[iOS 基于CoreBluetooth的蓝牙4.0通讯]

时间:2023-03-09 21:50:47
[iOS 基于CoreBluetooth的蓝牙4.0通讯]

一、首先大致介绍下蓝牙4.0的模式,中心和周边:

[iOS 基于CoreBluetooth的蓝牙4.0通讯]

一般情况下,iPhone作为中心,接收来自周边传感器(比如手环等)采集的数据。

二、那整一个数据通讯的协议是怎样的呢?

[iOS 基于CoreBluetooth的蓝牙4.0通讯]

为什么要一层层搞这么复杂呢?据我的理解是这样的:

  (1)蓝牙2.0的通讯非常简单,只有数据接收和发送,这样产生的问题就是:假如我有2个传感器的数据,但传输通道就一个,就发送时必须自己切割字符串等。

      但4.0根据不同的功能,有点像传输分了很多“通道”,比如传感器1传输温度,服务的UUID是FFF0,然后特征字节发送的UUID为FFF1;传感器2传输距离,服务的UUID也是FFF0,但是特征字节发送的UUID为FFF2,这样就可以各取所需了,而不是蓝牙2.0那样一股脑儿收进来再切割。

  (2)蓝牙4.0的每个“通道”都可以定义为发送或者接收字节,所以可以把发送和接收区分开。

  补充:一般情况下,服务(Service)的UUID根据功能来区分(假如有FFF0和FFFE0两种服务),比如FFF0的服务ID里的特征字节UUID通道用来作为传感器通讯,FFE0里放蓝牙设备的信息,名称啊电池啊等等。。

三、代码:

1.BLEInfo.h(存放周边蓝牙设备的信息)

#import <Foundation/Foundation.h>
#import <CoreBluetooth/CoreBluetooth.h>
@interface BLEInfo : NSObject @property (nonatomic, strong) CBPeripheral *discoveredPeripheral;
@property (nonatomic, strong) NSNumber *rssi; @end

BLEInfo.m

#import "BLEInfo.h"

@implementation BLEInfo

@end

2.RootTableViewController.h(显示周边蓝牙信息,主要用scan函数就行了)

#import <UIKit/UIKit.h>
#import <CoreBluetooth/CoreBluetooth.h>
#import "BLEInfo.h"
#import "DetailViewController.h"
@interface RootTableViewController : UITableViewController<CBCentralManagerDelegate> @property (nonatomic, strong) CBCentralManager *centralMgr;
@property (nonatomic, strong) NSMutableArray *arrayBLE; @end

RootTableViewController.m

#import "RootTableViewController.h"

@interface RootTableViewController ()

@end

@implementation RootTableViewController

- (void)viewDidLoad {
[super viewDidLoad];
self.navigationItem.title=@"蓝牙搜索";
self.centralMgr = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
self.arrayBLE = [[NSMutableArray alloc] init];
} - (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
} //蓝牙状态delegate
- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
switch (central.state)
{
case CBCentralManagerStatePoweredOn:
[self.centralMgr scanForPeripheralsWithServices:nil options:nil];
NSLog(@"start scan Peripherals"); break; default:
NSLog(@"Central Manager did change state");
break;
}
} //发现设备delegate
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
BLEInfo *discoveredBLEInfo = [[BLEInfo alloc] init];
discoveredBLEInfo.discoveredPeripheral = peripheral;
discoveredBLEInfo.rssi = RSSI; // update tableview
[self saveBLE:discoveredBLEInfo]; } //保存设备信息
- (BOOL)saveBLE:(BLEInfo *)discoveredBLEInfo
{
for (BLEInfo *info in self.arrayBLE)
{
if ([info.discoveredPeripheral.identifier.UUIDString isEqualToString:discoveredBLEInfo.discoveredPeripheral.identifier.UUIDString])
{
return NO;
}
} NSLog(@"\nDiscover New Devices!\n");
NSLog(@"BLEInfo\n UUID:%@\n RSSI:%@\n\n",discoveredBLEInfo.discoveredPeripheral.identifier.UUIDString,discoveredBLEInfo.rssi); [self.arrayBLE addObject:discoveredBLEInfo];
[self.tableView reloadData];
return YES;
} #pragma mark - Table view data source - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Return the number of sections.
return ;
} - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// Return the number of rows in the section.
return _arrayBLE.count;
} - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:@"cell"]; // Step 2: If there are no cells to reuse, create a new one
if(cell == nil) cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"cell"];
// Add a detail view accessory
BLEInfo *thisBLEInfo=[self.arrayBLE objectAtIndex:indexPath.row];
cell.textLabel.text=[NSString stringWithFormat:@"%@ %@",thisBLEInfo.discoveredPeripheral.name,thisBLEInfo.rssi];
cell.detailTextLabel.text=[NSString stringWithFormat:@"UUID:%@",thisBLEInfo.discoveredPeripheral.identifier.UUIDString];
// Step 3: Set the cell text // Step 4: Return the cell
return cell;
} - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{ BLEInfo *thisBLEInfo=[self.arrayBLE objectAtIndex:indexPath.row];
DetailViewController* dtvc=[self.storyboard instantiateViewControllerWithIdentifier:@"DetailViewController"];
dtvc.centralMgr=self.centralMgr;
dtvc.discoveredPeripheral=thisBLEInfo.discoveredPeripheral; [self.navigationController pushViewController:dtvc animated:YES]; }
@end

3.DetailViewController.h(连接具体的蓝牙,发现其内部信息)

#import <UIKit/UIKit.h>
#import <CoreBluetooth/CoreBluetooth.h> @interface DetailViewController : UIViewController<
CBPeripheralManagerDelegate,
CBCentralManagerDelegate,
CBPeripheralDelegate
> @property (nonatomic, strong) CBCentralManager *centralMgr;
@property (nonatomic, strong) CBPeripheral *discoveredPeripheral;
@property (strong, nonatomic) CBCharacteristic* writeCharacteristic; @property int current_humitidy;
@property int current_temperature; - (IBAction)led1control:(id)sender; @end

DetailViewController.m

#import "DetailViewController.h"

@interface DetailViewController ()

@end

@implementation DetailViewController

#define SECTION_NAME @"Serviceinfo"

- (void)viewDidLoad
{
[super viewDidLoad]; [_centralMgr setDelegate:self];
if (_discoveredPeripheral)
{
NSLog(@"connectPeripheral");
[_centralMgr connectPeripheral:_discoveredPeripheral options:nil];
}
} //界面退出
-(void)viewWillDisappear:(BOOL)animated{
[self.centralMgr cancelPeripheralConnection:_discoveredPeripheral];
} - (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
} /*
//========================================================================================
//0.假设蓝牙关闭、掉线什么的,重新搜索
- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
switch (central.state)
{
case CBCentralManagerStatePoweredOn:
//[self.centralMgr scanForPeripheralsWithServices:nil options:nil];
NSLog(@"start scan Peripherals"); break; default:
NSLog(@"Central Manager did change state");
break;
}
} //1.搜索后重连
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
//[_centralMgr connectPeripheral:_discoveredPeripheral options:nil];
}
//========================================================================================
*/ //2.连接的Delegate 连接若成功则搜索服务
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error
{
NSLog(@"didFailToConnectPeripheral : %@", error.localizedDescription);
} - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{ [_discoveredPeripheral setDelegate:self]; //查找服务
[_discoveredPeripheral discoverServices:nil];
} //========================================================================================
//3.搜索服务的Delegate 若发现服务,然后搜索其内的特征服务 - (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error
{
if (error)
{
NSLog(@"didDiscoverServices : %@", [error localizedDescription]);
// [self cleanup];
return;
} for (CBService *s in peripheral.services)
{
NSLog(@"\n>>>服务UUID found with UUID : %@ des:%@", s.UUID,s.UUID.description);
//查找特征字节
[s.peripheral discoverCharacteristics:nil forService:s];
}
}
//========================================================================================
//4.搜索特征的Delegate 若发现特征,则看看这个“通道是发送的还是接收”,接收就read,发送就把这个writeCharacteristic记录下
//注意:不是所有的特性值都是可读的(readable)。通过访问 CBCharacteristicPropertyRead 可以知道特性值是否可读。如果一个特性的值不可读,使用 peripheral:didUpdateValueForCharacteristic:error:就会返回一个错误。
//Subscribing to a Characteristic’s Value(订制一个特性值) 尽管通过 readValueForCharacteristic:方法能够得到特性值,但是对于一个变化的特性值就不是很 有效了。大多数的特性值是变化的,比如一个心率监测应用,如果需要得到特性值,就需要 通过预定的方法获得。当预定了一个特性值,当值改变时,就会收到设备发出的通知。 /*特征值的属性:c.properties
typedef NS_OPTIONS(NSInteger, CBCharacteristicProperties) {
// 标识这个characteristic的属性是广播
CBCharacteristicPropertyBroadcast= 0x01,
// 标识这个characteristic的属性是读
CBCharacteristicPropertyRead= 0x02,
// 标识这个characteristic的属性是写-没有响应
CBCharacteristicPropertyWriteWithoutResponse= 0x04,
// 标识这个characteristic的属性是写
CBCharacteristicPropertyWrite= 0x08,
// 标识这个characteristic的属性是通知
CBCharacteristicPropertyNotify= 0x10,
// 标识这个characteristic的属性是声明
CBCharacteristicPropertyIndicate= 0x20,
// 标识这个characteristic的属性是通过验证的
CBCharacteristicPropertyAuthenticatedSignedWrites= 0x40,
// 标识这个characteristic的属性是拓展
CBCharacteristicPropertyExtendedProperties= 0x80,
// 标识这个characteristic的属性是需要加密的通知
CBCharacteristicPropertyNotifyEncryptionRequiredNS_ENUM_AVAILABLE(NA, 6_0)= 0x100,
// 标识这个characteristic的属性是需要加密的申明
CBCharacteristicPropertyIndicateEncryptionRequiredNS_ENUM_AVAILABLE(NA, 6_0)= 0x200
};
*/
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
{
if (error)
{
NSLog(@"didDiscoverCharacteristicsForService error : %@", [error localizedDescription]);
return;
} for (CBCharacteristic *c in service.characteristics)
{
NSLog(@"\n>>>\t特征UUID FOUND(in 服务UUID:%@): %@ (data:%@)",service.UUID.description,c.UUID,c.UUID.data); /*
根据特征不同属性去读取或者写
if (c.properties==CBCharacteristicPropertyRead) {
}
if (c.properties==CBCharacteristicPropertyWrite) {
}
if (c.properties==CBCharacteristicPropertyNotify) {
}
*/ //假如你和硬件商量好了,某个UUID时写,某个读的,那就不用判断啦
/*
if([c.UUID isEqual:[CBUUID UUIDWithString:@"FFF1"]]){
self.writeCharacteristic = c;
}
if([c.UUID isEqual:[CBUUID UUIDWithString:@"FFF6"]]){
[peripheral readValueForCharacteristic:c];
}*/
if (c.properties==CBCharacteristicPropertyRead) {
[peripheral readValueForCharacteristic:c];
}
}
}
//======================================================================================== - (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
{
if (error)
{
NSLog(@"didUpdateValueForCharacteristic error : %@", error.localizedDescription);
return;
} NSLog(@"\nFindtheValueis (UUID:%@):%@ ",characteristic.UUID,characteristic.value); /*
if([characteristic.UUID.description isEqualToString:@"FFF6"]){
//我这里采用的是16进制数据,如<34001a00>,3400代表湿度十进制52.0,1a00代表温度26.0
//当然你也可以有自己定义传输字符的意义
NSData *datavalue=characteristic.value;
NSData *shidudata=[datavalue subdataWithRange:NSMakeRange(0, 1)];
NSData *wendudata=[datavalue subdataWithRange:NSMakeRange(2, 1)];
NSLog(@"\nFind---theValueis:%@ %@-%@",characteristic.value,shidudata,wendudata);
int i=0,j=0;
[shidudata getBytes: &i length: sizeof(i)];
[wendudata getBytes: &j length: sizeof(j)]; self.current_humitidy=i;
self.current_temperature=j; NSLog(@"\n室内温度为:%d℃,室内湿度为:%d%%",_current_temperature,_current_humitidy);
}
*/
} - (void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
if (error) {
NSLog(@"Error changing notification state: %@", [error localizedDescription]);
}
} //向peripheral中写入数据后的回调函数
- (void)peripheral:(CBPeripheral*)peripheral didWriteValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{
NSLog(@"write value success : %@", characteristic);
} //自定义的写入数据的函数
- (void)writeToPeripheral:(NSString *)string{
if(!_writeCharacteristic){
NSLog(@"writeCharacteristic is nil!");
return;
} NSData* value = [self stringToByte:string];
NSLog(@"Witedata: %@",value); [_discoveredPeripheral writeValue:value forCharacteristic:_writeCharacteristic type:CBCharacteristicWriteWithResponse];
} //====================================================================================================
//一些转换函数,本例中只用到stringToByte
-(NSData*)stringToByte:(NSString*)string
{
NSString *hexString=[[string uppercaseString] stringByReplacingOccurrencesOfString:@" " withString:@""];
if ([hexString length]%!=) {
return nil;
}
Byte tempbyt[]={};
NSMutableData* bytes=[NSMutableData data];
for(int i=;i<[hexString length];i++)
{
unichar hex_char1 = [hexString characterAtIndex:i]; ////两位16进制数中的第一位(高位*16)
int int_ch1;
if(hex_char1 >= '' && hex_char1 <='')
int_ch1 = (hex_char1-)*; //// 0 的Ascll - 48
else if(hex_char1 >= 'A' && hex_char1 <='F')
int_ch1 = (hex_char1-)*; //// A 的Ascll - 65
else
return nil;
i++; unichar hex_char2 = [hexString characterAtIndex:i]; ///两位16进制数中的第二位(低位)
int int_ch2;
if(hex_char2 >= '' && hex_char2 <='')
int_ch2 = (hex_char2-); //// 0 的Ascll - 48
else if(hex_char2 >= 'A' && hex_char2 <='F')
int_ch2 = hex_char2-; //// A 的Ascll - 65
else
return nil; tempbyt[] = int_ch1+int_ch2; ///将转化后的数放入Byte数组里
[bytes appendBytes:tempbyt length:];
}
return bytes;
} //NSData类型转换成NSString
- (NSString*)hexadecimalString:(NSData *)data{
NSString* result;
const unsigned char* dataBuffer = (const unsigned char*)[data bytes];
if(!dataBuffer){
return nil;
}
NSUInteger dataLength = [data length];
NSMutableString* hexString = [NSMutableString stringWithCapacity:(dataLength * )];
for(int i = ; i < dataLength; i++){
[hexString appendString:[NSString stringWithFormat:@"%02lx", (unsigned long)dataBuffer[i]]];
}
result = [NSString stringWithString:hexString];
return result;
}
//==================================================================================================== //假设有个swt1,开一下发送一个开关信号,控制LED灯
- (IBAction)led1control:(id)sender {
UISwitch *swt1= (UISwitch*)sender;
if (swt1.on) {
[self writeToPeripheral:@""];
}else{
[self writeToPeripheral:@""]; }
} @end

完整代码地址:https://github.com/rayshen/ShenBLETest

四、示例:基于蓝牙4.0的温湿度采集控制器

这是我自己做的湿度和温度的收集器和控制器。

iPhone收集来自单片机(蓝牙CC2541芯片)的温度和湿度信息,并且可以控制LED灯和继电器。

继电器就是一个开关,外围可以连接其他带电源和电器的大电路。

[iOS 基于CoreBluetooth的蓝牙4.0通讯]

欢迎大家和我交流,我的微博是:weibo.com/rayshen1012