Calling with a reference of union

[Andrew-miksys]

Hi,
I'm trying to create buffer writing function.

[Ttelmah]

Exactly the same way as with any other variable. So:

void InsertInteger(union LCD_BUF val) {

}

Then call this with (for your first variable shown):

InsertInteger(disp1);

While inside the routine, use (for example)

val.icons

Best Wishes

[Andrew-miksys]

Thanks,
I'm not sure but this way will be created local copy of union wich be exist only inside function body. So any operation has no effect after end of function. Am I right?

[Ttelmah]

Yes.
If you want to reference the external union, thre are two routes:
1) Declare the variables as global (declare them outside the body of the main function). Then you can refer to these anywhere.
2) Pass a pointer to the external declaration. For this:

void InsertInteger(union LCD_BUF * val) {

}
Note the '*', which says thatthis value is a 'pointer to' a value of this type.
Call this with:

InsertInteger(&disp1);

Note the '&', which means pass the address of this.
Then in the function, use:

val->icons

Note that unions, and structures are identical in their syntax here, both allowing the -> shortcut to access a member,rather than having to use the * to 'dereference' the pointer.
A union, is actually a type of structure in C, which has two (or more) different sets of names, referencing the same data.

Best Wishes

[Andrew-miksys]

Thanks!
I tested it berofe but forgot of -> operator
It works of course.