IOS Core Bluetooth : Writing NSData for Characteristic

Question

I am using the following code to write the 0xDE value for a Bluetooth Caracteristic (Reset Device) using the IOS Core Bluetooth :

...
NSData *bytes = [@\"0xDE\"          


        

Answer 1

This code will fix the problem :

NSData * data = [self  dataWithHexString: @"DE"];
[peripheral writeValue:data forCharacteristic:characteristic                                       
                            type:CBCharacteristicWriteWithResponse];

dataWithHexString implementation :

- (NSData *)dataWithHexString:(NSString *)hexstring
{
    NSMutableData* data = [NSMutableData data];
    int idx;
    for (idx = 0; idx+2 <= hexstring.length; idx+=2) {
        NSRange range = NSMakeRange(idx, 2);
        NSString* hexStr = [hexstring substringWithRange:range];
        NSScanner* scanner = [NSScanner scannerWithString:hexStr];
        unsigned int intValue;
        [scanner scanHexInt:&intValue];
        [data appendBytes:&intValue length:1];
    }
    return data;
}