在.m文件中
#import"ViewController.h"#import"NSString+SL_Extension.h"#import@interfaceViewController()@property(nonatomic,strong) CBCentralManager *cMgr;/**< 中心管理设备 *//** 连接到的外设 */@property(nonatomic,strong) CBPeripheral *peripheral;@property(strong,nonatomic) CBCharacteristic *writeCharacteristic;@property(nonatomic,strong)CBCharacteristic * characteristic;@end@implementationViewController// 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:selfqueue:dispatch_get_main_queue()];// 线程不传默认是主线程}return_cMgr;}- (void)viewDidLoad { [superviewDidLoad];self.title= @"大家好 我是山寨手环";self.view.backgroundColor= [UIColororangeColor];// 初始化[selfcMgr];// 不能在此处扫描,因为状态还没变为打开//[self.cMgr scanForPeripheralsWithServices:nil options:nil];}#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) {caseCBCentralManagerStateUnknown:NSLog(@">>>CBCentralManagerStateUnknown");break;caseCBCentralManagerStateResetting:NSLog(@">>>CBCentralManagerStateResetting");break;caseCBCentralManagerStateUnsupported:NSLog(@">>>CBCentralManagerStateUnsupported");break;caseCBCentralManagerStateUnauthorized:NSLog(@">>>CBCentralManagerStateUnauthorized");break;caseCBCentralManagerStatePoweredOff:NSLog(@">>>CBCentralManagerStatePoweredOff");break;caseCBCentralManagerStatePoweredOn: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.cMgrscanForPeripheralsWithServices:niloptions: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// 判断设备号是否扫描到if([peripheral.nameisEqualToString:@"iCre Band"]) {/*
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.peripheral= peripheral;// 发现完之后就是进行连接[self.cMgrconnectPeripheral:self.peripheraloptions:nil];NSLog(@"%s, line = %d", __FUNCTION__, __LINE__); }else{// 此处Alert提示未扫描到设备,重新扫描#warning noCodeNSLog(@"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);//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];// 停止扫描[self.cMgrstopScan];}// 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__);}#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:nilforService:service]; }}// 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; }#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// }for(CBCharacteristic * characteristic in service.characteristics) {// NSLog(@"查找到的服务（属性）%@",characteristic);//所对应的属性用于接收和发送数据NSLog(@"service:%@ 的 Characteristic: %@",service.UUID,characteristic.UUID);if([characteristic.UUIDisEqual:[CBUUID UUIDWithString:@"6E400003-B5A3-F393-E0A9-E50E24DCCA9E"]]) { [peripheral setNotifyValue:YESforCharacteristic:characteristic];//监听这个服务发来的数据[peripheral readValueForCharacteristic:characteristic];//主动去读取这个服务发来的数据}if([characteristic.UUIDisEqual:[CBUUID UUIDWithString:@"6E400002-B5A3-F393-E0A9-E50E24DCCA9E"]]) { _writeCharacteristic = characteristic; }if([characteristic.UUIDisEqual:[CBUUID UUIDWithString:@"6E400001-B5A3-F393-E0A9-E50E24DCCA9E"]]) {// [peripheral setNotifyValue:YES forCharacteristic:characteristic];//监听这个服务发来的数据// [peripheral readValueForCharacteristic:characteristic];//主动去读取这个服务发来的数据} }}// 获取characteristic的值- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullableNSError*)error{ NSData * data = characteristic.value; Byte * resultByte = (Byte *)[data bytes];for(inti=0;i<[data length];i++){ printf("testByteFF02[%d] = %d\n",i,resultByte[i]);}//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if([characteristic.UUIDisEqual:[CBUUID UUIDWithString:@"6E400003-B5A3-F393-E0A9-E50E24DCCA9E"]]) { Byte *databyte = (Byte *)[characteristic.valuebytes];for(inti =0; i<[characteristic.valuelength]; i++) {NSLog(@"收到3蓝牙发来的数据 %d",databyte[i]); }// NSString * string = [NSString hexadecimalString:characteristic.value];NSLog(@"----------%@",characteristic.value);//在这里解析收到的数据，一般是data类型的数据，这里要根据蓝牙厂商提供的协议进行解析并且配合LightBlue来查看数据结构，我当时收到的数据是十六进制的数据但是是data类型，所以我先讲data解析出来之后转为十进制来使用。具体方法后面我会贴出//还有一点收到数据后有的硬件是需要应答的，如果应答的话就是在这里再给蓝牙发一个指令（写数据）：“我收到发的东西了，你那边要做什么操作可以做了”。}if([characteristic.UUIDisEqual:[CBUUID UUIDWithString:@"6E400001-B5A3-F393-E0A9-E50E24DCCA9E"]]) { Byte *databyte = (Byte *)[characteristic.valuebytes];for(inti =0; i<[characteristic.valuelength]; i++) {NSLog(@"收到1蓝牙发来的数据 %d",databyte[i]); }NSString* string = [NSStringhexadecimalString:characteristic.value];NSLog(@"----------%@",[NSStringstringFromHexString:string]);//在这里解析收到的数据，一般是data类型的数据，这里要根据蓝牙厂商提供的协议进行解析并且配合LightBlue来查看数据结构，我当时收到的数据是十六进制的数据但是是data类型，所以我先讲data解析出来之后转为十进制来使用。具体方法后面我会贴出//还有一点收到数据后有的硬件是需要应答的，如果应答的话就是在这里再给蓝牙发一个指令（写数据）：“我收到发的东西了，你那边要做什么操作可以做了”。}if([characteristic.UUIDisEqual:[CBUUID UUIDWithString:@"6E400002-B5A3-F393-E0A9-E50E24DCCA9E"]]) { Byte *databyte = (Byte *)[characteristic.valuebytes];for(inti =0; i<[characteristic.valuelength]; i++) {NSLog(@"收到2蓝牙发来的数据 %d",databyte[i]); }//在这里解析收到的数据，一般是data类型的数据，这里要根据蓝牙厂商提供的协议进行解析并且配合LightBlue来查看数据结构，我当时收到的数据是十六进制的数据但是是data类型，所以我先讲data解析出来之后转为十进制来使用。具体方法后面我会贴出//还有一点收到数据后有的硬件是需要应答的，如果应答的话就是在这里再给蓝牙发一个指令（写数据）：“我收到发的东西了，你那边要做什么操作可以做了”。}NSString*dataStr = [[NSStringalloc]initWithData:characteristic.valueencoding:NSUTF8StringEncoding];NSLog(@"%s, line = %d, characteristic.UUID:%@ value:%@", __FUNCTION__, __LINE__, characteristic.UUID, dataStr);}// 获取Characteristics的 descriptor的值- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForDescriptor:(nonnull CBDescriptor *)descriptor error:(nullableNSError*)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NSString*dataStr = [[NSStringalloc]initWithData:descriptor.valueencoding:NSUTF8StringEncoding];NSLog(@"%s, line = %d, characteristic.UUID:%@ value:%@", __FUNCTION__, __LINE__, descriptor.UUID, dataStr);}// 发现特征Characteristics的描述Descriptor- (void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullableNSError*)error{NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);for(CBDescriptor *descriptor in characteristic.descriptors) {NSLog(@"descriptor.UUID:%@",descriptor.UUID); }}// 5.外设写数据到特征中// 需要注意的是特征的属性是否支持写数据- (void)sl_peripheral:(CBPeripheral *)peripheral didWriteData:(NSData *)data forCharacteristic:(nonnull 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, char.pro = %d", __FUNCTION__, __LINE__, characteristic.properties);// 此时由于枚举属性是NS_OPTIONS,所以一个枚举可能对应多个类型,所以判断不能用 = ,而应该用包含&if(characteristic.properties& CBCharacteristicPropertyWrite) {// 核心代码在这里[peripheral writeValue:data// 写入的数据forCharacteristic:characteristic// 写给哪个特征type:CBCharacteristicWriteWithResponse];// 通过此响应记录是否成功写入}}// 6.通知的订阅和取消订阅// 实际核心代码是一个方法// 一般这两个方法要根据产品需求来确定写在何处- (void)sl_peripheral:(CBPeripheral *)peripheral regNotifyWithCharacteristic:(nonnull CBCharacteristic *)characteristic{// 外设为特征订阅通知 数据会进入 peripheral:didUpdateValueForCharacteristic:error:方法[peripheral setNotifyValue:YESforCharacteristic:characteristic];}- (void)sl_peripheral:(CBPeripheral *)peripheral CancleRegNotifyWithCharacteristic:(nonnull CBCharacteristic *)characteristic{// 外设取消订阅通知 数据会进入 peripheral:didUpdateValueForCharacteristic:error:方法[peripheral setNotifyValue:NOforCharacteristic:characteristic];}// 7.断开连接- (void)sl_dismissConentedWithPeripheral:(CBPeripheral *)peripheral{// 停止扫描[self.cMgrstopScan];// 断开连接[self.cMgrcancelPeripheralConnection:peripheral];}- (IBAction)sendMessageToBan:(id)sender {//crc //unsignedchardata0 [5]= {0}; data0[0] =0x6; *(data0+1) =0x0; *(data0+2) =0x10; *(data0+3) =0x0; *(data0+4) =0x0; uint16_t bb = bd_crc16(0,data0,sizeof(data0));NSLog(@"收到1蓝牙发来的数据%d",bb);unsignedchardata [13]= {0}; data[0] =0xab; *(data+1) =0x0; *(data+2) =0x0; *(data+3) =0x5; *(data+4) =0xc5; *(data+5) =0x89; *(data+6) =0x0; *(data+7) =0x1e; *(data+8) =0x6; *(data+9) =0x0; *(data+10) =0x10; *(data+11) =0x0; *(data+12) =0x0;// *(data+5) = 0x0;NSData *data1 = [NSData dataWithBytes:data length:sizeof(data)];if(_peripheral.state== CBPeripheralStateConnected) { [_peripheral writeValue:data1 forCharacteristic:_writeCharacteristic type:CBCharacteristicWriteWithResponse]; }}//用于检测中心向外设写数据是否成功-(void)peripheral:(CBPeripheral *)peripheral didWriteValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError*)error{if(error) {NSLog(@"发送数据失败=======%@",error.userInfo); }else{//马达接口//ab 0 0 5 5 d8 0 50 6 0 11 0 0unsignedchardata [13]= {0};//Magic byte,有 效值为 0XABdata[0] =0xab;//Reserve 2 bits ERR flag Ack flag Version*(data+1) =0x0;//Payload length*(data+2) =0x0;//*(data+3) =0x5;//CRC16*(data+4) =0x1;//*(data+5) =0x68;//Sequence id*(data+6) =0x0; *(data+7) =0x3c;//*(data+8) =0x6;//*(data+9) =0x0;//*(data+10) =0x6;//*(data+11) =0x0;//*(data+12) =0x0;// *(data+5) = 0x0;NSData *data1 = [NSData dataWithBytes:data length:sizeof(data)];if(_peripheral.state== CBPeripheralStateConnected) { [_peripheral writeValue:data1 forCharacteristic:_writeCharacteristic type:CBCharacteristicWriteWithResponse]; }NSLog(@"发送数据成功"); } [peripheral readValueForCharacteristic:characteristic];}-(NSData *)hexString:(NSString*)hexString {intj=0; Byte bytes[20];///3ds key的Byte 数组， 128位for(inti=0; i<[hexString length]; i++) {intint_ch;/// 两位16进制数转化后的10进制数unicharhex_char1 = [hexString characterAtIndex:i];////两位16进制数中的第一位(高位*16)intint_ch1;if(hex_char1 >='0'&& hex_char1 <='9') int_ch1 = (hex_char1-48)*16;//// 0 的Ascll - 48elseif(hex_char1 >='A'&& hex_char1 <='F') int_ch1 = (hex_char1-55)*16;//// A 的Ascll - 65elseint_ch1 = (hex_char1-87)*16;//// a 的Ascll - 97i++;unicharhex_char2 = [hexString characterAtIndex:i];///两位16进制数中的第二位(低位)intint_ch2;if(hex_char2 >='0'&& hex_char2 <='9') int_ch2 = (hex_char2-48);//// 0 的Ascll - 48elseif(hex_char1 >='A'&& hex_char1 <='F') int_ch2 = hex_char2-55;//// A 的Ascll - 65elseint_ch2 = hex_char2-87;//// a 的Ascll - 97int_ch = int_ch1+int_ch2;NSLog(@"int_ch=%d",int_ch); bytes[j] = int_ch;///将转化后的数放入Byte数组里j++; } NSData *newData = [[NSData alloc] initWithBytes:bytes length:20];returnnewData;}//停止手环振动- (IBAction)stopShake:(id)sender {unsignedchardata [13]= {0}; data[0] =0xab; *(data+1) =0x0; *(data+2) =0x0; *(data+3) =0x5; *(data+4) =0x5; *(data+5) =0xd8; *(data+6) =0x0; *(data+7) =0x50; *(data+8) =0x6; *(data+9) =0x0; *(data+10) =0x11; *(data+11) =0x0; *(data+12) =0x0;// *(data+5) = 0x0;NSData *data1 = [NSData dataWithBytes:data length:sizeof(data)];if(_peripheral.state== CBPeripheralStateConnected) { [_peripheral writeValue:data1 forCharacteristic:_writeCharacteristic type:CBCharacteristicWriteWithResponse]; }}staticinlineuint16_t crc16_byte(uint16_t crc,constuint8_t data){return(crc >>8) ^ crc16_table[(crc ^ data) &0xff];}/** CRC table for the CRC-16. The poly is 0x8005 (x^16 + x^15 + x^2 + 1) */uint16_tconstcrc16_table[256] ={0x0000,0xC0C1,0xC181,0x0140,0xC301,0x03C0,0x0280,0xC241,0xC601,0x06C0,0x0780,0xC741,0x0500,0xC5C1,0xC481,0x0440,0xCC01,0x0CC0,0x0D80,0xCD41,0x0F00,0xCFC1,0xCE81,0x0E40,0x0A00,0xCAC1,0xCB81,0x0B40,0xC901,0x09C0,0x0880,0xC841,0xD801,0x18C0,0x1980,0xD941,0x1B00,0xDBC1,0xDA81,0x1A40,0x1E00,0xDEC1,0xDF81,0x1F40,0xDD01,0x1DC0,0x1C80,0xDC41,0x1400,0xD4C1,0xD581,0x1540,0xD701,0x17C0,0x1680,0xD641,0xD201,0x12C0,0x1380,0xD341,0x1100,0xD1C1,0xD081,0x1040,0xF001,0x30C0,0x3180,0xF141,0x3300,0xF3C1,0xF281,0x3240,0x3600,0xF6C1,0xF781,0x3740,0xF501,0x35C0,0x3480,0xF441,0x3C00,0xFCC1,0xFD81,0x3D40,0xFF01,0x3FC0,0x3E80,0xFE41,0xFA01,0x3AC0,0x3B80,0xFB41,0x3900,0xF9C1,0xF881,0x3840,0x2800,0xE8C1,0xE981,0x2940,0xEB01,0x2BC0,0x2A80,0xEA41,0xEE01,0x2EC0,0x2F80,0xEF41,0x2D00,0xEDC1,0xEC81,0x2C40,0xE401,0x24C0,0x2580,0xE541,0x2700,0xE7C1,0xE681,0x2640,0x2200,0xE2C1,0xE381,0x2340,0xE101,0x21C0,0x2080,0xE041,0xA001,0x60C0,0x6180,0xA141,0x6300,0xA3C1,0xA281,0x6240,0x6600,0xA6C1,0xA781,0x6740,0xA501,0x65C0,0x6480,0xA441,0x6C00,0xACC1,0xAD81,0x6D40,0xAF01,0x6FC0,0x6E80,0xAE41,0xAA01,0x6AC0,0x6B80,0xAB41,0x6900,0xA9C1,0xA881,0x6840,0x7800,0xB8C1,0xB981,0x7940,0xBB01,0x7BC0,0x7A80,0xBA41,0xBE01,0x7EC0,0x7F80,0xBF41,0x7D00,0xBDC1,0xBC81,0x7C40,0xB401,0x74C0,0x7580,0xB541,0x7700,0xB7C1,0xB681,0x7640,0x7200,0xB2C1,0xB381,0x7340,0xB101,0x71C0,0x7080,0xB041,0x5000,0x90C1,0x9181,0x5140,0x9301,0x53C0,0x5280,0x9241,0x9601,0x56C0,0x5780,0x9741,0x5500,0x95C1,0x9481,0x5440,0x9C01,0x5CC0,0x5D80,0x9D41,0x5F00,0x9FC1,0x9E81,0x5E40,0x5A00,0x9AC1,0x9B81,0x5B40,0x9901,0x59C0,0x5880,0x9841,0x8801,0x48C0,0x4980,0x8941,0x4B00,0x8BC1,0x8A81,0x4A40,0x4E00,0x8EC1,0x8F81,0x4F40,0x8D01,0x4DC0,0x4C80,0x8C41,0x4400,0x84C1,0x8581,0x4540,0x8701,0x47C0,0x4680,0x8641,0x8201,0x42C0,0x4380,0x8341,0x4100,0x81C1,0x8081,0x4040};/**
* crc16 - compute the CRC-16 for the data buffer
* @crc: previous CRC value 之前的crc值
* @buffer: data pointer data指针
* @len: number of bytes in the buffer 字节数
*
* Returns the updated CRC value.
*/uint16_t bd_crc16(uint16_t crc, uint8_tconst*buffer, uint16_t len){while(len--) crc = crc16_byte(crc, *buffer++);returncrc;}@end