Question

我设置了两个视图控制器，一个UITableView，可以处理所有扫描并连接到设备。一旦发现设备及其服务和特性，我将返回主屏幕，按下按钮，它将数据发送到我连接的外围设备。然而，从我正在阅读的外围设备中没有收到任何信息。当我尝试从UITableView写入设备时，它确实有效。

以下是按下按钮的代码

- (IBAction)Unlock:(id)sender {


uint8_t val = 12; //data to send
NSData* valData = [NSData dataWithBytes:(void*)&val length:sizeof(val)];

//check if peripheral is connected
if (!myPeriph) { 
    NSLog(@"Not connected to a peripheral");
}
// check for characteristic 
if (!myChar) {
    NSLog(@"No valid characteristic");
    return;
}
NSLog(@"Writing value for characteristic %@", myChar);
//write data to peripheral
[myPeriph writeValue:valData forCharacteristic:myChar
                 type:CBCharacteristicWriteWithoutResponse];


}

这是可行的代码

- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
{


    // Deal with errors (if any)
    if (error) {
        NSLog(@"Error discovering characteristics: %@", [error localizedDescription]);
        // [self cleanup];
        return;
    }

    // Again, we loop through the array, just in case.
    for (CBCharacteristic *characteristic in service.characteristics) {
        NSLog(@"Discovered characteristic %@",characteristic);
        if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]]) {

            // If it is, subscribe to it
            //[peripheral setNotifyValue: forCharacteristic:characteristic];


            //store characteristic as variable
            Connected_Characteristic= characteristic;
            NSLog(@"Connected Char %@",Connected_Characteristic);


            uint8_t val = 12; //data to send
      NSData* valData = [NSData dataWithBytes:(void*)&val length:sizeof(val)];

         //write data to peripheral
[Connected_Peripheral writeValue:valData forCharacteristic:Connected_Characteristic
                 type:CBCharacteristicWriteWithoutResponse];

        //pass peripheral and characteristic back to main screen        
            [self.delegate didSelectWith:self device:Connected_Peripheral device_characteristics:Connected_Characteristic];

          //pop back to main screen  
            [self.navigationController popViewControllerAnimated:YES];
        }

    }

}

我不确定我做错了什么。我想我可能必须在'didDiscoverCharacteristicsForServices'函数中，但我已经看到另一个在它之外调用write方法的例子。

此外，myPeriph和myChar在这里宣布

-(void)didSelectWith:(deviceViewController *)controller device:(CBPeripheral *)device device_characteristics:(CBCharacteristic *)device_characteristics

{

    self.myPeriph=device;
    self.myChar=device_characteristics;

    [controller dismissViewControllerAnimated:YES completion:nil];
    NSLog(@"device %@ characteristic %@ ",myPeriph, myChar);

    }

并从上面的函数传递并成功工作。

按下按钮将数据发送到外围设备

0 个答案: