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).
Related
Is it possible to create an app where the message is automatically sent from one device to another when both the devices are in the same geo-location in predefined range or in the wireless points like Bluetooth?
I think there must be some way to do this. Please let me know if you have any idea about the same.
In peer-peer connection, It is not possible. When the user terminates the app everything goes with it.
But if you connect it with server, you could try to implement the behavior you are looking for with a push notification with content available, which gives you some time awake to download content in the background.
I'm working on a device that keeps count when a door is closed. What I'd like to do is when I walk through the door, my iPhone automatically syncs the data on the device and sends that count to the server (via iPhone) without me opening the app or having it in the background. Is this possible, if so how?
Here's a diagram of what I'm thinking:
Door closes -> BLE notifies iPhone -> BLE sends count to iPhone ->
iPhone sends that value to server
All without the user (me) touching my device or opening the installed iOS application.
Your app has to be running in the background to do something, but that is OK, because Core Bluetooth background mode will take care of that for you.
First, you need to select "Uses Bluetooth accessories" background mode in your project.
Now, your program flow will be something like this:
Your user runs your app which scans for available doors and displays them to the user
Your user selects a door that they want to connect to
You save the identifier of the selected peripheral somewhere like NSUserDefaults
You connect to the peripheral
Once you get a call to the didConnectPeripheral delegate method you can read the count and update your server once you get the value
The user can now suspend your app and do something else
Eventually the peripheral will go out of range and you will get a call to didDisconnectPeripheral. In this method you immediately re-issue the connect to the peripheral.
Since you have Core Bluetooth background mode, when the peripheral is eventually seen again you will get another call to didConnectPeripheral in the background, and you can proceed as per step 5 (In this case your app is already in the background so it will just go back to suspended state after you have read the data without the user doing anything).
You update the server in step 5. This step executes regardless of whether the app is in the foreground or background. The user doesn't need to open your app.
Now eventually iOS may remove your app from the suspended state, say due to memory pressure. In order to still be able to connect to the peripheral when it is seen you need to opt in to state restoration as described in the Core Bluetooth Programming Guide
If you are up for building your own circuit board and Bluetooth LE firmware, this is pretty straightforward:
Add a contact switch that sends a voltage level change to the circuit board whenever the door opens.
Increment a counter on the microcontroller when the level changes.
Write firmware that advertises an iBeacon packet with the counter as the least significant part of the iBeacon identifier (32 bit major and minor).
A phone can then pick up this counter by using CoreLocation APIs to both monitor for the beacon (for fast background wakeups) and range for it (to read the specific identifier), then sending the counter value to the server based on the identifier read.
The advantage of using CoreLocation instead of CoreBluetooth as #paulw11 suggests in his very good answer is faster background wakeups of the app, allowing an app to reliably read the counter in the background. With CoreBluetooth, this background wakeup can be much slower, and door open events are more likely to be missed.
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.
We were looking for a few roles regarding the Bluetooth LE in iOS, but we could not find them. I have a few questions for anyone who is already using it:
I have read here that there is the ability to listen in the background for the signals, is that right? if so, can i get a signal and open that app from background ?
The other way, can my app run in the background and at some point (lets say when the app gets a notification from alarm) send LE signal without even open the app ?
(Its reasonable that yes, because the iPhone DOES call delegate function, that i can write a LE into it, isn't it?)
Does LE Bluetooth control any iPhone operation(s) outside the relevant app?
Does the Apple docs has some kind of ordered roles for the LE?
Yes. But you can't bring the app to the foreground. You can do some background processing and post a local notification.
Not from an alarm, because the alarm would notify the user, not the app. Possibly from a push notification but that would be a bit weird.
Depends. iPhone can act as Central and Peripheral so it could.
? (You mean Central and Peripheral roles?).
I've got an iPhone, I've got a bluetooth low energy (aka Bluetooth 4.o) device. The two have connected in the past. But now they're apart. Something happened, words were said that couldn't be taken back, and now they've disconnected.
Now they're in the same room again. The BTLE device wants to connect again. It doesn't want to wait for the iPhone to call it. It's taking the initiative. It wants to talk to the iPhone, and get that app they used to share launched again.
How do I set up the iPhone code to support this?
(Wow, corny.)
You have to leave the app connecting to the device, so when the device becomes available the app will connect to it (so long as the app is alive). Just call [centralManager connectPeripheral] on the CMPeripheral, so the phone will keep listening for the device and connect immediately when it sees it. That doesn't time out, so you can just leave it running forever.
If no app is to connect to the peripheral, there's nothing the peripheral can do to change that.
This is a little late, but here's what I would do to accomplish this:
When your device wants to connect, have it advertise a special service.
Assuming the phone is already scanning for devices, it will see the service and you can auto-connect to it.
Now you can have the periphal trigger whatever you like on the central by updating a characteristic, etc.
Of course, this relies on the phone scanning at the time you need the action to trigger, but that is the nature of the beast.