What is wrong with this code???? It won't Compile and I don't know why? Please Help

[Dave Flowerday]

Here's what I found in the users guide:

1105: symbol ‘%s’ has not been defined
A symbol has been referenced before it has been defined. Common causes
include a misspelled symbol name, a missing header file that declares the
symbol, and a reference to a symbol valid only in an inner scope.

On the error line when you compile, is there something after the word 'symbol'? (i.e. did it not get pasted to CD right, or does it just not show up?)

I pasted your code into an editor and it looks like line 367 is "if (drive_timer > LOST_TARGET_TIMEOUT)", is that correct? If so, can you show us the section from the header file that defines "LOST_TARGET_TIMEOUT"?

[CrashZero]

That was all there was in the compile box and I posted the whole .c file; is there a different file that you want to see???

[Astronouth7303]

Originally Posted by CrashZero

That was all there was in the compile box and I posted the whole .c file; is there a different file that you want to see???

1- use the [code] tag.
2- Is this a file you wrote/modified?
3- Is there a Navigate.h? that might be what he is talking about.
4- Did you write this code?

[EricS-Team180]

Hi,

He'd like you to post your Navigate.h header file, to look at how LOST_TARGET_TIMEOUT is defined...if that is where it is defined.

You could also do a search, through the folder that you have your code in, to see if it turns up anywhere. If not, then the you've found your error

Eric Schreffler

[Astronouth7303]

Or, in MPLAB, Project>Find in Project files... and type in "LOST_TARGET_TIMEOUT" (w/o quotes). in the Output window, see where it comes up.

[Alan Anderson]

Dave's right, the compiler is complaining about line 367:

if (drive_timer > LOST_TARGET_TIMEOUT)

But the compiler output appears to be truncated. It's supposed to tell you what name it doesn't recognize. There might be an invisible character in the source file on that line, which the compiler would choke on and be unable to display. The easiest thing to do at this point would be to duplicate the line, character by character, without doing a copy/paste, then delete the original line and try compiling again.

If that doesn't help, then show us the section of the header file where LOST_TARGET_TIMEOUT is defined (probably in navigate.h).

(Oh, and next time you need to post programs here, surround it with [CODE] and [/CODE] so the formatting is preserved.)

[Biff]

Originally Posted by Alan Anderson

Dave's right, the compiler is complaining about line 367:

if (drive_timer > LOST_TARGET_TIMEOUT)

But the compiler output appears to be truncated. It's supposed to tell you what name it doesn't recognize. There might be an invisible character in the source file on that line, which the compiler would choke on and be unable to display. The easiest thing to do at this point would be to duplicate the line, character by character, without doing a copy/paste, then delete the original line and try compiling again.

If that doesn't help, then show us the section of the header file where LOST_TARGET_TIMEOUT is defined (probably in navigate.h).

(Oh, and next time you need to post programs here, surround it with [CODE] and [/CODE] so the formatting is preserved.)

This C stuff is new to me, but the { }'s around line 367 I can't figure out if they all make sense, I think you may have some that are unmatched. Hope this helps

[Alan Anderson]

Originally Posted by Biff

This C stuff is new to me, but the { }'s around line 367 I can't figure out if they all make sense, I think you may have some that are unmatched. Hope this helps

Oh, my. There's certainly something odd going on:

case DR_BOTH_CENTER:
{
    Navigator_State = AT_TARGET; // Both servos are within the target threshold
    printf("AT_TARGET\n");
    break;
}
}
}
    else
    {
        // We are not locked on - Stop
        // give the trackers a chance to catch up
        left_drive_set = LSTOP;
        right_drive_set = RSTOP;
        drive_timer++ ;
        if (drive_timer > LOST_TARGET_TIMEOUT) 
        {
            Navigator_State = TURN_TO_TARGET;
            printf("TURN_TO_TARGET\n"); // Done driving to center
            left_servo_set = 127;
            right_servo_set = 127;
        }
    }
    break;
}

There are three }s in a row right before a naked else statement. This source code is apparently missing a few lines, including an if.

There is also a case statement commented out near the top of the big switch. That can't be doing what you want, can it? If you want to "skip" that state, as the comments suggest, I think you need to initialize your state variable to DRIVE_TO_CENTER instead of WAIT_TO_DRIVE in line 37.

[Dave Scheck]

Originally Posted by Alan Anderson

here are three }s in a row right

Looks weird, but I think they match up.
357 matches to 353 (case DR_BOTH_CENTER)
358 matches to 258(switch drive_state)
359 matches to 207(if Tracker_Data...)

I think that you're onto something with that commented case at line 131. That's definately not right

[Greg Ross]

Originally Posted by Alan Anderson

Oh, my. There's certainly something odd going on:

case DR_BOTH_CENTER:
{
    Navigator_State = AT_TARGET; // Both servos are within the target threshold
    printf("AT_TARGET\n");
    break;
}
}
}
    else
    {
        // We are not locked on - Stop
        // give the trackers a chance to catch up
        left_drive_set = LSTOP;
        right_drive_set = RSTOP;
        drive_timer++ ;
        if (drive_timer > LOST_TARGET_TIMEOUT) 
        {
            Navigator_State = TURN_TO_TARGET;
            printf("TURN_TO_TARGET\n"); // Done driving to center
            left_servo_set = 127;
            right_servo_set = 127;
        }
    }
    break;
}

There are three }s in a row right before a naked else statement. This source code is apparently missing a few lines, including an if.

There is also a case statement commented out near the top of the big switch. That can't be doing what you want, can it? If you want to "skip" that state, as the comments suggest, I think you need to initialize your state variable to DRIVE_TO_CENTER instead of WAIT_TO_DRIVE in line 37.

I believe the three braces are OK. If you move your cursor in turn to each of those braces and type Ctrl-M, the editor will take you to their matching opening braces. They look fine to me.

As to the commented out case label, THAT does look strange, but I highly doubt that would cause the compile error in question. I don't know what the compiler will do with a chunk of code inside a switch statement without a case label. My guess is that it will simply be unreachable.

[Joe Ross]

Originally Posted by gwross

I believe the three braces are OK. If you move your cursor in turn to each of those braces and type Ctrl-M, the editor will take you to their matching opening braces. They look fine to me.

As to the commented out case label, THAT does look strange, but I highly doubt that would cause the compile error in question. I don't know what the compiler will do with a chunk of code inside a switch statement without a case label. My guess is that it will simply be unreachable.

When compiling with GCC, and an unmodified navigate.h, I only get one warning "warning: unreachable code at beginning of switch statement" So, the braces do all line up, and that commented out case caused a warning. It's possible that the problem is with that, and CrashZero should comment out that whole block. However, I would think that it's more likely that something was modified in navigate.h

[Kevin Karan]

indent...indent...indent

[Alan Anderson]

Originally Posted by gwross

I believe the three braces are OK. If you move your cursor in turn to each of those braces and type Ctrl-M, the editor will take you to their matching opening braces. They look fine to me.

Okay, I see the if and the nested switch now. The lost formatting of the post made it darn near impossible for me to tell what the structure of the code was supposed to be. (By the way, Ctrl-M just adds a new line when I type it.)

If the trouble is with an unprintable character in the source code, the problem character probably wouldn't have survived being pasted here. But I believe that the definition of LOST_TARGET_TIMEOUT in navigate.h is a likely culprit and should be investigated.

[Greg Ross]

Originally Posted by Alan Anderson

(By the way, Ctrl-M just adds a new line when I type it.)

Are you using the MPLAB IDE? I don't think I did anything special to enable this functionality. It's also on the "Edit" menu: "Match".

[Alan Anderson]

Originally Posted by gwross

Are you using the MPLAB IDE?

Um, no. I'm using Internet Explorer. I'm not anywhere near the computer we use to program the robot -- in fact, it's halfway to Chicago at the moment. I interpreted your mention of "the editor" as referring to viewing the HTML source of the page, where at least a little of the c file's formatting seems to be visible.