We are using CC2540 BLE Chip as peripheral and an iOS 7.0.4 iPhone is playing central role.
We change the peripheral name, but this change is only shown when we disconnect from iOS device and reconnect.
It works fine in Android using this code to change peripheral name in response data:
GAPRole_SetParameter( GAPROLE_SCAN_RSP_DATA, sizeof ( deviceName ), deviceName );
We are using this code to change the peripheral name of GAP layer in iOS:
GGS_SetParameter( GGS_DEVICE_NAME_ATT, GAP_DEVICE_NAME_LEN, attDeviceName );
Is there any way to change peripheral name so that no reconnection is needed?
For me the problem is in the iOS App code.
The basic order of calls to connect in iOS to BLE is:
centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil
options: nil];
this last one invokes:
- (void) centralManagerDidUpdateState:(CBCentralManager *)central
then if central.state is CBCentralManagerStatePoweredOn you can:
[centralManager scanForPeripheralsWithServices:nil
options:nil];
this last one invokes:
- (void) centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
Apple here recommends: "You must retain a local copy of the peripheral if any command is to be performed on it."
That means you should create a property for your CBPeripheral like:
self.myPeripheral = peripheral;
It is here where you have a peripheral.name or self.myPeripheral.name
If you don't call again in your code: [centralManager scanForPeripheralsWithServices:nil options:nil]; what you have is the information retrieved the first time. You should make the call again if you want to refresh the name. Maybe with a timer.
Hope that helps.
EDIT
Check: Core Bluetooth Programming Guide: Performing Common Central Role Tasks
you can get the local name from advertisementData. There is the solution: Incorrect BLE Peripheral Name with iOS
And on Apple Developer Forums, here is the detail of CBPeripheral name property.
Related
IOS application is communicating with BLE peripheral using Core-Bluetooth framework. The app has registered for glucose characteristic and is receiving data from the peripheral after every one minute.
It is being observed that, when the application is in idle state there is no disconnection from the BLE peripheral whereas if I navigate between the ViewControllers present in the application then there happens to be continuous disconnection with the BLE peripheral.
The connection parameters set are within the given range as mentioned in Apple's Core-Bluetooth programming guide. Any ideas why the connection keeps on getting disconnecting?
I had also used the BTLE Transfer Source Code present in apple developer site. And had replaced the Transfer service UUID with Glucose service UUID. I had tested this on iPhone 6 with iOS version 8.3. I am still facing the same issue of disconnection.
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI {
if (self.discoveredPeripheral != peripheral) {
self.discoveredPeripheral = peripheral;
[self.centralManager connectPeripheral:peripheral options:nil];
}
}
-(void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {
[self.centralManager stopScan];
[self.data setLength:0];
peripheral.delegate = self;
[peripheral discoverServices:#[[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID]]];
}
check you don't explicitly use weak properties to manage your peripherals (by default types are strong), check this issue.
However without any piece of code all I can suggest is to grab a BLE packet sniffer and see who, when and therefore why it sends the disconnection command. In this process beware about the channel hopping, you have 1/3 of chances to capture the channel with the sniffer so just retry until you see the data flow on the screen. If not now, it's always welcome to have a device like that if you will regularly work with Bluetooth Low Energy.
// method called whenever you have successfully connected to the BLE peripheral
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
self.myPeripheral = peripheral;
self.myPeripheral.delegate = self;
NSString *connected = [NSString stringWithFormat:#"Connected: %#", peripheral.state == CBPeripheralStateConnected ? #"YES" : #"NO"];
NSLog(#"%#", connected);
}
Put this method,
Note: It is a good practice to assign your discovered peripheral to a retained CBPeripheral into centralManager: didConnectPeripheral
//this one line code stops disconnecting device automatically.
[[Manager sharedManager].connected_PeripheralDevice discoverServices:nil];
I want to reconnect to BLE device after device is moved out/terminated by user or system/reboted in background mode.
I know that it's possible : - see this question with description
Question - How can i setup centralManager for automatically reconnect to peripheral in background mode if app was terminated? Can someone describe step-by-step how it can be done?
Few word about current implementation:
I create centralManager with options like:
self.centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil options:#{
CBCentralManagerOptionRestoreIdentifierKey: #"myCentralManagerIdentifier",
CBCentralManagerRestoredStatePeripheralsKey : #YES,
CBCentralManagerRestoredStateScanServicesKey : #YES,
CBCentralManagerRestoredStateScanOptionsKey : #YES
}];
After that i start to scan for BLE device
[self.centralManager scanForPeripheralsWithServices:[self discoverableCharacteristics] options:nil];
in - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI i connect to peripheral:
NSString *localName = [advertisementData objectForKey:CBAdvertisementDataLocalNameKey];
[self.centralManager stopScan];
peripheral.delegate = self;
[self.centralManager connectPeripheral:peripheral options: #{
CBConnectPeripheralOptionNotifyOnNotificationKey : #YES
}];
After that i can discover services and characteristics - all looks like ok. When i discover characteristic and read/write data i cancelPeripheralConnection
in didDisconnect i reconnect to device
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error
{
[central connectPeripheral:peripheral options:nil];
}
i also implement centralManager:willRestoreState: like:
NSArray *peripherals = dict[CBCentralManagerRestoredStatePeripheralsKey];
for (CBPeripheral *peripheral in peripherals) {
[central connectPeripheral:peripheral options:nil];
peripheral.delegate = nil;
}
In plist. added required key App communicates using CoreBluetooth.
Currently if i connected to device and terminate it - it relaunch automatically and connect to device - all it's ok, but if it's terminated again - nothing is happening.
Also if i moved out from peripheral and that come back - nothing happened.
Update
regarding point 5 - my fall - should use this key with connectPeripheral
in WillRestoreState:
NSArray *peripherals = dict[CBCentralManagerRestoredStatePeripheralsKey];
if (!peripherals.count) {
peripherals = [central retrievePeripheralsWithIdentifiers:[self discoverableCharacteristics]];
}
if (peripherals.count) {
for (CBPeripheral *peripheral in peripherals) {
[central connectPeripheral:peripheral options:#{
CBCentralManagerRestoredStatePeripheralsKey : #YES,
CBCentralManagerRestoredStateScanServicesKey : #YES,
CBCentralManagerRestoredStateScanOptionsKey : #YES
}];
}
} else {
[self startScanning];
}
Current result - app will relaunched if it not swiped out from tray. I use my mac as a peripheral, so some times when i not launch app that make role of peripheral central can connect to mac itself not to required service.
Another question - are it's good option to reconnect to peripheral while lost connection for keeping connection like:
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(nullable NSError *)error
{
[central connectPeripheral:peripheral options:#{
CBCentralManagerRestoredStatePeripheralsKey : #YES,
CBCentralManagerRestoredStateScanServicesKey : #YES,
CBCentralManagerRestoredStateScanOptionsKey : #YES
}];
}
Also try to change notify characteristic on peripheral and read it on device. If all done in foreground - all works perfect, but in case connection was done in background some times didUpdateValueForCharacteristic not called at all, but didUpdateNotificationStateForCharacteristic is called with no error - this mean (i think) that something was done wrong by my side. Maybe u can advice where problem can be
And one more question - is there is some restriction in writing data to characteristics? because in apple sample it's setuped to 20 bytes.
First off I wanna start by saying that I have been working with CoreBluetooth for about two years now and from what I have noticed CoreBluetooth State Preservation and Restoration does not work reliably at all. You can get it working sort of "ok", but you will never get it to reconnect reliably unless Apple fixes it some day.
Having said that, I want to note a few things on your setup.
1) In centralManager:willRestoreState: you can only retrieve peripherals that has done any communication while the app was terminated. This means that you should also implement centralManagerDidUpdateState: and if the state is CBCentralManagerStatePoweredOn then you can use the retrievePeripheralsWithIdentifiers: method to retrieve the other peripheral and reset their delegate as well. This of course means that you have to stor the peripheral identifiers somewhere in your app somewhere. Also remember to reset pending connections here as well.
2) You set the delegate to nil in centralManager:willRestoreState:! So even if it does connect then you will not know about it i:P
3) Your app will only get relaunched if the app was terminated by the system. It will not get relaunched if you manually swipe-kill it from the application list. Neither will it get relaunched if the device is rebooted, unfortunately.
4) The CBConnectPeripheralOptionNotifyOnConnectionKey is not necessary when using the bluetooth-central background mode and is just annoying for a user so I would not use it.
5) CBCentralManagerRestoredStatePeripheralsKey, CBCentralManagerRestoredStateScanServicesKey, CBCentralManagerRestoredStateScanOptionsKey are not valid initialisation options so I don’t get why you are using those..
5) If the bluetooth switches state while the app is terminated then all pending connections will be lost and you will not be relaunched to know about it. This on its own effectively means that State Restoration is rather useless.
Anyhow, I am sad to say it, but if you are developing an app that must rely on the peripheral being reconnected in the background then I wold not recommend doing it. You will be frustrated. I could probably write an essay about all the bugs in Core Bluetooth that Apple does not want to fix. Even more frightening is that you can pretty easily ruin the bluetooth connectivity globally on the device from one single app so that no app can use bluetooth until the device is rebooted. This is pretty bad since it goes against Apples own Sandboxing principle.
If you need any more help, just let me know!
/A
I want use CoreBluetooth.framework in IOS8 to achieve data transfer, i did discover peripheral in the follow method and try connect the peripheral.
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
NSLog(#"Discover name : %#", peripheral.name);
[self.centralManager connectPeripheral:peripheral options:nil];
}
But it did not call the delegate methods didFailToConnectPeripheral or didConnectPeripheral , I waner what's wrong with it, is the code error or IOS8 need some extra things ? How to deal it, thank in advance!
here is my code in github ,I write a Program to be server and another be Central.
#Sj comment solved it for me, copying it into an answer in case someone will miss it:
Did u tried storing the peripheral object in an ivar and then connect to it? ie self.discoveredPeripheral = peripheral; [self.centralManager connectPeripheral:self.discoveredPeripheral options:nil];
I am using TemperatureSensor iOS sample app which didDiscoverPeripheral did not called. By reference the flow of Heart Rate Monitor Mac sample app. Please make sure the run sequence of code is:
1. centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:dispatch_get_main_queue()];
2. - (void) centralManagerDidUpdateState:(CBCentralManager *)central
3. [centralManager scanForPeripheralsWithServices:...
- (void) centralManager:(CBCentralManager *)central didDiscoverPeripheral:... will be called afterwards.
Call the connect method only once and wait for the connection delegate response. The above code which you posted will call the connect method more often (when ever it discover the peripheral)
if(!self.detectedBLE){
[self.centralManager stopScan];
self.detectedBLE = peripheral;
[self.centralManager connectPeripheral:self.detectedBLE options:nil];
}
I have one Bluetooth LE device, I need to scan it only, that I have done with Core Bluetooth Framework in iPhone SDk.
Below is sample code,
manager is object of CBCenterManager which writes in the init method:
manager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
scanning process:
- (void)startScan
{
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:FALSE], CBCentralManagerScanOptionAllowDuplicatesKey, nil];
manager.delegate = self;
[manager scanForPeripheralsWithServices:nil options:options];
}
Now I got that device in delegate methods,
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
NSLog(#"Did discover peripheral. peripheral: %# rssi: %#, UUID: %# advertisementData: %# ", peripheral, RSSI, peripheral.UUID, advertisementData);
}
**Here I have write only few lines of code,
This is not enough data for me to show in interface. Because peripheral.UUID is unique for each device, if I change device to discover BLE, it will be changed.
So I want unique address of Bluetooth LE device which I got same in every iOS devices.
Like peripheral.UUID is 1FE639DB-3C54-B5A8-74A4-3D9FBFCAD074
I had discover same thing in android got address like C8:4D:93:78:98:AE this.
and its unique for all android devices,
So I am searching for the same thing in iPhone SDK.
Is it possible to get same unique address of Bluetooth LE in iPhone SDK?
Thanks for your time to read questions.
When I use:
CBUUID * uuid = [CBUUID UUIDWithString:#"1800"]; // GAP
DEBUG_LOG(#"CBUUID: %#",uuid); // CBUUID: Generic Access Profile
_centralMan = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
[_centralMan scanForPeripheralsWithServices:[NSArray arrayWithObject:uuid]
options:nil];
I cannot find my peripheral, but when I use:
_centralMan = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
[_centralMan scanForPeripheralsWithServices:nil
options:nil];
…it shows up immediately.
When I connect, I am able to discover/read/write to all the services I am expecting. My understanding is that GAP makes this possible. I have also tried CBUUID's for other services that I know are running (specifically "1804", TX power service), to no avail; the scan never discovers anything.
Even though the services are running (I can communicate w/ them upon connecting), when I scan passing the service UUID array as nil and this delegate method is called...
-(void) centralManager:(CBCentralManager *)central
didDiscoverPeripheral:(CBPeripheral *)peripheral
advertisementData:(NSDictionary *)advertisementData
RSSI:(NSNumber *)RSSI {
DEBUG_LOG(#"Found peripheral w/ UUID: %# RSSI: %# \n AdvData: %#",peripheral.UUID,RSSI,advertisementData);
DEBUG_LOG(#"Services found: %d",peripheral.services.count);
for (CBService * service in peripheral.services) {
DEBUG_LOG(#"Found service: %# w/ UUID %#",service, service.UUID);
}
}
…it always reports "Services found: 0". Should I expect the services array to be populated w/ services found during the scan? (I assume this is at least partially possible, based on scanForPeripheralsWithServices:[NSArray arrayWithObject:uuid]
options:nil.)
Could this be a problem w/ my peripheral's service advertisements? Am I using the API incorrectly? Any guidance is much appreciated! :-)
PS: I'm pretty green w/ Bluetooth.
PPS: I control the source to the peripheral (it's a CC2540DK). So I'd be as likely to believe the problem is there as it is here.
Turns out our peripheral code was not advertising the UUIDs a la this Bluetooth spec.
As soon as we dropped them into the advertising packet, iOS picked them up no sweat.