Question

I have not been able to find this information anywhere. How long can a string be send with the TTL version of the redpark cable?

The following delegate method is called twice when I print something thorough serial from my Arduino, an example of a string is this: 144;480,42;532,40;20e

- (void) readBytesAvailable:(UInt32)length{

When I use the new function methods of retrieving available data [getStringFromBytesAvailable] I will only get 144;480,42;532,40; and then the whole function is called again and the string now contains the rest of the string: 20e

The following method is working for appending the two strings, but only if the rate of data transmission is ‘slow’ (1 time a second, I would prefer minimum 10 times a second).

–

 (void) readBytesAvailable:(UInt32)length{

    if(string && [string rangeOfString:@"e"].location == NSNotFound){
        string = [string stringByAppendingString:[rscMgr getStringFromBytesAvailable]];
        NSLog(string);
        finishedReading = YES;
    }
    else{
        string = [rscMgr getStringFromBytesAvailable];

    }


    if (finishedReading == YES) 
     {

        //do stuff

     }
        finishedReading = NO;
        string = nil;
    }

}

But can you tell my why the methods is called twice if I write a “long” string, and how to avoid this issue?

Answer 1

Since your program fragment runs faster then the time it takes to send a string, you need to capture the bytes and append them to a string.

If the serial data is terminated with a carriage return you can test for it to know when you have received the entire string.

Then you can allow your Arduino to send 10 times a second.