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[英]iOS CoreBluetooth - Peripheral connect to Central within range
[英]iOS CoreBluetooth:Sending data from central and getting response from peripheral
我正在开发蓝牙应用程序。 我已连接到蓝牙设备,并在其中找到了服务和特性。 我在从中央发送写请求并从外围设备接收响应时遇到问题。 我写了下面的代码来写数据。 我怎么知道外围设备收到了这些数据? 我可以在外围设备显示任何警报吗? 并且,以同样的方式,我想从外围设备接收数据,以便中心应显示警报,表明它已收到外围设备的响应。
这是我编写的以下代码
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:
(CBService *)service error:(NSError *)error {
if (!error) {
printf("Characteristics of service with UUID : %s found\r\n",[self
CBUUIDToString:service.UUID]);
for(int i=0; i < service.characteristics.count; i++) {
CBCharacteristic *c = [service.characteristics objectAtIndex:i];
printf("Found characteristic %s\r\n",[ self CBUUIDToString:c.UUID]);
CBService *s = [peripheral.services objectAtIndex:(peripheral.services.count - 1)];
if([self compareCBUUID:service.UUID UUID2:s.UUID])
{
printf("Finished discovering characteristics");
break;
}
}
}
else {
printf("Characteristic discorvery unsuccessfull !\r\n");
}
}
用于写值
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:
(CBCharacteristic *)characteristic error:(NSError *)error
{
NSString *payloadMessage = @"Hello";
NSData *payload = [payloadMessage dataUsingEncoding:NSUTF8StringEncoding];
[peripheral writeValue:payload forCharacteristic:characteristic
type:CBCharacteristicWriteWithResponse];
}
我需要获取ble设备的版本,即GET_VERSION = 0x4a; 请对此提供帮助,否则请提供任何示例以从这两个设备写入和读取数据。
蓝牙中央设备可以通过两种方式从外围设备接收数据-
关于使用哪种方法,数据将通过调用didUpdateValueForCharacteristic:
委托方法来传递。
似乎您对这种方法的目的有些困惑,因为您的代码在那里发出了写请求,这可能不是您想要的。
在写入数据时,您可以在有或没有响应的情况下写入数据。 您的代码指定了响应。 在这种情况下,当外围设备确认该写入时,将调用您的didWriteValueForCharacteristic
委托方法-这就是您知道已接收到数据的方式。
一些简单的代码可以实现您在问题中描述的行为:
-(void)sendData:(NSData *)data {
[self.connectedPeripheral writeValue:data forCharacteristic:self.someCharacteristic type:CBCharacteristicWriteWithResponse];
}
- (void)peripheral:(CBPeripheral *)peripheral
didWriteValueForCharacteristic:(CBCharacteristic *)characteristic
error:(NSError *)error {
if (error == nil) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Wrote characteristic" message:@"Successfully wrote characteristic" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"ok"];
[alert show];
}
else {
NSLog(@"Error writing characteristic %@",error);
}
}
-(void)readCharacteristic {
[self.connectedPeripheral readCharacteristic:self.someOtherCharacteristic];
}
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
{
if (error == nil) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Read characteristic" message:[NSString stringWithFormat:@"Successfully read characteristic %@",characteristic.value] delegate:nil cancelButtonTitle:nil otherButtonTitles:@"ok"];
[alert show];
}
else {
NSLog(@"Error reading characteristic %@",error);
}
}
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