HI2C question - Is this allowed?

[MBB]

I'm using version 0.98.01 with an 18F4550.

This below code is not working.

If var = 1 Then
#define HI2C_BAUD_RATE 400
End If
'
If var = 2 Then
#define HI2C_BAUD_RATE 100
End If

Does GCB allow #define statements to be used like this?

[Anobium]

You assumption   is correct. All #define are processed prior to ordering of conditions.

You can use a script.

[stan cartwright]

Dim var as word : var=400 : HI2C_BAUD_RATE var assembles if useful

[Anobium]

This method WILL NOT work.

** Dim var as word : var=400 : HI2C_BAUD_RATE var assembles if useful**

Why? the script that calculates the correct regiser settngs will NOT read the variable. You must use a Constant. I have not assessed the impact of using a script so I cannot comment. But, using a variable will fail to set the appropiate registers correctly.

[Chris Roper]

It may not produce a compiler error but it certainly will not work.
You are trying to access a runtime variable with a compile time statement.

The preprocessor will ignore the undknown portion.
That holds for all compilers not just GCBASIB.

On Mon, 5 Mar 2018 11:33 pm stan cartwright, stanleyella@users.sourceforge.net wrote:

Dim var as word : var=400 : HI2C_BAUD_RATE var assembles if useful

HI2C question - Is this allowed?
https://sourceforge.net/p/gcbasic/discussion/579126/thread/b515fe05/?limit=25#2a1f

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[MBB]

Thanks!

[Anobium]

Pleasure.

You can use a constant #define myI2CSpeed 100 then change use #define HI2C_BAUD_RATE myI2CSpeed

Anobium

[stan cartwright]

So you can redefine a contant with another constant not a variable and that would work with if then? Doesn't seem like if it's a #define.

[Anobium]

It   is a   Define and   it works.

[Chris Roper]

So you can redefine a contant with another constant not a variable and
that would work with if then?

You can't use if.
You may be thinking of #ifdef
That is a preprocessor derivative that works with #define
But only in the preprocessor at compile time
The #derivatives nolonger exist at runtime.