我试图用CoreBluetooth写一个特定的,已知的特征.我觉得这应该是可能的,因为我使用了一个德州仪器BLE实用程序,您可以在连接的外设上选择一个“写值”操作,只需输入特征UUID和您要编写的值,并且执行没有问题.
据我了解,为了做到这一点,我必须打电话
[peripheral writeValue:data forCharacteristic:...];
配置为具有正确的UUID的CBC特征对象.
我已经尝试使用正确的UUID进行CBMutableCharacteristic,甚至正确的权限,我知道的是这个外设的配置文件中的一个现有特性,并且当尝试执行任何读/写操作时,遇到以下崩溃：
*** Terminating app due to uncaught exception 'NSInvalidArgumentException',reason: '-[CBMutableCharacteristic peripheral]: unrecognized selector sent to instance 0x1ed57690'
这里是我用来设置和写入特性的代码：
NSString *characteristicUUIDstring = @"fff1"; CBUUID *characteristicUUID = [CBUUID UUIDWithString:characteristicUUIDstring]; char dataByte = 0x10; NSData *data = [NSData dataWithBytes:&dataByte length:1]; CBMutableCharacteristic *testCharacteristic = [[CBMutableCharacteristic alloc] initWithType:characteristicUUID properties:CBCharacteristicPropertyRead|CBCharacteristicPropertyWrite value:data permissions:CBAttributePermissionsReadable|CBAttributePermissionsWriteable]; [peripheral writeValue:data forCharacteristic:testCharacteristic type:CBCharacteristicWriteWithResponse];
解决方法
虽然这样的特性可能存在于外围设备中,但这并不是它所包含的实际特性.您需要发现您的所有服务和特征,然后直接从这些服务和字符写入.
//Assuming you've already discovered all your services and characteristics,do something like this:
for(CBService *service in peripheral.services)
{
if([service.UUID isEqual:theServiceCBUUIDYouAreLookingFor])
{
for(CBCharacteristic *charac in service.characteristics)
{
if([charac.UUID isEqual:theCharCBUUIDYoureLookingFor])
{
//NOW DO YOUR WRITING/READING AND YOU'LL BE GOOD TO GO
}
}
}
}
