使用CoreBluetooth编写操作后无法读取数据

Question

Am Am New to Objective C Am试图从Arduino外围读取具有特定服务和特征的Arduino外围的数据，

两种不同的服务，

//arduino code

BLEService dataService("938548e6-c655-11ea-87d0-0242ac130003"); //Data reading
BLEService ledService("19B10000-E8F2-537E-4F6C-D104768A1214"); //LED control service


// Initialize dataService characteristics
BLECharacteristic dataArray("77539407-6493-4b89-985f-baaf4c0f8d86", BLERead | BLENotify, 114); // standard 16-bit characteristic UUID

// Initialize ledService characteristics
BLECharacteristic eventChar("19B10001-E8F2-537E-4F6C-D104768A1213", BLERead | BLEWrite, 1);

我能够通知 未从外围收到数据

    for (CBCharacteristic *characteristic in service. characteristics) {
        NSLog(@"Charecteristics %@", characteristic.UUID);
       
        if ([characteristic.UUID.UUIDString containsString: @"77539407"]) {
            NSLog(@"Specific Characteristics %@", characteristic.UUID);
//Working........ Characteristic 
            [peripheral setNotifyValue: YES forCharacteristic: characteristic];
        }
            if ([characteristic.UUID.UUIDString containsString: @"19B10001"]) {
                NSLog(@"Specific Charecteristics %@", characteristic.UUID);
                NSData *data = [@"01" dataUsingEncoding:NSUTF8StringEncoding];
                NSLog(@"WRITING DATA");
                NSLog(@"%@ : dataaaaaa",data);
                [peripheral writeValue: data forCharacteristic: characteristic
                type: CBCharacteristicWriteWithResponse];
            }
        }

并获得了第一个特征的读取值，以便在尝试写作时的第一个特征第二个特征在编写数据后，

- (void)peripheral:(CBPeripheral *)peripheral didWriteValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error {
    NSLog(@"didWrite");
    
    NSString *key = [self keyForPeripheral: peripheral andCharacteristic:characteristic];
    NSLog(@" writeCallback : %@ ",key);
    RCTResponseSenderBlock writeCallback = [writeCallbacks objectForKey:key];
    
    NSLog(@" writeCallback : %@ ",writeCallback);
    
    if (writeCallback) {
        if (error) {
            NSLog(@"%@", error);
            [writeCallbacks removeObjectForKey:key];
            writeCallback(@[error.localizedDescription]);
        } else {
            if ([writeQueue count] == 0) {
                NSLog(@"NO 1");
                [writeCallbacks removeObjectForKey:key];
                writeCallback(@[]);
            }else{
                // Remove and write the queud message
                NSLog(@"NO 2");
                NSData *message = [writeQueue objectAtIndex:0];
                [writeQueue removeObjectAtIndex:0];
                [peripheral writeValue:message forCharacteristic:characteristic type:CBCharacteristicWriteWithResponse];
            }
            
        }
    }
    
}

，它将转到 didwritevalueforchacteristic ，我为WriteCallback null for WriteCallback而言，有人可以向我解释我在

输出log