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_olaf_
Joined: 24 Feb 2005
Posts: 32
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| How to access string in struct? |
 Posted: Sat Oct 01, 2016 2:55 pm |
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Hi,
I want to set up a LCD menu for my new project. I read a lot of examples but at the end I couldn't implement something that worked.
I found an example which looked like it would fulfill my needs, but I only get nonsense on my LCD. The LCD output itself works fine.
I found following Code
| Code: |
#define Menu_Entries 10
enum ids{_BEGIN,_,_MAIN1,_SUBMENU_1A,_SUBMENU_1B,_MAIN2,_SUBMENU_2A,_SUBMENU_2B,_MAIN3,_SUBMENU_3A,_SUBMENU_3B};
const struct LCD_Menu
{
int8 MenuID;
int8 SubMenu;
char MenuName[16];//17
};
const struct LCD_Menu Menu[Menu_Entries] =
{
{_,_BEGIN,""},
{_MAIN1,_BEGIN,"Mainmenu 1"},
{_SUBMENU_1A,_MAIN1,"Sub_Menu 1a"},
{_SUBMENU_1B,_MAIN1,"Sub_Menu 1b"},
{_MAIN2,_BEGIN,"Mainmenu 2"},
{_SUBMENU_2A,_MAIN2,"Sub_Menu 2a"},
{_SUBMENU_2B,_MAIN2,"Sub_Menu 2b"},
{_MAIN3,_BEGIN,"Mainmenu 2"},
{_SUBMENU_3A,_MAIN3,"Sub_Menu 3a"},
{_SUBMENU_3B,_MAIN3,"Sub_Menu 3b"}
};struct LCD_Menu MenuPointer[3];
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I don't know if I have understood the code, but I don't think so.
In the following line | Code: | | const struct LCD_Menu ... |
the types of the entries in the following
| Code: | const struct LCD_Menu Menu[Menu_Entries] =
{ |
are declared. Is this right?
In my main I wanted to write the MenuName to the LCD.
| Code: | | printf(LCD_char,"%s",MenuPointer[1].MenuName); |
But all I get on the LCD are cryptic characters. The printf(...) does work. I have some other parts in the program where I can write to the LCD without any problem.
How can I write the string from the const struct LCD_Menu to my LCD? I doesn't make a difference if I use
printf(LCD_string,"%s",...) or printf(LCD_char,"%c",...)
BR
Edit: Changed subject |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sat Oct 01, 2016 4:35 pm |
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In the following line, you are creating empty RAM-based structures.
They have to be initialized with data.
| Quote: | | struct LCD_Menu MenuPointer[3]; |
To initialize the RAM-based structures in the MenuPointer array, you
can copy the const data into it. Add the code shown below:
| Quote: |
void main()
{
int8 i;
for(i = 0; i < 3; i++)
{
MenuPointer[i] = Menu[i];
}
printf(LCDchar, "%s", MenuPointer[1].MenuName);
while(TRUE);
} |
If it still doesn't work, it could be a compiler version issue as I point out
near the end of this thread:
http://www.ccsinfo.com/forum/viewtopic.php?t=55193
Always post your compiler version. |
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_olaf_
Joined: 24 Feb 2005
Posts: 32
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| Posted: Sun Oct 02, 2016 1:54 am |
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Sorry I forgot. Compiler Version is 5.064
Thank you very much PCM_Programmer.
So I have to copy the data I want to use into the MenuPointer.
e.g. if I want to get the 6 values of the struct array I have to copy
| Code: |
MenuPointer[5] = Menu[5]; |
I tried this from your link
| Code: |
for(i = 0; i < ALL_MENU; i++)
{
MenuPointer[k] = MenuTest[i];
printf("> %s \r", MenuPointer[0].MenuName);
}
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This doesn't work propper, but I think it is because I copied the data into the MenuPointer in the beginning of main and then used it later in the program.
| Code: |
void main()
{
//do some initializaton
...
...
for(i = 0; i < ALL_MENU; i++)
{
MenuPointer[k] = MenuTest[i];
}
...
...
//do somthing else
...
...
printf("> %s \r", MenuPointer[0].MenuName);
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Copying the data into the MenuPointer just in front of the printf(...) does work.
Best Regards |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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Ttelmah
Joined: 11 Mar 2010
Posts: 19553
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| Posted: Sun Oct 02, 2016 7:27 am |
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| As a comment, think about it. If it works putting the data in 'close' to where you use it, but not when you fill it earlier, it implies _something_ you are doing between these points, is changing the data...... |
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_olaf_
Joined: 24 Feb 2005
Posts: 32
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| Posted: Mon Oct 03, 2016 6:21 am |
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Now it works. I had a little code snippet in front of the code.
Thanks for your help. |
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avatarengineer
Joined: 13 May 2013
Posts: 51
Location: Arizona
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| constant strings for LCD |
| Posted: Mon Oct 03, 2016 11:19 am |
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I found the most robust means to create menus, templates for LCDs
was to list strings as constants such as in a #define then load a selected page into an array using such as:
| Code: |
strcpy(page.line[0].field,Line91);
strcpy(page.line[1].field,Line92);
strcpy(page.line[2].field,Line93);
strcpy(page.line[3].field,Line94); |
A slicker approach:
I now load the strings directly as programmed into Flash
at fixed addresses then just read what I need.
Much less code. Simple read_program_eeprom
using memory locations as pages of lines to read into data structure.
ok?  |
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avatarengineer
Joined: 13 May 2013
Posts: 51
Location: Arizona
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| Menus in ROM |
| Posted: Mon Oct 03, 2016 11:29 am |
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Forgot to add this:
| Code: | #DEFINE EndofMemory 0x4000 // Outside End of ROM address
#DEFINE MemoryBlock 0x0040 // allocated space per log 64 byte limit
#DEFINE LCD_Line1 "blah blah ..."
#DEFINE LCD_Line2 "more blah blah ..."
#DEFINE COMMENT1MEM EndofMemory-(1*MemoryBlock) // LOCATE STRING INFO
#DEFINE COMMENT2MEM EndofMemory-(2*MemoryBlock) // LOCATE STRING INFO
#ROM COMMENT1MEM={LCD_Line1}
#ROM COMMENT2MEM={LCD_Line2} |
The compiler does all the work,...
then just read out as needed.
Enjoy
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