BLE中心模式流程-coding
BLE中心模式流程
- 1.建立中心角色
- 2.扫描外设(Discover Peripheral)
- 3.连接外设(Connect Peripheral)
- 4.扫描外设中的服务和特征(Discover Services And Characteristics)
- 4.1 获取外设的services
- 4.2 获取外设的Characteristics,获取characteristics的值,,获取Characteristics的Descriptor和Descriptor的值
- 5.利用特征与外设做数据交互(Explore And Interact)
- 6.订阅Characteristic的通知
- 7.断开连接(Disconnect)
准备环境
- 1.Xcode7.0
- 2.手机
- 3.外设(手机+LightBlue)
实现步骤
1.导入CB头文件,建立主设备管理类,设置主设备代理
#import
@interface XMGBLEController ()
@property (nonatomic, strong) CBCentralManager *cMgr; /**< 中心管理设备 */
@end
@implementation XMGBLEController
#pragma mark - 懒加载
// 1.建立中心管理者
- (CBCentralManager *)cMgr
{
if (!_cMgr) {
NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
/*
设置主设备的代理,CBCentralManagerDelegate
必须实现的：
- (void)centralManagerDidUpdateState:(CBCentralManager *)central;//主设备状态改变调用，在初始化CBCentralManager的适合会打开设备，只有当设备正确打开后才能使用
其他选择实现的委托中比较重要的：
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI; //找到外设
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;//连接外设成功
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//外设连接失败
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//断开外设
*/
_cMgr = [[CBCentralManager alloc] initWithDelegate:self queue:dispatch_get_main_queue()]; // 线程不传默认是主线程
}
return _cMgr;
}
- (void)viewDidLoad {
[super viewDidLoad];
self.title = @"BLE";
self.view.backgroundColor = [UIColor orangeColor];
// 初始化
[self cMgr];
// 不能在此处扫描,因为状态还没变为打开
//[self.cMgr scanForPeripheralsWithServices:nil options:nil];
}
2.扫描外设
- 扫描的方法防治cMgr成功打开的代理方法中
- 只有设备成功打开,才能开始扫描,否则会报错
#pragma mark - CBCentralManagerDelegate
// 中心管理者状态改变, 在初始化CBCentralManager的时候会打开设备，只有当设备正确打开后才能使用
- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
switch (central.state) {
case CBCentralManagerStateUnknown:
NSLog(@">>>CBCentralManagerStateUnknown");
break;
case CBCentralManagerStateResetting:
NSLog(@">>>CBCentralManagerStateResetting");
break;
case CBCentralManagerStateUnsupported:
NSLog(@">>>CBCentralManagerStateUnsupported");
break;
case CBCentralManagerStateUnauthorized:
NSLog(@">>>CBCentralManagerStateUnauthorized");
break;
case CBCentralManagerStatePoweredOff:
NSLog(@">>>CBCentralManagerStatePoweredOff");
break;
case CBCentralManagerStatePoweredOn:
NSLog(@">>>CBCentralManagerStatePoweredOn");
// 2.开始扫描周围的外设
/*
第一个参数nil就是扫描周围所有的外设，扫描到外设后会进入
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI;
*/
[self.cMgr scanForPeripheralsWithServices:nil options:nil];
break;
default:
break;
}
}
// 扫描到设备会进入到此代理方法
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
NSLog(@"%s, line = %d, per = %@, data = %@, rssi = %@", __FUNCTION__, __LINE__, peripheral, advertisementData, RSSI);
// 接下来连接设备
}
3.连接外设
-
扫描手环,打印结果
Snip20150928_5.png 根据打印结果
// 扫描到设备会进入到此代理方法
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
NSLog(@"%s, line = %d, per = %@, data = %@, rssi = %@", __FUNCTION__, __LINE__, peripheral, advertisementData, RSSI);
// 3.接下来可以连接设备
//如果你没有设备，可以下载一个app叫lightbule的app去模拟一个设备
//这里自己去设置下连接规则，我设置的是二维码扫描到的运动手环的设备号
// 判断设备号是否扫描到
if ([peripheral.name isEqualToString:@"OBand-75"]) {
/*
一个主设备最多能连7个外设，每个外设最多只能给一个主设备连接,连接成功，失败，断开会进入各自的委托
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;//连接外设成功的委托
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//外设连接失败的委托
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//断开外设的委托
*/
// 保存外设,否则方法结束就销毁
self.per = peripheral;
[self.cMgr connectPeripheral:self.per options:nil];
}else
{
// 此处Alert提示未扫描到设备,重新扫描
#warning noCode
NSLog(@"没扫描到 >>>>>>>> %s, line = %d", __FUNCTION__, __LINE__);
}
}
// 外设连接成功
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
NSLog(@">>>连接到名称为（%@）的设备-成功",peripheral.name);
}
// 外设连接失败
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error
{
NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
}
// 断开连接(丢失连接)
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error
{
NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
}
4.扫描外设中的服务和特征
设备链接成功后,就可以扫描设备的服务(services)了,同样是通过代理,扫描到结果后会触发某代理方法.
注意:此时CBCentralManagerDelegate已经不能满足需求,需要新的CBPeripheralDelegate来搞定.
该协议中包含了central与peripheral的许多回调方法
(eg.:获取services,获取characteristics,获取characteristics的值,获取characteristics的Descriptor以及Descriptor的值,写数据,读RSSI,用通知的方式订阅数据等等).
- 4.1 获取外设的services
- 首先设置外设的代理,并搜寻services
- 然后在代理方法
peripheral:didDiscoverServices:中遍历services
// 外设连接成功
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
NSLog(@">>>连接到名称为（%@）的设备-成功",peripheral.name);
//设置的peripheral代理CBPeripheralDelegate
//@interface ViewController : UIViewController
[peripheral setDelegate:self];
//扫描外设Services，成功后会进入方法：-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{
[peripheral discoverServices:nil];
/*
Discovers the specified services of the peripheral.
An array of CBUUID objects that you are interested in. Here, each CBUUID object represents a UUID that identifies the type of service you want to discover.
*/
}
#pragma mark - CBPeripheralDelegate
// 发现外设的service
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error
{
if (error)
{
NSLog(@">>>Discovered services for %@ with error: %@", peripheral.name, [error localizedDescription]);
return;
}
for (CBService *service in peripheral.services) {
NSLog(@"service.UUID = %@", service.UUID);
//扫描每个service的Characteristics，扫描到后会进入方法： -(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
[peripheral discoverCharacteristics:nil forService:service];
}
}
- 4.2 获取外设的characteris,获取Characteristics的值,获取Characteristics的Descriptor以及Descriptor的值
// 外设发现service的特征
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
{
if (error)
{
NSLog(@"error Discovered characteristics for %@ with error: %@", service.UUID, [error localizedDescription]);
return;
}
for (CBCharacteristic *characteristic in service.characteristics)
{
NSLog(@"service:%@ 的 Characteristic: %@",service.UUID,characteristic.UUID);
}
#warning noCodeFor 优化,分开写是为了让大家看注释清晰,并不符合编码规范
//获取Characteristic的值，读到数据会进入方法：-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
for (CBCharacteristic *characteristic in service.characteristics){
[peripheral readValueForCharacteristic:characteristic]; // 外设读取特征的值
}
//搜索Characteristic的Descriptors，读到数据会进入方法：-(void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
for (CBCharacteristic *characteristic in service.characteristics){
[peripheral discoverDescriptorsForCharacteristic:characteristic]; // 外设发现特征的描述
}
}
// 获取characteristic的值
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullable NSError *)error
{
//打印出characteristic的UUID和值
//!注意，value的类型是NSData，具体开发时，会根据外设协议制定的方式去解析数据
NSLog(@"%s, line = %d, characteristic.UUID:%@ value:%@", __FUNCTION__, __LINE__, characteristic.UUID, characteristic.value);
}
// 获取Characteristics的 descriptor的值
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForDescriptor:(nonnull CBDescriptor *)descriptor error:(nullable NSError *)error
{
//打印出DescriptorsUUID 和value
//这个descriptor都是对于characteristic的描述，一般都是字符串，所以这里我们转换成字符串去解析
NSLog(@"%s, line = %d, descriptor.UUID:%@ value:%@", __FUNCTION__, __LINE__, descriptor.UUID, descriptor.value);
}
// 发现特征Characteristics的描述Descriptor
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullable NSError *)error
{
NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
for (CBDescriptor *descriptor in characteristic.descriptors) {
NSLog(@"descriptor.UUID:%@",descriptor.UUID);
}
}
5.写数据到特征中
// 5.将数据写入特征(自定义方法,为了看的更清楚,没别的意思)
- (void)yf_peripheral:(CBPeripheral *)peripheral writeData:(NSData *)data forCharacteristic:(CBCharacteristic *)characteristic
{
/*
typedef NS_OPTIONS(NSUInteger, CBCharacteristicProperties) {
CBCharacteristicPropertyBroadcast = 0x01,
CBCharacteristicPropertyRead = 0x02,
CBCharacteristicPropertyWriteWithoutResponse = 0x04,
CBCharacteristicPropertyWrite = 0x08,
CBCharacteristicPropertyNotify = 0x10,
CBCharacteristicPropertyIndicate = 0x20,
CBCharacteristicPropertyAuthenticatedSignedWrites = 0x40,
CBCharacteristicPropertyExtendedProperties = 0x80,
CBCharacteristicPropertyNotifyEncryptionRequired NS_ENUM_AVAILABLE(NA, 6_0) = 0x100,
CBCharacteristicPropertyIndicateEncryptionRequired NS_ENUM_AVAILABLE(NA, 6_0) = 0x200
};
打印出特征的权限(characteristic.properties),可以看到有很多种,这是一个NS_OPTIONS的枚举,可以是多个值
常见的又read,write,noitfy,indicate.知道这几个基本够用了,前俩是读写权限,后俩都是通知,俩不同的通知方式
*/
NSLog(@"%s, line = %d, characteristic.properties:%d", __FUNCTION__, __LINE__, characteristic.properties);
// 只有特征的properties中有写的属性时候,才写
if (characteristic.properties & CBCharacteristicPropertyWrite) {
// 这句才是正宗的核心代码
[peripheral writeValue:data forCharacteristic:characteristic type:CBCharacteristicWriteWithResponse];
}
}
6.订阅特征的通知
// 设置通知
- (void)yf_peripheral:(CBPeripheral *)peripheral setNotifyForCharacteristic:(CBCharacteristic *)characteristic
{
// 设置通知, 数据会进入 peripheral:didUpdateValueForCharacteristic:error:方法
[peripheral setNotifyValue:YES forCharacteristic:characteristic];
}
// 取消通知
- (void)yf_peripheral:(CBPeripheral *)peripheral cancelNotifyForCharacteristic:(CBCharacteristic *)characteristic
{
[peripheral setNotifyValue:NO forCharacteristic:characteristic];
}
7.断开连接
// 7.断开连接
- (void)yf_cMgr:(CBCentralManager *)cMgr stopScanAndDisConnectWithPeripheral:(CBPeripheral *)peripheral
{
// 停止扫描
[cMgr stopScan];
// 断开连接
[cMgr cancelPeripheralConnection:peripheral];
}
8.项目中遇到的坑
- 写给外设数据格式问题
- 跟硬件工程师沟通，需要传输的数据类型，一般都是传byte字节数组，可能需要用到的方法
#pragma mark - MD5加密
-(NSString *)md5:(NSString *)inPutText
{
const char *cStr = [inPutText UTF8String];
unsigned char result[CC_MD5_DIGEST_LENGTH];
CC_MD5(cStr, strlen(cStr), result);
return [[NSString stringWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
result[0], result[1], result[2], result[3],
result[4], result[5], result[6], result[7],
result[8], result[9], result[10], result[11],
result[12], result[13], result[14], result[15]
] lowercaseString];
}
#pragma mark - 将NSString转换成十六进制的字符串则可使用如下方式:
- (NSString *)convertStringToHexStr:(NSString *)str {
if (!str || [str length] == 0) {
return @"";
}
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
NSMutableString *string = [[NSMutableString alloc] initWithCapacity:[data length]];
[data enumerateByteRangesUsingBlock:^(const void *bytes, NSRange byteRange, BOOL *stop) {
unsigned char *dataBytes = (unsigned char*)bytes;
for (NSInteger i = 0; i < byteRange.length; i++) {
NSString *hexStr = [NSString stringWithFormat:@"%x", (dataBytes[i]) & 0xff];
if ([hexStr length] == 2) {
[string appendString:hexStr];
} else {
[string appendFormat:@"0%@", hexStr];
}
}
}];
return string;
}
#pragma mark - 将十六进制的字符串转换为需要的data，这就是你最终需要写入的数据:
+ (NSData *)dataWithHexString:(NSString *)hexstring
{
NSMutableData* data = [NSMutableData data];
int idx;
for (idx = 0; idx+2 <= hexstring.length; idx+=2) {
NSRange range = NSMakeRange(idx, 2);
NSString* hexStr = [hexstring substringWithRange:range];
NSScanner* scanner = [NSScanner scannerWithString:hexStr];
unsigned int intValue;
[scanner scanHexInt:&intValue];
[data appendBytes:&intValue length:1];
}
return data;
}
- 读取数据格式问题
- 读取的也是byte数组
#pragma mark - 更新特征的value的时候会调用 （凡是从蓝牙传过来的数据都要经过这个回调，简单的说这个方法就是你拿数据的唯一方法） 你可以判断是否
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
{
NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
NSLog(@"***********");
if (error) {
NSLog(@"error:%@",error.localizedDescription);
return;
}
NSData * data = characteristic.value;
Byte * resultByte = (Byte *)[data bytes];
NSLog(@"rusultByte:%s",resultByte);
for(int i=0;i<[data length];i++){
printf("testByteFF02[%d] = %d\n",i,resultByte[i]);
if (resultByte[i]==0) { // 授权成功
self.count++;
self.writeFinishFlag = YES;
break;
// [self.deviceManager writeValue:[@"Lock" dataUsingEncoding:NSUTF8StringEncoding] forCharacteristic:characteristic type:CBCharacteristicWriteWithResponse];
}else{
self.writeFinishFlag = NO;
}
}
if (self.count==1&& self.writeFinishFlag) { // // 授权成功
NSLog(@"授权成功");
if (self.lockCharacteristic.properties & CBCharacteristicPropertyWrite) {
// [self notifyCharacteristic:peripheral characteristic:characteristic];
// NSData *data = [NSData dataWithHexString:@"Lock"];
NSString *lock = [self convertStringToHexStr:@"Lock"];
NSLog(@"lock:%@",lock);
// NSData *data = [@"Lock" dataUsingEncoding:NSUTF8StringEncoding];
NSData *data = [NSData dataWithHexString:lock];
NSLog(@"lockData:%@",data);
[self.deviceManager writeValue:data forCharacteristic:self.lockCharacteristic type:CBCharacteristicWriteWithResponse];// 激活锁
if (characteristic.properties & CBCharacteristicPropertyRead) {
// [peripheral readValueForCharacteristic:characteristic];
}
}
}
if (self.count==2&& self.writeFinishFlag) {// 激活成功
NSLog(@"激活成功");
if (self.lockCharacteristic.properties & CBCharacteristicPropertyWrite) {
// [self notifyCharacteristic:peripheral characteristic:characteristic];
NSString *unLock = [self convertStringToHexStr:@"Unlock"];
NSData *data = [NSData dataWithHexString:unLock];
NSLog(@"unlockData;%@",data);
[self.deviceManager writeValue:data forCharacteristic:self.lockCharacteristic type:CBCharacteristicWriteWithResponse];// 开锁
if (characteristic.properties & CBCharacteristicPropertyRead) {
// [peripheral readValueForCharacteristic:characteristic];
}
}
}
if (self.count==3&& self.writeFinishFlag) {// 开锁成功
NSLog(@"开锁成功");
[self.bleManager cancelPeripheralConnection:self.deviceManager];// 断开链接
[self.bleManager stopScan];
self.bleManager = nil;
}
}
//base64解密
NSData *decodedData = [[NSData alloc] initWithBase64EncodedString:base64String options:0];
NSString *decodedString = [[NSString alloc] initWithData:decodedData encoding:NSUTF8StringEncoding];
- 设置通知只需要在发现服务特征值的方法中设置一次即可，另外设置了通知这个方法基本上不用[peripheral readValueForCharacteristic:cha];因为它会频繁调用- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error 会导致读取数据失败，总之根据工程师给的文档一步一步来！