and is notified every time the value is changed by the app.
Related
We're looking to build a small device connected to a sensor that transmits data to an iPhone, which subsequently takes the data, stores it and graphs it. However we want the iPhone to be able to change the polling data on the device by sending small amounts of data. I've been doing some reading and it seems like bluetooth LE does not allow for this type of streaming connection. Is this correct? Would switching to an Android platform be better? What would you all suggest?
With Bluetooth LE, you have complete control over the flow, even on iOS.
That said, there are a couple of things to know:
BTLE devices only have read-only "characteristics" (but can be dynamic)
There is no way to "push" data, only notify a change to the listening devices
So instead of saying - "Hey, 'streaming_type' should change from 'wind' to 'temperature'", you would say - "Hey, 'streaming_type' has changed, come read it".
It is not specific to iOS, it is the way BTLE works. So if you want an iPhone to be able to control your device, your application simply needs to setup a BTLE "streaming_type" characteristic, and then update it when the user wants to change the type of data being streamed.
Your BTLE device would then look for this specific "streaming_type" characteristic, and go read it when it receives a update notification.
I am working on developing a bluetooth peripheral to work with my iOS device. I need to make the iOS app receive data whilst it's in background and process that data as it comes. Looking through Apple's CoreBluetooth framework, I can see how the background execution modes can be used. Now to save power, I want the iOS device to only connect to the bluetooth peripheral at a certain time (without need of user interaction). I've looked through Local Notifications on iOS and it has very limited functionality and don't think it provides what I need.
So is there anyway to wake up an app at 6pm and ask the application to start scanning for bluetooth devices? And then execute other code once device is connected? All this without user interaction.
Any suggestions would be appreciated!
Thanks!
You can't really schedule operations to occur at a specific time in iOS (aside from local notification, which as you said isn't what you need).
You can use background fetch mode to periodically allow your app to check for new data. You can set an interval (although this is only a guideline to iOS, not a strict schedule) for how often your app is woken.
When iOS calls your app delegate performFetchWithCompletionHandler method you can check the current time and decide whether you want to transfer data. If not then you can quickly return UIBackgroundFetchResultNoData. If you do get new data then you can retrieve it before returning UIBackgroundFetchResultNewData
I'm writing a suite of Bluetooth Low-Energy app for iOS 7.
When the app launches, there's a fair chance the peripheral I'm interested in is still connected to the iOS device, and to avoid scanning for the peripheral it would be great to connect immediately. retrieveConnectedPeripheralsWithServices: looks perfect for this, and indeed seems to work as advertised: I get a list of CBPeripherals which are connected to the device via some backgrounded app.
So far so good, but here's the issue:
There's information in the AdvertisementData which I want, but I don't know how to get the AdvertisementData when going this route.
As far as I can see, advertisementData is only available as a result of scanning.
So my question is this:
* Given a CBPeripheral returned by retrieveConnectedPeripheralsWithServices:, how can I get the associated advertisementData for that peripheral ?
One workaround would take advantage of the fact that the device was likely connected to another of the apps in my own suite, so I could persist the advertisement data myself in storage shared between the apps, but this is neither clean nor ideal, because there's a chance the device was connected to someone else's app, and so I'd have no insight into the advertisement data in that scenario, and would need to resort to a scan.
Unfortunately, the advertisement data is available only if you scan. It is not possible to retrieve it from Core Bluetooth or any other framework in any other way. You should revise your design if the advertisement is so important and rather go along the scanning route.
Hello I do hope someone can help me with this question as i thought it would be easy at first!
I'm a studying EE student who is not that good with code but trying!
Let me tell you my goal at the end of this.....
I would like to be able to open an app on the iPhone and then execute a bit of code to send a message, all via Bluetooth.
I would like to be able to pair this small Bluetooth device to the iPhone only once and be able for it to be in sleep mode (500 nano amps :D awesome) and when I turn it on (via a small switch) it will open an app and send that message. (the app is already done, you just have to press a button on the app in order to send the message, that's why I would like to use a Bluetooth device so you don't have to have the app open at all times!)
Sorry for the long paragraph but I need help! I have the Bluegiga BLE113 dev kit and im overwhelmed with all the information they give you! But I don't see anywhere where I connect to the iPhone and do what I want to do.
Has anyone done this before, can you steer me in the right direction?
As long as the person downloading the app has previously opened the app and they've agreed to backgrounding capabilities, then yes you can send the message in the background (if already connected). However, you cannot force your app into the foreground on a non-jailbroken iOS device.
Check out the BLE Transfer App sample code to get you started.
I guess what you need is:
the periperal implements the peripheral role
the app implements the central role
the app is trying to connect to the peripheral continuously (connectPeripheral:options:)
the peripheral wakes up on trigger and the phone connection request completes
the peripheral signals to the central using a characteristic change notification
the app receives the notification and executes the business functionality of your desire
the peripheral goes to sleep again
the app receives the disconnect event and starts a connectPeripheral:options: immediately
the app should utilize the new restoration feature of Core Bluetooth (watch the WWDC 2013 session 703 video)
This is just an outline and you need to know lots of small things to get it right. I suggest you try to go ahead and implement piece by piece and if you get stuck, ask a new questions. As #tdevoy suggested, the BTLE Transfer App is a good starting point. The Heart Rate Monitor is also a good source of info (OSX API is the same as the iOS).
I want to advertise a single id lets say "stackoverflow1" on a ble device. So people close to the sensor can get this message (welcome to wwdc2012) as popups on the iPhone. That's it! meaning that there is no update on the value or anything else in other words I just want to know which room I came in. In another room there's another sensor adversing "stackoverflow2".
Now the question is, should I put the rooms' sensor (advertiser) as Peripherals and visitors' iPhones as Centrals?
If your answer is yes, can I send this Id in advertising packet? i.e. can I skip connection to the room's peripheral? Please guide me a little but on this
Thanks
Yes, the iPhones should be centrals and the in-room device should be a peripheral. It's perfectly fine to put enough data in the advertisement that the iOS app can do something useful after simply seeing the peripheral advertised without actually connecting to it. That way, multiple centrals/phones can detect proximity at once without a single phone tying up an exclusive connection to the device. Instead of specifying the room in the service name, you should be able to put it in the advertisement data for the device, giving them all the same service name. That way the iOS app doesn't need to know the completely list of rooms (i.e. services) in advance and they can be added to without changing the app.
In short, the gist of what you described should work fine, and seems like a sound approach to me.
You can include information in the advertisement from the peripheral as "Manufacturer Specific" data. Then the iOS application can get it from the advertisement data dictionary using the CBAdvertisementDataManufacturerDataKey.