I am an Android developer, moving over to iOS, so please bear with me regarding the basics of iOS development.
I have the following code:
Here is the .m file:
#import "BlueToothLEManager.h"
#import "Constants.h"
#implementation BlueToothLEManager
#synthesize mBTCentralManager;
-(void)initializeCBCentralManager{
NSLog(#"initializing CBCentral Manager"); <--- This is being logged
mBTCentralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
}
#pragma mark - CBCentralManagerDelegate
// method called whenever you have successfully connected to the BLE peripheral
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
}
// CBCentralManagerDelegate - This is called with the CBPeripheral class as its main input parameter. This contains most of the information there is to know about a BLE peripheral.
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
NSLog(#"Discovered %# at %#", peripheral.name, RSSI);
}
-(void)centralManagerDidUpdateState:(CBCentralManager *)central{
NSLog(#"Start scan"); <---- This is NOT being logged.
if(central.state != CBCentralManagerStatePoweredOn){
return;
}
if(central.state == CBCentralManagerStatePoweredOn){
NSLog(#"Scanning for BTLE device");
[mBTCentralManager scanForPeripheralsWithServices:#[[CBUUID UUIDWithString:DEVICE_NAME]] options:#{ CBCentralManagerScanOptionAllowDuplicatesKey : #YES }];
}
}
#end
Here is the .h file:
#import <Foundation/Foundation.h>
#import CoreBluetooth;
#interface BlueToothLEManager : NSObject < CBCentralManagerDelegate, CBPeripheralDelegate>{
CBCentralManager *mBTCentralManager;
}
#property (strong, retain) CBCentralManager *mBTCentralManager;
-(void) initializeCBCentralManager;
#end
When I call initializeCBCentralManager everything appears to work, but for some reason the centralManagerDidUpdateState method isn't being called. Can someone tell me what I'm doing wrong?
You should clean up your property definition as your iVar is getting mixed up with your property. If you declare a property you don't need to declare an iVar. You also don't need #synthesize unless you want a specific name for the backing variable. If you use the self. notation then you can be sure that you are referring to the property and not an iVar.
Your .h file should be -
#import CoreBluetooth;
#interface BlueToothLEManager : NSObject < CBCentralManagerDelegate, CBPeripheralDelegate>
#property (strong, retain) CBCentralManager *mBTCentralManager;
-(void) initializeCBCentralManager;
#end
Then your .m file will be
#import "BlueToothLEManager.h"
#import "Constants.h"
#implementation BlueToothLEManager
-(void)initializeCBCentralManager{
NSLog(#"initializing CBCentral Manager");
self.mBTCentralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
}
#pragma mark - CBCentralManagerDelegate
// method called whenever you have successfully connected to the BLE peripheral
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
}
// CBCentralManagerDelegate - This is called with the CBPeripheral class as its main input parameter. This contains most of the information there is to know about a BLE peripheral.
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
NSLog(#"Discovered %# at %#", peripheral.name, RSSI);
}
-(void)centralManagerDidUpdateState:(CBCentralManager *)central{
NSLog(#"Start scan");
if(central.state == CBCentralManagerStatePoweredOn){
NSLog(#"Scanning for BTLE device");
[central scanForPeripheralsWithServices:#[[CBUUID UUIDWithString:DEVICE_NAME]] options:#{ CBCentralManagerScanOptionAllowDuplicatesKey : #YES }];
}
}
#end
I have tested this and it works
Related
Edit: Now tested on my actual iphone, and I still get the same crash error
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSCFConstantString stringByAppendingString:]: nil argument'
When I ran the debugger, I ran through the debugger with breakpoints, but it did not reach any other function besides the tLog and the didLoad. The message "Bluetooth LE Device Scanner\r\n\r" went through the tLog a few times without before the app crashed because of the invalid argument
Original -
Info: Mac OSX Yosemite; Xcode 6.4; Using Objective C
Right now, I am following the video tutorial on setting up the bluetooth scanner to detect devices powered by bluetooth.
Video Links:
https://www.youtube.com/watch?v=zjr8qLE0sxk
https://www.youtube.com/watch?v=AjBpB4TcI-U (This part is where crash occurs)
I followed the code and understood the basics of core bluetooth framework. However, when running the test under both the iOS simulator and my iPhone, the application crashes at start-up.
The error I get is:
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSCFConstantString stringByAppendingString:]: nil argument' (iOS simulator)
I used the breakpoints that involve tlog and start-up, and that same error is still there because it is stuck printing the same thing.
Is there any fix I should do to get the basic bluetooth scanner running?
EDIT -
The code from the tutorial that I followed:
#import "ViewController.h"
#interface ViewController ()
// Now we need the properties to do various tasks for the device scanner
#property (weak, nonatomic) IBOutlet UITextView *outputTextView;
#property (weak, nonatomic) IBOutlet UISegmentedControl *verbositySelector;
#property (strong, nonatomic) CBCentralManager *centralManager;
#property (strong, nonatomic) CBPeripheral *discoveredPeripheral;
#property BOOL bluetoothOn;
#property (weak, nonatomic) IBOutlet UILabel *valueLabel;
#end
#implementation ViewController
-(bool)verboseMode
{
return (self.verbositySelector.selectedSegmentIndex != 0);
}
-(void)tlog:(NSString*)msg
{
self.outputTextView.text = [#"\r\n\r\n" stringByAppendingString:self.outputTextView.text];
self.outputTextView.text = [msg stringByAppendingString:self.outputTextView.text];
}
-(IBAction)startScan:(id)sender
{
if (!self.bluetoothOn){
[self tlog:#"Bluetooth is OFF"];
return;
}
[self.centralManager scanForPeripheralsWithServices:nil
options:
#{CBCentralManagerScanOptionAllowDuplicatesKey: #NO}];
}
// Standard template items added in by default. DO NOT REMOVE!
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self tlog:#"Bluetooth LE Device Scanner\r\n\r"];
self.bluetoothOn = NO;
self.centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
// Core Bluetooth Tasks
-(void) centralManager:(CBCentralManager *)central
didDiscoverPeripheral:(CBPeripheral *)peripheral
advertisementData:(NSDictionary *)advertisementData
RSSI:(NSNumber *)RSSI
{
[self tlog:[NSString stringWithFormat:#"Discovered %#, RSSI: %#\n",
[advertisementData objectForKey:#"kCBAdvDataLocalName"], RSSI]];
self.discoveredPeripheral = peripheral;
if ([self verboseMode]){
[self.centralManager connectPeripheral:peripheral options:nil];
}
}
-(void) centralManager:(CBCentralManager *)central
didFailToConnectPeripheral:(CBPeripheral *)peripheral
error:(NSError *)error
{
}
-(void) centralManager:(CBCentralManager *)central
didConnectPeripheral:(CBPeripheral *)peripheral
{
}
-(void) peripheral:(CBPeripheral *)peripheral
didDiscoverServices:(NSError *)error
{
}
-(void) peripheral:(CBPeripheral *)peripheral
didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
{
}
-(void) peripheral:(CBPeripheral *)peripheral
didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic
error:(NSError *)error
{
}
-(void) centralManagerDidUpdateState:(CBCentralManager *)central
{
if (central.state != CBCentralManagerStatePoweredOn){
[self tlog:#"Bluetooth OFF"];
self.bluetoothOn = NO;
}
else {
[self tlog:#"Bluetooth ON"];
self.bluetoothOn = YES;
}
}
#end
I have a bluetooth bracelet which connects to my iPhone 5s via Bluetooth; it comes with an App called Zeroner. Now I want to obtain the information from the connected and paired up bracelet without using the App. Here is what I attempted to do:
Setup CBCentralManager
Use retrieveConnectedPeripheralsWithServices: to obtain connected devices
Here is the code:
CBConnectedDevicesVC.h
#import <UIKit/UIKit.h>
#import <CoreBluetooth/CoreBluetooth.h>
#import SERVICE_ID #"FB694B90-F49E-4597-8306-171BBA78F846"
#interface CBConnectedDevicesVC : UIViewController <CBCentralManagerDelegate, CBPeripheralDelegate>
#property (strong, nonatomic) CBCentralManager *centralManager;
#property (strong, nonatomic) CBPeripheral *discoveredPeripheral;
#end
CBConnectedDevicesVC.m
#import "CBConnectedDevicesVC.h"
#implementation CBConnectedDevicesVC
- (void)viewDidLoad {
[super viewDidLoad];
_centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
}
- (void)centralManagerDidUpdateState:(CBCentralManager *)central {
if (central.state != CBCentralManagerStatePoweredOn) {
return;
}
if (central.state == CBCentralManagerStatePoweredOn) {
NSArray* connectedDevices = [_centralManager retrieveConnectedPeripheralsWithServices:#[[CBUUID UUIDWithString:SERVICE_UUID]]];
for (CBUUID *uuid in connectedDevices) {
NSLog(#"Device Found. UUID = %#", uuid);
}
}
}
#end
For the above codes, I have to specify the service ID in SERVICE_UUID, which I don't know what the value of the bracelet is. Is there any alternatives to obtain the information from the connected bracelet?
UPDATE about test result of LightBlue App
After unpaired from Zeroner App and "Forget this Device" in Settings > Bluetooth > choose the device named "Bracelet-0366", LightBlue App discovers the device (finally!).
Here is the result screenshot:
I got several values here, but I'm not sure which values I should use.
Further Test Results:
If I put the UUID (starts with 4EFF) found in LightBlue into SERVICE_ID, no delegate is called with the above codes.
Another piece of code I tried is (obtained from Tut+ tutorial):
NSArray *serviceID;
#implementation CBCentralManagerViewController
- (void)viewDidLoad {
[super viewDidLoad];
serviceID = #[[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID]];
_centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
_data = [[NSMutableData alloc] init];
}
- (void)centralManagerDidUpdateState:(CBCentralManager *)central {
// You should test all scenarios
if (central.state != CBCentralManagerStatePoweredOn) {
return;
}
if (central.state == CBCentralManagerStatePoweredOn) {
// Scan for devices
[_centralManager scanForPeripheralsWithServices:serviceID options:#{ CBCentralManagerScanOptionAllowDuplicatesKey : #YES }];
NSLog(#"Scanning started");
}
}
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI {
NSLog(#"Discovered %# at %#", peripheral.name, RSSI);
if (_discoveredPeripheral != peripheral) {
// Save a local copy of the peripheral, so CoreBluetooth doesn't get rid of it
_discoveredPeripheral = peripheral;
// And connect
NSLog(#"Connecting to peripheral %#", peripheral);
[_centralManager connectPeripheral:peripheral options:nil];
}
}
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error {
NSLog(#"Failed to connect");
[self cleanup];
}
- (void)cleanup {
// See if we are subscribed to a characteristic on the peripheral
if (_discoveredPeripheral.services != nil) {
for (CBService *service in _discoveredPeripheral.services) {
if (service.characteristics != nil) {
for (CBCharacteristic *characteristic in service.characteristics) {
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]]) {
if (characteristic.isNotifying) {
[_discoveredPeripheral setNotifyValue:NO forCharacteristic:characteristic];
return;
}
}
}
}
}
}
[_centralManager cancelPeripheralConnection:_discoveredPeripheral];
}
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {
NSLog(#"Connected");
[_centralManager stopScan];
NSLog(#"Scanning stopped");
[_data setLength:0];
peripheral.delegate = self;
[peripheral discoverServices:serviceID];
}
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error {
if (error) {
[self cleanup];
return;
}
for (CBService *service in peripheral.services) {
[peripheral discoverCharacteristics:#[[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]] forService:service];
}
// Discover other characteristics
}
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error {
if (error) {
[self cleanup];
return;
}
for (CBCharacteristic *characteristic in service.characteristics) {
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]]) {
[peripheral setNotifyValue:YES forCharacteristic:characteristic];
}
}
}
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
if (error) {
NSLog(#"Error");
return;
}
NSString *stringFromData = [[NSString alloc] initWithData:characteristic.value encoding:NSUTF8StringEncoding];
// Have we got everything we need?
if ([stringFromData isEqualToString:#"EOM"]) {
[_textview setText:[[NSString alloc] initWithData:self.data encoding:NSUTF8StringEncoding]];
[peripheral setNotifyValue:NO forCharacteristic:characteristic];
[_centralManager cancelPeripheralConnection:peripheral];
}
[_data appendData:characteristic.value];
}
- (void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
if (![characteristic.UUID isEqual:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]]) {
return;
}
if (characteristic.isNotifying) {
NSLog(#"Notification began on %#", characteristic);
} else {
// Notification has stopped
[_centralManager cancelPeripheralConnection:peripheral];
}
}
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error {
_discoveredPeripheral = nil;
//
[_centralManager scanForPeripheralsWithServices:serviceID options:#{ CBCentralManagerScanOptionAllowDuplicatesKey : #YES }];
}
With the above code, there are 2 constants defined TRANSFER_SERVICE_ID and TRANSFER_CHARACTERISTIC_ID. From the tutorial, the TRANSFER_SERVICE_ID should be set to the one starts with 4EFF and the TRANSFER_CHARACTERISTIC_ID should be set to 0xFF20 or FF20. However, this piece of code does not detect the bracelet at all, even though the bracelet is unpaired & disconnected. What did I miss this time?
Don't worry about the UUID that starts with 4EFF - this is the UUID of the device and will be different for each one.
The service id is FF20 - You can use this in scanForPeripheralsWithServices - this is SERVICE_ID in your code above.
Then you have two characteristics- FF21 and FF22
You can write to FF21 using the writeValue method on your CBPeripheral instance.
With FF22 that you can subscribe to notifications using the setNotify CBPeripheral method. You will then get a call to the didUpdateValueForCharacteristic CBPeripheralDelegate method whenever the device changes the value.
There are 2 types of bluetooth devices you can work with:
BLE devices - no need (often can't) to pair them with iPhone
"standard" bluetooth devices - you need to pair them with iPhone before use
Those two types are managed independently - from the way you described it I expect your bracelet to fall into "standard" category, and CoreBluetooth can only be used for BLE.
For working with already paired external accessories you should use ExternalAccessory framework
My app won't detect peripherals. Im using light blue to simulate a bluetooth low energy peripheral and my app just won't sense it. I even installed light blue on two devices to make sure it was generating a peripheral signal properly and it is. Any suggestions? My labels are updating and the NSLog is showing that the scanning is starting.
Thanks in advance.
#import <UIKit/UIKit.h>
#import <CoreBluetooth/CoreBluetooth.h>
#interface ViewController : UIViewController
#property (weak, nonatomic) IBOutlet UITextField *navDestination;
#end
#import "ViewController.h"
#implementation ViewController
- (IBAction)connect:(id)sender {
}
- (IBAction)navDestination:(id)sender {
NSString *destinationText = self.navDestination.text;
}
- (void)viewDidLoad {
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface BlueToothViewController : UIViewController
#property (strong, nonatomic) CBCentralManager *centralManager;
#property (strong, nonatomic) CBPeripheral *discoveredPerepheral;
#property (strong, nonatomic) NSMutableData *data;
#property (strong, nonatomic) IBOutlet UITextView *textview;
#property (weak, nonatomic) IBOutlet UILabel *charLabel;
#property (weak, nonatomic) IBOutlet UILabel *isConnected;
#property (weak, nonatomic) IBOutlet UILabel *myPeripherals;
#property (weak, nonatomic) IBOutlet UILabel *aLabel;
- (void)centralManagerDidUpdateState:(CBCentralManager *)central;
- (void)centralManger:(CBCentralManager *)central didDiscoverPeripheral: (CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI;
-(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;
-(void)cleanup;
-(void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error;
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error;
-(void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;
-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error;
-(void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error;
#end
#interface BlueToothViewController ()
#end
#implementation BlueToothViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad {
_centralManager = [[CBCentralManager alloc]initWithDelegate:self queue:nil options:nil];
_data = [[NSMutableData alloc]init];
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
[_centralManager stopScan];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)centralManagerDidUpdateState:(CBCentralManager *)central {
//you should test all scenarios
if (central.state == CBCentralManagerStateUnknown) {
self.aLabel.text = #"I dont do anything because my state is unknown.";
return;
}
if (central.state == CBCentralManagerStatePoweredOn) {
//scan for devices
[_centralManager scanForPeripheralsWithServices:nil options:#{ CBCentralManagerScanOptionAllowDuplicatesKey : #YES }];
NSLog(#"Scanning Started");
}
if (central.state == CBCentralManagerStateResetting) {
self.aLabel.text = #"I dont do anything because my state is resetting.";
return;
}
if (central.state == CBCentralManagerStateUnsupported) {
self.aLabel.text = #"I dont do anything because my state is unsupported.";
return;
}
if (central.state == CBCentralManagerStateUnauthorized) {
self.aLabel.text = #"I dont do anything because my state is unauthorized.";
return;
}
if (central.state == CBCentralManagerStatePoweredOff) {
self.aLabel.text = #"I dont do anything because my state is powered off.";
return;
}
}
- (void)centralManger:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI {
NSLog(#"Discovered %# at %#", peripheral.name, RSSI);
self.myPeripherals.text = [NSString stringWithFormat:#"%#%#",peripheral.name, RSSI];
if (_discoveredPerepheral != peripheral) {
//save a copy of the peripheral
_discoveredPerepheral = peripheral;
//and connect
NSLog(#"Connecting to peripheral %#", peripheral);
[_centralManager connectPeripheral:peripheral options:nil];
self.aLabel.text = [NSString stringWithFormat:#"%#", peripheral];
}
}
-(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error {
NSLog(#"Failed to connect");
[self cleanup];
}
-(void)cleanup {
//see if we are subscribed to a characteristic on the peripheral
if (_discoveredPerepheral.services != nil) {
for (CBService *service in _discoveredPerepheral.services) {
if (service.characteristics != nil) {
for (CBCharacteristic *characteristic in service.characteristics) {
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:#"508EFF8E-F541-57EF-BD82-B0B4EC504CA9"]]) {
if (characteristic.isNotifying) {
[_discoveredPerepheral setNotifyValue:NO forCharacteristic:characteristic];
return;
}
}
}
}
}
}
[_centralManager cancelPeripheralConnection:_discoveredPerepheral];
}
-(void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {
NSLog(#"Connected");
[_centralManager stopScan];
NSLog(#"Scanning stopped");
self.isConnected.text = [NSString stringWithFormat:#"Connected"];
[_data setLength:0];
peripheral.delegate = self;
[peripheral discoverServices:nil];
}
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error {
if (error) { [self cleanup];
return;
}
for (CBService *service in peripheral.services) {
[peripheral discoverCharacteristics:nil forService:service];
}
//discover other characteristics
}
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error {
if (error) { [self cleanup];
return;
}
for (CBCharacteristic *characteristic in service.characteristics) {
[peripheral setNotifyValue:YES forCharacteristic:characteristic];
}
}
-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
if (error) { NSLog(#"Error");
return;
}
NSString *stringFromData = [[NSString alloc]initWithData:characteristic.value encoding:NSUTF8StringEncoding];
self.charLabel.text = [NSString stringWithFormat:#"%#", stringFromData];
//Have we got everything we need?
if ([stringFromData isEqualToString:#"EOM"]) {
[_textview setText:[[NSString alloc]initWithData:self.data encoding:NSUTF8StringEncoding]];
[peripheral setNotifyValue:NO forCharacteristic:characteristic];
[_centralManager cancelPeripheralConnection:peripheral];
}
}
-(void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
if ([characteristic.UUID isEqual:nil]) {
return;
}
if (characteristic.isNotifying) {
NSLog(#"Notification began on %#", characteristic);
}
else {
[_centralManager cancelPeripheralConnection:peripheral];
}
}
-(void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error {
_discoveredPerepheral = nil;
self.isConnected.text = [NSString stringWithFormat:#"Connecting..."];
[_centralManager scanForPeripheralsWithServices:nil options:#{ CBCentralManagerScanOptionAllowDuplicatesKey : #YES}];
}
#end
Looks like you aren't declaring that you implement the CBCentralManagerDelegate protocol. Change your BlueToothViewController interface to add the CBCentralManagerDelegate.
#interface BlueToothViewController () <CBCentralManagerDelegate>
I have one Bluetooth device with some service. I'm able to connect my app with this device, and I'm able to see all services of my BT device, but I would like to see what is the name of the various services, for example:
Device Information
UUID : 0x180A
I think it is possible because some universal app allow you to view it.
Follow the Apple tutorial, it is very clear there :
Starting with:
#interface ViewController () <CBCentralManagerDelegate, CBPeripheralDelegate>
//centralManager:willRestoreState:
#property (nonatomic,strong) CBPeripheral *connectingPeripheral;
#end
#implementation ViewController
{
CBCentralManager *centralManager;
}
Then:
- (void)viewDidLoad
{
[super viewDidLoad];
//Starting Up a Central Manager
centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil
options: nil];
}
initWithDelegate: queue: options: calls through CBCentralManagerDelegate:
- (void) centralManagerDidUpdateState:(CBCentralManager *)central
{
[centralManager scanForPeripheralsWithServices:nil //Services
options:nil];
}
scanForPeripheralsWithServices: options: calls through CBCentralManagerDelegate:
- (void) centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
self.connectingPeripheral = peripheral;
//You should connect to your BLE Device with:
[centralManager connectPeripheral:self.connectingPeripheral
options: nil]
}
The response of this call is through the delegate connectPeripheral: options:
Then:
- (void) centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
//(...)
[peripheral discoverServices:nil]; // Service
}
discoverServices: calls peripheral: didDiscoverServices: from CBPeripheralDelegate
- (void) peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error
{
for (CBService *service in peripheral.services)
{
NSLog(#"Discovered service %#", service);
NSLog(#"Discovered service %#", service.UUID);
}
}
There you have what you want!
It is important to know the properties of a CBService:
Identifying a Service
UUID property
peripheral property
isPrimary property
Accessing Service Data
characteristics property
includedServices property
I have an iOS device (iPod Touch 5G) acting as a CBCentralManager, and Bluno acting as a CBPeripheralManager. When I attempt to connect to the peripheral with the central it appears to connect for a second or two then disconnects. I can see a LED on the Bluno light up for a second or two then dim down. I know there isn't a problem with the Bluno because I can use the LightBlue app on the iPod Touch to connect to the peripheral. So the problem probably lies somewhere in my code.
As of right now, I am getting the following message when I status syslog,
CoreBluetooth[WARNING] <CBCentralManager: 0x16e77470> is disabling duplicate filtering, but is using the default queue (main thread) for delegate events
Not sure if that is related to the connect / disconnect problem.
The code I have constructed is as follows,
Services.h
#define BLUNO_TRANSFER_SERVICE_UUID #"0xDFB0"
#define BLUNO_TRANSFER_CHARACTERISTIC_UUID #"0xDFB2"
ViewControllerDev2.h
#import <Foundation/Foundation.h>
#import <CoreBluetooth/CoreBluetooth.h>
#import <QuartzCore/QuartzCore.h>
#import "SERVICES.h"
#interface ViewControllerDev2 : UIViewController <CBCentralManagerDelegate, CBPeripheralDelegate, UITextViewDelegate> {
}
#property (weak, nonatomic) IBOutlet UIBarButtonItem *btnDone;
// Core Bluetooth Peripheral stuff
#property (strong, nonatomic) CBCentralManager *centralManager;
#property (strong, nonatomic) CBPeripheral *discoveredPeripheral;
#property (strong, nonatomic) NSMutableData *data;
#property (strong, nonatomic) IBOutlet UITextView *textView;
#property (weak, nonatomic) IBOutlet UIButton *btnSend;
- (IBAction)dismissScene:(id)sender;
- (IBAction)sendBTData:(id)sender;
#end
ViewControllerDev2.m
#import "ViewControllerDev2.h"
#implementation ViewControllerDev2
- (void)viewDidLoad
{
[super viewDidLoad];
_centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil options:nil]; // options:nil is an iOS 7 feature
_data = [[NSMutableData alloc] init];
}
- (void)viewDidUnload {
[self setBtnDone:nil];
[super viewDidUnload];
}
- (IBAction)sendBTData:(id)sender {
//[self sendData];
}
- (IBAction)dismissScene:(id)sender {
[self dismissViewControllerAnimated:YES completion:nil];
[_centralManager stopScan];
}
- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
// You should test all scenarios
if (central.state != CBCentralManagerStatePoweredOn) {
return;
}
if (central.state == CBCentralManagerStatePoweredOn) {
// Scan for devices
[_centralManager scanForPeripheralsWithServices:#[[CBUUID UUIDWithString:BLUNO_TRANSFER_SERVICE_UUID]] options:#{ CBCentralManagerScanOptionAllowDuplicatesKey : #YES }];
NSLog(#"Scanning started");
}
}
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI {
NSLog(#"Discovered %# at %#", peripheral.name, RSSI);
if (_discoveredPeripheral != peripheral) {
// Save a local copy of the peripheral, so CoreBluetooth doesn't get rid of it
_discoveredPeripheral = peripheral;
// And connect
NSLog(#"Connecting to peripheral %#", peripheral);
[_centralManager connectPeripheral:peripheral options:nil];
// then stop scanning for peripherals
[_centralManager stopScan];
NSLog(#"Scanning stopped");
}
}
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error {
NSLog(#"Failed to connect");
[self cleanup];
}
- (void)cleanup {
// See if we are subscribed to a characteristic on the peripheral
if (_discoveredPeripheral.services != nil) {
for (CBService *service in _discoveredPeripheral.services) {
if (service.characteristics != nil) {
for (CBCharacteristic *characteristic in service.characteristics) {
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:BLUNO_TRANSFER_CHARACTERISTIC_UUID]]) {
if (characteristic.isNotifying) {
[_discoveredPeripheral setNotifyValue:NO forCharacteristic:characteristic];
return;
}
}
}
}
}
}
[_centralManager cancelPeripheralConnection:_discoveredPeripheral];
}
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {
NSLog(#"Connected");
[_centralManager stopScan];
NSLog(#"Scanning stopped");
[_data setLength:0];
peripheral.delegate = self;
[peripheral discoverServices:#[[CBUUID UUIDWithString:BLUNO_TRANSFER_SERVICE_UUID]]];
}
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error {
if (error) {
[self cleanup];
return;
}
for (CBService *service in peripheral.services) {
[peripheral discoverCharacteristics:#[[CBUUID UUIDWithString:BLUNO_TRANSFER_CHARACTERISTIC_UUID]] forService:service];
}
// Discover other characteristics
}
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error {
if (error) {
[self cleanup];
return;
}
for (CBCharacteristic *characteristic in service.characteristics) {
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:BLUNO_TRANSFER_CHARACTERISTIC_UUID]]) {
[peripheral setNotifyValue:YES forCharacteristic:characteristic];
}
}
}
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
if (error) {
NSLog(#"Error");
return;
}
NSString *stringFromData = [[NSString alloc] initWithData:characteristic.value encoding:NSUTF8StringEncoding];
// Have we got everything we need?
if ([stringFromData isEqualToString:#"EOM"]) {
//[_textview setText:[[NSString alloc] initWithData:self.data encoding:NSUTF8StringEncoding]];
[peripheral setNotifyValue:NO forCharacteristic:characteristic];
[_centralManager cancelPeripheralConnection:peripheral];
}
[_data appendData:characteristic.value];
}
- (void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
if (![characteristic.UUID isEqual:[CBUUID UUIDWithString:BLUNO_TRANSFER_CHARACTERISTIC_UUID]]) {
return;
}
if (characteristic.isNotifying) {
NSLog(#"Notification began on %#", characteristic);
} else {
// Notification has stopped
[_centralManager cancelPeripheralConnection:peripheral];
}
}
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error {
_discoveredPeripheral = nil;
[_centralManager scanForPeripheralsWithServices:#[[CBUUID UUIDWithString:BLUNO_TRANSFER_SERVICE_UUID]] options:#{ CBCentralManagerScanOptionAllowDuplicatesKey : #YES }];
}
#end
Here's your problem:
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI {
NSLog(#"Discovered %# at %#", peripheral.name, RSSI);
if (_discoveredPeripheral != peripheral) {
// Save a local copy of the peripheral, so CoreBluetooth doesn't get rid of it
_discoveredPeripheral = peripheral;
// And connect
NSLog(#"Connecting to peripheral %#", peripheral);
[_centralManager connectPeripheral:peripheral options:nil]; // <-- this is the issue
// then stop scanning for peripherals
[_centralManager stopScan];
NSLog(#"Scanning stopped");
}
}
You're connecting to a weakly held object, you should connect to your _discoveredPeripheral object instead. Also, don't forget to update your property calls to use your BCPeripheral object, for example:
[_discoveredPeripheral discoverServices:#[[CBUUID UUIDWithString:BLUNO_TRANSFER_SERVICE_UUID]]];