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2015-11-10 15:12
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作为一个中心要实现完整的通讯,一般要经过这样几个步骤:
建立中心角色—扫描外设(discover)—连接外设(connect)—扫描外设中的服务和特征(discover)—与外设做数据交互(explore and interact)—断开连接(disconnect)。
1建立中心角色
首先在我自己类的头文件中要包含CoreBluetooth的头文件,并继承两个协议<CBCentralManagerDelegate,CBPeripheralDelegate>,代码如下:
#import <CoreBluetooth/CoreBluetooth.h>
CBCentralManager *manager;
manager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
2扫描外设(discover)
代码如下:
[manager scanForPeripheralsWithServices:nil options:options];
这个参数应该也是可以指定特定的peripheral的UUID,那么理论上这个central只会discover这个特定的设备,但是我实际测试发现,如果用特定的UUID传参根本找不到任何设备,我用的代码如下:
NSArray *uuidArray = [NSArray arrayWithObjects:[CBUUID UUIDWithString:@"1800"],[CBUUID UUIDWithString:@"180A"],
[CBUUID UUIDWithString:@"1CB2D155-33A0-EC21-6011-CD4B50710777"],[CBUUID UUIDWithString:@"6765D311-DD4C-9C14-74E1-A431BBFD0652"],nil];
[manager scanForPeripheralsWithServices:uuidArray options:options];
目前不清楚原因,怀疑和设备本身在的广播包有关。
3连接外设(connect)
当扫描到4.0的设备后,系统会通过回调函数告诉我们设备的信息,然后我们就可以连接相应的设备,代码如下:
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
if(![_dicoveredPeripherals containsObject:peripheral])
[_dicoveredPeripherals addObject:peripheral];
NSLog(@"dicoveredPeripherals:%@", _dicoveredPeripherals);
}
//连接指定的设备
-(BOOL)connect:(CBPeripheral *)peripheral
{
NSLog(@"connect start");
_testPeripheral = nil;
[manager connectPeripheral:peripheral
options:[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:CBConnectPeripheralOptionNotifyOnDisconnectionKey]];
//开一个定时器监控连接超时的情况
connectTimer = [NSTimer scheduledTimerWithTimeInterval:5.0f target:self selector:@selector(connectTimeout:) userInfo:peripheral repeats:NO];
return (YES);
}
4扫描外设中的服务和特征(discover)
同样的,当连接成功后,系统会通过回调函数告诉我们,然后我们就在这个回调里去扫描设备下所有的服务和特征,代码如下:
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
[connectTimer invalidate];//停止时钟
NSLog(@"Did connect to peripheral: %@", peripheral);
_testPeripheral = peripheral;
[peripheral setDelegate:self];
[peripheral discoverServices:nil];
}
一个设备里的服务和特征往往比较多,大部分情况下我们只是关心其中几个,所以一般会在发现服务和特征的回调里去匹配我们关心那些,比如下面的代码:
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error
{
NSLog(@"didDiscoverServices");
if (error)
{
NSLog(@"Discovered services for %@ with error: %@", peripheral.name, [error localizedDescription]);
if ([self.delegate respondsToSelector:@selector(DidNotifyFailConnectService:withPeripheral:error:)])
[self.delegate DidNotifyFailConnectService:nil withPeripheral:nil error:nil];
return;
}
for (CBService *service in peripheral.services)
{
if ([service.UUID isEqual:[CBUUID UUIDWithString:UUIDSTR_ISSC_PROPRIETARY_SERVICE]])
{
NSLog(@"Service found with UUID: %@", service.UUID);
[peripheral discoverCharacteristics:nil forService:service];
isVPOS3356 = YES;
break;
}
}
}
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
{
if (error)
{
NSLog(@"Discovered characteristics for %@ with error: %@", service.UUID, [error localizedDescription]);
if ([self.delegate respondsToSelector:@selector(DidNotifyFailConnectChar:withPeripheral:error:)])
[self.delegate DidNotifyFailConnectChar:nil withPeripheral:nil error:nil];
return;
}
for (CBCharacteristic *characteristic in service.characteristics)
{
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:UUIDSTR_ISSC_TRANS_TX]])
{
NSLog(@"Discovered read characteristics:%@ for service: %@", characteristic.UUID, service.UUID);
_readCharacteristic = characteristic;//保存读的特征
if ([self.delegate respondsToSelector:@selector(DidFoundReadChar:)])
[self.delegate DidFoundReadChar:characteristic];
break;
}
}
for (CBCharacteristic * characteristic in service.characteristics)
{
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:UUIDSTR_ISSC_TRANS_RX]])
{
NSLog(@"Discovered write characteristics:%@ for service: %@", characteristic.UUID, service.UUID);
_writeCharacteristic = characteristic;//保存写的特征
if ([self.delegate respondsToSelector:@selector(DidFoundWriteChar:)])
[self.delegate DidFoundWriteChar:characteristic];
break;
}
}
if ([self.delegate respondsToSelector:@selector(DidFoundCharacteristic:withPeripheral:error:)])
[self.delegate DidFoundCharacteristic:nil withPeripheral:nil error:nil];
}
5与外设做数据交互(explore and interact)
发送数据很简单,我们可以封装一个如下的函数:
//写数据
-(void)writeChar:(NSData *)data
{
[_testPeripheral writeValue:data forCharacteristic:_writeCharacteristic type:CBCharacteristicWriteWithResponse];
}
_testPeripheral和_writeCharacteristic是前面我们保存的设备对象和可以读写的特征。
然后我们可以在外部调用它,比如当然我要触发刷卡时,先组好数据包,然后调用发送函数:
-(void)msrRead
{
unsigned char command[512] = {0};
unsigned charchar *pTmp;
int nSendLen = 0;
unsigned char ucCrc[3] = {0};
_commandType = COMMAND_MSR_READ;
pTmp = command;
*pTmp = 0x02;//start
pTmp++;
*pTmp = 0xc1;//main cmd
pTmp++;
*pTmp = 0x07;//sub cmd
pTmp++;
nSendLen = 2;
*pTmp = nSendLen/256;
pTmp++;
*pTmp = nSendLen%256;
pTmp++;
*pTmp = 0x00;//sub cmd
pTmp++;
*pTmp = 0x00;//sub cmd
pTmp++;
Crc16CCITT(command+1,pTmp-command-1,ucCrc);
memcpy(pTmp,ucCrc,2);
NSData *data = [[NSData alloc] initWithBytes:&command length:9];
NSLog(@"send data:%@", data);
[g_BLEInstance.recvData setLength:0];
[g_BLEInstance writeChar:data];
}
数据的读分为两种,一种是直接读(reading directly),另外一种是订阅(subscribe)。从名字也能基本理解两者的不同。实际使用中具体用一种要看具体的应用场景以及特征本身的属性。前一个好理解,特征本身的属性是指什么呢?特征有个properties字段(characteristic.properties),它是一个整型值,有如下几个定义:
enum {
CBCharacteristicPropertyBroadcast = 0x01,
CBCharacteristicPropertyRead = 0x02,
CBCharacteristicPropertyWriteWithoutResponse = 0x04,
CBCharacteristicPropertyWrite = 0x08,
CBCharacteristicPropertyNotify = 0x10,
CBCharacteristicPropertyIndicate = 0x20,
CBCharacteristicPropertyAuthenticatedSignedWrites = 0x40,
CBCharacteristicPropertyExtendedProperties = 0x80,
};
比如说,你要交互的特征,它的properties的值是0x10,表示你只能用订阅的方式来接收数据。我这里是用订阅的方式,启动订阅的代码如下:
//监听设备
-(void)startSubscribe
{
[_testPeripheral setNotifyValue:YES forCharacteristic:_readCharacteristic];
}
当设备有数据返回时,同样是通过一个系统回调通知我,如下所示:
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
{
if (error)
{
NSLog(@"Error updating value for characteristic %@ error: %@", characteristic.UUID, [error localizedDescription]);
if ([_mainMenuDelegate respondsToSelector:@selector(DidNotifyReadError:)])
[_mainMenuDelegate DidNotifyReadError:error];
return;
}
[_recvData appendData:characteristic.value];
if ([_recvData length] >= 5)//已收到长度
{
unsigned charchar *buffer = (unsigned charchar *)[_recvData bytes];
int nLen = buffer[3]*256 + buffer[4];
if ([_recvData length] == (nLen+3+2+2))
{
//接收完毕,通知代理做事
if ([_mainMenuDelegate respondsToSelector:@selector(DidNotifyReadData)])
[_mainMenuDelegate DidNotifyReadData];
}
}
}
6 断开连接(disconnect)
这个比较简单,只需要一个API就行了,代码如下:
//主动断开设备
-(void)disConnect
{
if (_testPeripheral != nil)
{
NSLog(@"disConnect start");
[manager cancelPeripheralConnection:_testPeripheral];
}
}
建立中心角色—扫描外设(discover)—连接外设(connect)—扫描外设中的服务和特征(discover)—与外设做数据交互(explore and interact)—断开连接(disconnect)。
1建立中心角色
首先在我自己类的头文件中要包含CoreBluetooth的头文件,并继承两个协议<CBCentralManagerDelegate,CBPeripheralDelegate>,代码如下:
#import <CoreBluetooth/CoreBluetooth.h>
CBCentralManager *manager;
manager = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
2扫描外设(discover)
代码如下:
[manager scanForPeripheralsWithServices:nil options:options];
这个参数应该也是可以指定特定的peripheral的UUID,那么理论上这个central只会discover这个特定的设备,但是我实际测试发现,如果用特定的UUID传参根本找不到任何设备,我用的代码如下:
NSArray *uuidArray = [NSArray arrayWithObjects:[CBUUID UUIDWithString:@"1800"],[CBUUID UUIDWithString:@"180A"],
[CBUUID UUIDWithString:@"1CB2D155-33A0-EC21-6011-CD4B50710777"],[CBUUID UUIDWithString:@"6765D311-DD4C-9C14-74E1-A431BBFD0652"],nil];
[manager scanForPeripheralsWithServices:uuidArray options:options];
目前不清楚原因,怀疑和设备本身在的广播包有关。
3连接外设(connect)
当扫描到4.0的设备后,系统会通过回调函数告诉我们设备的信息,然后我们就可以连接相应的设备,代码如下:
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
if(![_dicoveredPeripherals containsObject:peripheral])
[_dicoveredPeripherals addObject:peripheral];
NSLog(@"dicoveredPeripherals:%@", _dicoveredPeripherals);
}
//连接指定的设备
-(BOOL)connect:(CBPeripheral *)peripheral
{
NSLog(@"connect start");
_testPeripheral = nil;
[manager connectPeripheral:peripheral
options:[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:CBConnectPeripheralOptionNotifyOnDisconnectionKey]];
//开一个定时器监控连接超时的情况
connectTimer = [NSTimer scheduledTimerWithTimeInterval:5.0f target:self selector:@selector(connectTimeout:) userInfo:peripheral repeats:NO];
return (YES);
}
4扫描外设中的服务和特征(discover)
同样的,当连接成功后,系统会通过回调函数告诉我们,然后我们就在这个回调里去扫描设备下所有的服务和特征,代码如下:
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
[connectTimer invalidate];//停止时钟
NSLog(@"Did connect to peripheral: %@", peripheral);
_testPeripheral = peripheral;
[peripheral setDelegate:self];
[peripheral discoverServices:nil];
}
一个设备里的服务和特征往往比较多,大部分情况下我们只是关心其中几个,所以一般会在发现服务和特征的回调里去匹配我们关心那些,比如下面的代码:
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error
{
NSLog(@"didDiscoverServices");
if (error)
{
NSLog(@"Discovered services for %@ with error: %@", peripheral.name, [error localizedDescription]);
if ([self.delegate respondsToSelector:@selector(DidNotifyFailConnectService:withPeripheral:error:)])
[self.delegate DidNotifyFailConnectService:nil withPeripheral:nil error:nil];
return;
}
for (CBService *service in peripheral.services)
{
if ([service.UUID isEqual:[CBUUID UUIDWithString:UUIDSTR_ISSC_PROPRIETARY_SERVICE]])
{
NSLog(@"Service found with UUID: %@", service.UUID);
[peripheral discoverCharacteristics:nil forService:service];
isVPOS3356 = YES;
break;
}
}
}
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
{
if (error)
{
NSLog(@"Discovered characteristics for %@ with error: %@", service.UUID, [error localizedDescription]);
if ([self.delegate respondsToSelector:@selector(DidNotifyFailConnectChar:withPeripheral:error:)])
[self.delegate DidNotifyFailConnectChar:nil withPeripheral:nil error:nil];
return;
}
for (CBCharacteristic *characteristic in service.characteristics)
{
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:UUIDSTR_ISSC_TRANS_TX]])
{
NSLog(@"Discovered read characteristics:%@ for service: %@", characteristic.UUID, service.UUID);
_readCharacteristic = characteristic;//保存读的特征
if ([self.delegate respondsToSelector:@selector(DidFoundReadChar:)])
[self.delegate DidFoundReadChar:characteristic];
break;
}
}
for (CBCharacteristic * characteristic in service.characteristics)
{
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:UUIDSTR_ISSC_TRANS_RX]])
{
NSLog(@"Discovered write characteristics:%@ for service: %@", characteristic.UUID, service.UUID);
_writeCharacteristic = characteristic;//保存写的特征
if ([self.delegate respondsToSelector:@selector(DidFoundWriteChar:)])
[self.delegate DidFoundWriteChar:characteristic];
break;
}
}
if ([self.delegate respondsToSelector:@selector(DidFoundCharacteristic:withPeripheral:error:)])
[self.delegate DidFoundCharacteristic:nil withPeripheral:nil error:nil];
}
5与外设做数据交互(explore and interact)
发送数据很简单,我们可以封装一个如下的函数:
//写数据
-(void)writeChar:(NSData *)data
{
[_testPeripheral writeValue:data forCharacteristic:_writeCharacteristic type:CBCharacteristicWriteWithResponse];
}
_testPeripheral和_writeCharacteristic是前面我们保存的设备对象和可以读写的特征。
然后我们可以在外部调用它,比如当然我要触发刷卡时,先组好数据包,然后调用发送函数:
-(void)msrRead
{
unsigned char command[512] = {0};
unsigned charchar *pTmp;
int nSendLen = 0;
unsigned char ucCrc[3] = {0};
_commandType = COMMAND_MSR_READ;
pTmp = command;
*pTmp = 0x02;//start
pTmp++;
*pTmp = 0xc1;//main cmd
pTmp++;
*pTmp = 0x07;//sub cmd
pTmp++;
nSendLen = 2;
*pTmp = nSendLen/256;
pTmp++;
*pTmp = nSendLen%256;
pTmp++;
*pTmp = 0x00;//sub cmd
pTmp++;
*pTmp = 0x00;//sub cmd
pTmp++;
Crc16CCITT(command+1,pTmp-command-1,ucCrc);
memcpy(pTmp,ucCrc,2);
NSData *data = [[NSData alloc] initWithBytes:&command length:9];
NSLog(@"send data:%@", data);
[g_BLEInstance.recvData setLength:0];
[g_BLEInstance writeChar:data];
}
数据的读分为两种,一种是直接读(reading directly),另外一种是订阅(subscribe)。从名字也能基本理解两者的不同。实际使用中具体用一种要看具体的应用场景以及特征本身的属性。前一个好理解,特征本身的属性是指什么呢?特征有个properties字段(characteristic.properties),它是一个整型值,有如下几个定义:
enum {
CBCharacteristicPropertyBroadcast = 0x01,
CBCharacteristicPropertyRead = 0x02,
CBCharacteristicPropertyWriteWithoutResponse = 0x04,
CBCharacteristicPropertyWrite = 0x08,
CBCharacteristicPropertyNotify = 0x10,
CBCharacteristicPropertyIndicate = 0x20,
CBCharacteristicPropertyAuthenticatedSignedWrites = 0x40,
CBCharacteristicPropertyExtendedProperties = 0x80,
};
比如说,你要交互的特征,它的properties的值是0x10,表示你只能用订阅的方式来接收数据。我这里是用订阅的方式,启动订阅的代码如下:
//监听设备
-(void)startSubscribe
{
[_testPeripheral setNotifyValue:YES forCharacteristic:_readCharacteristic];
}
当设备有数据返回时,同样是通过一个系统回调通知我,如下所示:
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
{
if (error)
{
NSLog(@"Error updating value for characteristic %@ error: %@", characteristic.UUID, [error localizedDescription]);
if ([_mainMenuDelegate respondsToSelector:@selector(DidNotifyReadError:)])
[_mainMenuDelegate DidNotifyReadError:error];
return;
}
[_recvData appendData:characteristic.value];
if ([_recvData length] >= 5)//已收到长度
{
unsigned charchar *buffer = (unsigned charchar *)[_recvData bytes];
int nLen = buffer[3]*256 + buffer[4];
if ([_recvData length] == (nLen+3+2+2))
{
//接收完毕,通知代理做事
if ([_mainMenuDelegate respondsToSelector:@selector(DidNotifyReadData)])
[_mainMenuDelegate DidNotifyReadData];
}
}
}
6 断开连接(disconnect)
这个比较简单,只需要一个API就行了,代码如下:
//主动断开设备
-(void)disConnect
{
if (_testPeripheral != nil)
{
NSLog(@"disConnect start");
[manager cancelPeripheralConnection:_testPeripheral];
}
}
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