Device configuration

[user2009]

Without reading that configuration, your defines are wrong.

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#define _XTAL_FREQ = 20000000;

should probably be

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#define _XTAL_FREQ  20000000UL

I dont know what the intention of the other define, will it even compile?

[Dimebag]

I am lost again if its just a warning or, in fact I have a problem. (BlinkLED.c:4: warning: (111) redefining preprocessor macro "__delay_ms")

[Dimebag]

Thank you, user2009
May I ask why #define _XTAL_FREQ 20000000UL?

[user2009]

__delay_ms() is part of the library, you just need to include xc.h to use it. You redefine that function/macro by doing this

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define _delay_ms();

(you dont want to do that)

Edit: A macro is just text replacement.

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#define SOMETHING = 20;
unsigned char test = SOMETHING;

will be expanded to

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unsigned char test = = 20;;

You can see whats wrong with it that way.

As the others mentioned thats really basic stuff, get a tutorial/book and follow it.

[Dimebag]

#define delay_ms(); Complied. Why?

[Dimebag]

__delay_ms() is part of the library, you just need to include xc.h to use it.

if you read the posting I already included xc.h

As the others mentioned thats really basic stuff, get a tutorial/book and follow it.

[Dimebag]

If you know of any useful tutorials and books I should be reading, please let me know.

[Dimebag]

user2009, I just read all 6 posts you have done here. Help someone else. Thank you for your assistance.

[ric]

Without reading that configuration, your defines are wrong.

Code: Select all

#define _XTAL_FREQ = 20000000;

should probably be

Code: Select all

#define _XTAL_FREQ  20000000UL

There is nothing wrong with the original version.
It is used as part of a calculation inside another compiler defined macro.

I dont know what the intention of the other define, will it even compile?

I think it was an attempt to stop MPLABX putting a red squiggle under _delay_ms() when it is invoked. Yes, the define should NOT be there.
That is a bug in the MPLABX editor, it compiles just fine,

[user2009]

• Googlium is always mentioned
• Engscope has a nice one for PIC24
• "Programming 32-bit microcontrollers in C: exploring the PIC32" by Lucio Di Jasion is often mentioned when it comes to PIC32
• The C Book is a good online source
• C - frequently asked questions
• ...

You need to obtain some general basic knowledge of C language.