problems with display 16x2

[Feo]

Hi,
I'm using an EasyPic7, a pic 16f876 with a 4Mhz crystal and the lcd display is a WINSTAR model WH1602B-TMI-ET#(from EasyPic7).
I need pictograms to be showen on display , like in pic.№1 of the attachment.
I'm trying to make code work with one symbol - symbol №0 in pic №1.

Code: Select all

const unsigned short Untitled5x8[] = {
        0x1F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  // Code for char num #0
               };
void InitHD44780CustomChars()
{
  char i;
  LCD_Cmd(64);
  for (i = 0; i <= 7 ; i++)
    LCD_Chr_Cp(Untitled5x8[i]);
  LCD_Cmd(_LCD_RETURN_HOME);
}
...............................
void main(){
while (1){
Lcd_Cmd(_LCD_CLEAR);
Lcd_Cmd(_LCD_CURSOR_OFF);
delay_ms(500);
InitHD44780CustomChars();
delay_ms(500);
}

}

This variant shows nothing on display.
But, when changing code (adding {} to circle for):

Code: Select all

void InitHD44780CustomChars()
{
  char i;
  LCD_Cmd(64);
  for (i = 0; i <= 7 ; i++)                {
    LCD_Chr_Cp(Untitled5x8[i]);
  LCD_Cmd(_LCD_RETURN_HOME);   }
}

The first place has line at top on display, as is needed.
For getting the second line we change the code:

Code: Select all

const unsigned short Untitled5x8[] = {
        0x1F, 0x1F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  // Code for char num #0
               };

after programming the controller indication is not changed. When the board is switched off and then switched on again the monitor shows random elements in the first place.
Delete {} from circle FOR, program - nothing on the monitor. When programming with {} - two lines are shown.

What do you think the matter is?.
Don't know as well what the command LCD_Cmd(64) is for.

[Seniorlemuren]

You could do it like this:

Code: Select all

const char character_zero[] = {0x1F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};    //char  -

void CustomChar0(char pos_row, char pos_char) {
  char i;
    Lcd_Cmd(64);
    for (i = 0; i<=7; i++) Lcd_Chr_CP(character_zero[i]);
    Lcd_Cmd(_LCD_RETURN_HOME);
    Lcd_Chr(pos_row, pos_char, 0);
}
...............................
void main(){
              // All stuff you do here depending on uC comes first

    .
    .
     Lcd_Init();
     Lcd_Cmd(_LCD_CLEAR);               // Clear display
     Lcd_Cmd(_LCD_CURSOR_OFF);          // Cursor off
     Lcd_Out(1,1,"My char zero") ;
     CustomChar0(2,1);                 //Lcd  row #2, pos #1
}

Or if you have several custom char, you could do it like this:

Code: Select all

const char character_zero[] = {4,0,14,1,15,17,15,0};    //char å
const char character_one[] = {10,0,14,1,15,17,15,0};    //char ä
const char character_two[] = {10,0,14,17,17,17,14,0};   //char ö
const char character_three[] = {4,14,17,17,31,17,17,0}; //char Å
const char character_four[] = {10,14,17,17,31,17,17,0}; //char Ä
const char character_five[] = {10,14,17,17,17,17,14,0}; //char Ö

void load_char() {
  char i;
    Lcd_Cmd(64);
    for (i = 0; i<=7; i++) Lcd_Chr_CP(character_zero[i]);
    Lcd_Cmd(72);
    for (i = 0; i<=7; i++) Lcd_Chr_CP(character_one[i]);
    Lcd_Cmd(80);
    for (i = 0; i<=7; i++) Lcd_Chr_CP(character_two[i]);
    Lcd_Cmd(88);
    for (i = 0; i<=7; i++) Lcd_Chr_CP(character_three[i]);
    Lcd_Cmd(96);
    for (i = 0; i<=7; i++) Lcd_Chr_CP(character_four[i]);
    Lcd_Cmd(104);
    for (i = 0; i<=7; i++) Lcd_Chr_CP(character_five[i]);
}


void main() { 
              // All stuff you do here depending on uC comes first

    .
    .
     Lcd_Init();
     load_char();
     Lcd_Cmd(_LCD_CLEAR);               // Clear display
     Lcd_Cmd(_LCD_CURSOR_OFF);          // Cursor off
     Lcd_Out(1,1,"All my char") ;
     Lcd_Chr(2,1,0);
     Lcd_Chr_CP(1);
     Lcd_Chr_CP(2);
     Lcd_Chr_CP(3);
     Lcd_Chr_CP(4);
     Lcd_Chr_CP(5);

}

[Feo]

thanks a lot!Your code is correct, but I can't get why it works.
"Lcd_Chr(pos_row, pos_char, 0);" why we need to add this function. If i get right, it just indicates the symbol's place.
Why we put zero into this place?

[Seniorlemuren]

If you look at the LIbrary for LCD you can se the prototype for Lcd_Chr

Code: Select all

void Lcd_Chr(char row, char column, char out_char);

You give the row and column for the char 0. char 0 is your custom char. If you look at the next example with more than one char you maybe understand how it works.

You ask earlier why this "Lcd_Cmd(64);" is for. That is the RAM address for the custom char. Next custom char it to be in RAM address 72 and so on.