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wmeade
Joined: 08 Sep 2003
Posts: 16
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| Custom LCD Characters |
 Posted: Fri Sep 12, 2003 8:38 am |
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| I would like to create a custom LCD character to display on my 4x20 LCD. This was rather easy in PBP, but appears to be more complicated in PICC. I searched the forum and found one message that pertained to my question but it was using functions that are not in the LCD.C, which is what I am using. Should I be using a different driver or will the LCD.C work for loading a custom character into the CG_RAM on the Display? Thanks in advance........ |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Fri Sep 12, 2003 9:33 am |
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Read the datasheet for the LCD controller that you are using. It is pretty simple to implement you just have to know what to do.
Here is one I wrote a while back. I think you should be able to the the 'lcd_send_byte' from LCD.C with this.
| Code: |
#define LCD_COMMAND 0
#define LCD_DISPLAY 1
#define LCD_CG_RAM 0x40
/****************************************************************************
* NAME: Store_Custom_Char
* DESCRIPTION: Stores the custom characters in the CGRAM of the LCD Display
* PARAMETERS: none
* GLOBALS: none
* RETURN: none
* ALGORITHM: none
* NOTES: none
*****************************************************************************/
void Store_Custom_Char(void)
{
LCD_Write(LCD_COMMAND, LCD_CG_RAM);
/******************************* 'É' **************************************/
LCD_Write(LCD_DISPLAY,0x02); /* X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x10); /* X */
LCD_Write(LCD_DISPLAY,0x1E); /* XXXX */
LCD_Write(LCD_DISPLAY,0x10); /* X */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x00); /* */
/******************************* 'Ç' **************************************/
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x10); /* X */
LCD_Write(LCD_DISPLAY,0x10); /* X */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x0C); /* XX */
/******************************* 'À' **************************************/
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x0A); /* X X */
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x00); /* */
/******************************* 'Ô' **************************************/
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x0A); /* X X */
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x00); /* */
/******************************* 'é' **************************************/
LCD_Write(LCD_DISPLAY,0x02); /* X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x11); /* X X */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x10); /* X */
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x00); /* */
/*************************** Down arrow ***********************************/
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x15); /* X X X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x00); /* */
/*************************** Up arrow *************************************/
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x15); /* X X X */
LCD_Write(LCD_DISPLAY,0x0E); /* XXX */
LCD_Write(LCD_DISPLAY,0x04); /* X */
LCD_Write(LCD_DISPLAY,0x00); /* */
/*************************** Not Used *************************************/
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
LCD_Write(LCD_DISPLAY,0x1F); /* XXXXX */
} |
Last edited by Mark on Sun May 22, 2005 8:59 pm; edited 1 time in total |
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wmeade
Joined: 08 Sep 2003
Posts: 16
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| Posted: Fri Sep 12, 2003 12:44 pm |
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Thanks for the quick response mark. I was able to load and display my custome cursor.
Below is how I loaded it and then displayed it for anyone that may be doing the same thing using LCD.C.
// Load Custome Cursor Into LCD CG RAM
lcd_send_byte(0,0x40); // (0 = command mode) write to LCD CG Ram location 0
lcd_send_byte(1,0x08); // (1 = display mode) load cursor line 1 of 8
lcd_send_byte(1,0x0C); // (1 = display mode) load cursor line 2 of 8
lcd_send_byte(1,0x0E); // (1 = display mode) load cursor line 3 of 8
lcd_send_byte(1,0x0F); // (1 = display mode) load cursor line 4 of 8
lcd_send_byte(1,0x0E); // (1 = display mode) load cursor line 5 of 8
lcd_send_byte(1,0x0C); // (1 = display mode) load cursor line 6 of 8
lcd_send_byte(1,0x08); // (1 = display mode) load cursor line 7 of 8
lcd_send_byte(1,0x00); // (1 = display mode) load cursor line 8 of 8
// Display Custome Cursor on LCD from LCD CG RAM Location 0
lcd_send_byte(1,0); // (1 = display mode) (0 = CG RAM location) |
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Bryan
Joined: 23 Apr 2005
Posts: 73
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| Posted: Fri May 20, 2005 11:11 am |
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| Where did you put this code in your main program to get it to load and display your custom cursor? I tried doing this right after lcd_init() in main but it doesn't display anything - Does this need to be inside the lcd_init() function? |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Fri May 20, 2005 11:55 am |
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These only store the data in the LCD. Take a look at the datasheet. You access the custom characters with a code (0-7 in this case).
| Code: |
printf(lcd_putc,"This is custom char 2 \1");
printf(lcd_putc,"This is the fourth custom char \4");
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The first custom address is stored at 0 so that one is a bit tricky since \0 also signals the end of a string. |
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Bryan
Joined: 23 Apr 2005
Posts: 73
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| Posted: Fri May 20, 2005 12:15 pm |
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| Thanks for the help Mark! When I tried this out, I needed to clear the display after calling the Store_Custom_Char() function before I was able to get anything to output. Do you know why this is? Also, you were right \0 doesn't work correctly so I may just store the 2 custom characters that I need for my project in positions 1 and 2 since they work fine. |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Fri May 20, 2005 2:50 pm |
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| You can make the 0 char work but probably not in a printf(). |
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CharlieGill
Joined: 29 Nov 2004
Posts: 15
Location: northeast georgia
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| Posted: Sun May 22, 2005 7:16 pm |
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If you encode your custom characters using binary constants it makes it easier to visualize what the character looks like.
0b0000100
0b0001110
0b0010101
0b0000100
0b0000100
0b0000100
0b0000000
Charlie |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Sun May 22, 2005 9:00 pm |
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I added the code formating to my orginal post. I think they stand out pretty well  |
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