Sounds like you have the Pi and Roomba both talking on the same wire, and both listening on the other wire.

Connect the Pi's TX line to the Roomba's RX line, and vice versa.

First rule for troubleshooting serial communications: Swap connections on pins 2 and 3!

Serial connection between Raspberry Pi and Roomba
Ok, so I've been using NSLog in objective-C for awhile now to debug and I know it's supposed to print to the terminal whatever I put in the parentheses. For some reason, it just stopped printing to the terminal and I'm not sure how to fix this error. I was wondering what other people would suggest doing to fix this problem. I've only included part of my code because I don't want to scare away someone from answering this simple (or at least I hope it's simple to fix) problem. When I run the code, the only two statements that print are "serverButton - Stage 1" and "serverButton - Stage 2 - Complete" but nothing else in between. FYI -(void)startServer is in another class called "Server" and I have made "server" a pointer to that said class.

-(IBAction)serverButton {
NSLog(@"serverButton - Stage 1");
[server startServer];
NSLog(@"serverButton - Stage 2 - Complete");
}

-(void)startServer {
    NSLog(@"serverButton - Stage 1");

    memset(&amp;hints, 0, sizeof hints);
    hints.ai_family = AF_UNSPEC; // set to AF_INET to force IPv4
    hints.ai_socktype = SOCK_DGRAM;
    hints.ai_flags = AI_PASSIVE; // use my IP

    if ((rv = getaddrinfo(NULL, MYPORT, &amp;hints, &amp;servinfo)) != 0) {
    	NSLog(@"ERROR: serverButton - Stage 1");
    	fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
    	serverError = 1;
    	NSLog(@"Error");
    }

