I'm currently developing an iPhone application regarding the communication between iPhone and OBDKey via wifi. So far so good. I managed to establish the TCP/IP communication using CFStream. My problem now: When I send some message to the OBDKey, the response is the exact same message.
I think the faulty code is somewhere in the stream method of the application. But I can't figure it out.
I hope you can give me some advice.
Here is the code:
CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
NSInputStream *inputStream;
NSOutputStream *outputStream;
@implementation Communicator
@synthesize textField; //Gegenstück zu @property im .h File
@synthesize textView; //Gegenstück zu @property im .h File
- (IBAction)connectPressed:(id)sender {
host = @"192.168.0.74";
port = 23;
//Ausgabe
[self debugPrint:[NSString stringWithFormat:@"Setting up connection to %@ : %i", host, port]];
//Stream wird erzeugt mit Host, Port, Read & Write stream
CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, (__bridge CFStringRef)(host), port, &readStream, &writeStream);
//Überprüfung ob Write Stream funktioniert
if (!CFWriteStreamOpen(writeStream)) {
[self debugPrint:[NSString stringWithFormat:@"Error, writeStream not open"]];
return;
}
//Methode open wird geöffnet
[self open];
[self debugPrint:[NSString stringWithFormat:@"Status of outputStream: %i", [outputStream streamStatus]]];
return;
}
//Hier werden sowohl der Output(Write)- als auch der Input(Read)-Stream geöffnet.
- (void)open {
[self debugPrint:[NSString stringWithFormat:@"Opening streams..."]];
//Da Automatic Reference Counting betrieben wird, muss eine __bridge Notation gesetzt werden um
//das Objekt hin und her verwenden zu können.
inputStream = (__bridge NSInputStream *)readStream;
outputStream = (__bridge NSOutputStream *)writeStream;
[inputStream setDelegate:self];
[outputStream setDelegate:self];
//RunLoop wird verwendet um input und output Objekte zu managen (Reihenfolgen usw.)
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[inputStream open];
[outputStream open];
//Überprüfung ob beide Streams geöffnet wurden
if (!inputStream && !outputStream)
{
[self debugPrint:[NSString stringWithFormat:@"Error. Could not open streams!"]];
return;
}
//[self debugPrint:[NSString stringWithFormat:@"Streams are open"]];
}
//Disconnect Button wird gedrückt - Hierbei werden alle input und output streams geschlossen
//und RunLoops geschlossen
- (IBAction)disconnectPressed:(id)sender {
[inputStream close];
[outputStream close];
[inputStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[inputStream setDelegate:nil];
[outputStream setDelegate:nil];
inputStream = nil;
outputStream = nil;
[self debugPrint:[NSString stringWithFormat:@"Session closed!"]];
}
//Methode welche den eingegeben Text vom TextField in das TextView schreibt
- (IBAction)sendPressed:(id)sender {
//Hier wird überprüft ob eine Eingabe im textField erfolgt ist (ob Zeichen eingegeben wurden)
if ([[textField text] length] > 0) {
NSString *textFieldString = [textField text];
[self writeOut:(NSString *)textFieldString];
[self.textField endEditing:YES];
}
}
- (IBAction)clearViewPressed:(id)sender {
textView.text = nil;
}
//Methode in der Text formatiert im textView angezeigt werden kann
- (void)debugPrint:(NSString *)text {
textView.text = [textView.text stringByAppendingFormat: @"\n%@", text];
}
//Methode die Zuständig ist zum Stream handling
//NSStreamEventNone = 0
//NSStreamEventOpenCompleted = 1
//NSStreamHasBytesAvailable = 2
//NSStreamHasSpaceAvailable = 4
//NSStreamEventErrorOccurred = 8
//NSStreamEventEndEncountered = 16
- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)event {
if (stream.streamStatus == 2){
[self debugPrint:[NSString stringWithFormat:@"Stream opened"]];
}
switch (event) {
case NSStreamEventHasSpaceAvailable: {
if (stream == outputStream){
[self debugPrint:[NSString stringWithFormat:@"Ouput stream is ready!"]];
}
break;
}
case NSStreamEventHasBytesAvailable: {
if (stream == inputStream) {
[self debugPrint:[NSString stringWithFormat:@"Input stream is ready!"]];
uint8_t buf[1024];
unsigned int len = 0; //len wird nie negativ sein => unsigned
len = [inputStream read:buf maxLength:1024];
if (len > 0) {
NSMutableData* data=[[NSMutableData alloc] initWithLength:0];
//data wird mit Daten aus dem Buffer buf gefüttert (maximale Länge len)
[data appendBytes: (const void *)buf length:len];
//Erlaubt die Konvertierung eines Datenstrings in einen Characterstring
NSString *raw_data = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
//sends raw_data to readIn method
[self readIn:raw_data];
}
}
break;
}
default: {
[self debugPrint:[NSString stringWithFormat:@"Stream is sending an Event: %u", event]];
break;
}
}
}
- (void)readIn:(NSString *)s {
[self debugPrint:[NSString stringWithFormat:@"Reading:"]];
[self debugPrint:[NSString stringWithFormat:@"%@",s]];
}
- (void)writeOut:(NSString *)string {
uint8_t *buf = (uint8_t *)[string UTF8String];
[outputStream write:buf maxLength:strlen((char *)buf)];
[self debugPrint:[NSString stringWithFormat:@"%s\r\n",buf]];
//[self debugPrint:[NSString stringWithFormat:@"Sent:"]];
//[self debugPrint:[NSString stringWithFormat:@"%@\r\n",string]];
}
@end
Thank you in advance!!!
EDIT 1: I've tried my code using the terminal application on my Mac with Telnet (127.0.0.1:23). Both, sending and receiving works perfectly. But the response from the OBKey is the same as the request I'm sending.
EDIT 2: I figured it out: I have to send the initialising handshake commands to start the actual communication (ATZ, ATSP0 and ATL1). I've done this in a seperate method that is called up in the connection process of the app.
Greets, qoob
