Output of user characters on the T6963C LCD screen.

[MechanicVV]

Good afternoon. Tell me please. When trying to output custom characters from const char font[256][8], garbage appears on the screen. How to solve this problem?

const char font[256][8] =
        { { 0b11111, 0b10000, 0b10000, 0b11110, 0b10001, 0b10001, 0b11110, 0b00000 },
          { 0b11111, 0b10000, 0b10000, 0b10000, 0b10000, 0b10000, 0b10000, 0b00000 },
          { 0b00110, 0b01010, 0b01010, 0b01010, 0b01010, 0b01010, 0b11111, 0b10001 },
          { 0b10101, 0b10101, 0b10101, 0b01110, 0b10101, 0b10101, 0b10101, 0b00000 },
          { 0b01110, 0b10001, 0b00001, 0b00110, 0b00001, 0b10001, 0b01110, 0b00000 },
          { 0b00111, 0b01001, 0b01001, 0b01001, 0b01001, 0b01001, 0b10001, 0b00000 },
          { 0b11111, 0b10001, 0b10001, 0b10001, 0b10001, 0b10001, 0b10001, 0b00000 },
          { 0b10001, 0b10001, 0b10001, 0b01111, 0b00001, 0b10001, 0b01110, 0b00000 }
        };

void read_stat_lcd() {
    while ((Lcd_com & 0x03) != 0x03)
        ;
}

void write_com(uint8_t com) {
    read_stat_lcd();
    WriteCommand(com);
}

void write_dat(uint8_t dat) {
    read_stat_lcd();
    WriteData(dat);
}

void T6963_WriteDisplayData(unsigned char x) // Writes display data and increment address pointer
{
    write_dat(x);
    write_com(T6963_DATA_WRITE_AND_INCREMENT);
}

void Set_Address_pointer(uint16_t addr) {
    write_dat(addr & 0xff);
    write_dat(addr >> 8);
    write_com(0x24);
}

void Set_Offset_Register(uint16_t addr) {
    write_dat(addr & 0xff);
    write_dat(addr >> 8);
    write_com(0x22);
}

void glcd_clear_graph() {
    Set_Address_pointer(T6963_GRAPHIC_HOME);
    for (uint16_t i = 0; i < T6963_GRAPHIC_SIZE; i++) {
        write_dat(0);
        write_com(T6963_DATA_WRITE_AND_INCREMENT);
    }
}

void glcd_clear_text() {
    Set_Address_pointer(T6963_TEXT_HOME);
    for (uint16_t i = 0; i < T6963_TEXT_SIZE; i++) {
        write_dat(0);
        write_com(T6963_DATA_WRITE_AND_INCREMENT);
    }
}

uint16_t add = 0;
void T6963_DefineCharacter(uint8_t charCode, const char (*defChar)[8]) // Write single char pattern to character generator area of display RAM memory
{

    add = charCode;
    add = add << 3; //Character code 00h to 80h assign External character generator, when
                    //External generator mode.
    Set_Address_pointer(add);

    for (uint8_t i = 0; i < 8; i++) //The process of writing user characters to CG RAM
        T6963_WriteDisplayData(defChar[charCode][i]);

    Set_Address_pointer(charCode); //Setting the initial position of the first sign on the LCD screen
    write_dat(charCode);                                 //Writing data
    write_com(T6963_DATA_WRITE_AND_NONVARIALBE); //Writes display data and Non-variable address pointer

}

void lcd_init(void) {
    HAL_Delay(10);
    HAL_GPIO_WritePin(GPIOC, GPIO_PIN_4, RESET);
    HAL_Delay(10);
    HAL_GPIO_WritePin(GPIOC, GPIO_PIN_4, SET);       //Hardware reset of the LCD
    HAL_Delay(10);

    write_com(T6963_MODE_SET | T6963_MODE_CG_RAM); //Setting the operating mode external CG RAM

    Set_Address_pointer(T6963_GRAPHIC_HOME);
    write_com(T6963_SET_GRAPHIC_HOME_ADDRESS);
    Set_Address_pointer(0x001E);
    write_com(T6963_SET_GRAPHIC_AREA);

    Set_Address_pointer(0);
    write_com(T6963_SET_TEXT_HOME_ADDRESS);
    Set_Address_pointer(0x0028);
    write_com(T6963_SET_TEXT_AREA);

    Set_Offset_Register(0);

    Set_cursor(0, 0);

    write_com(
            T6963_DISPLAY_MODE | T6963_TEXT_DISPLAY_ON
                    | T6963_GRAPHIC_DISPLAY_ON | T6963_CURSOR_DISPLAY_ON
                    | T6963_CURSOR_BLINK_ON);

}

int main(void) {
    lcd_init();
    glcd_clear_text();
    glcd_clear_graph();

    for (uint8_t k = 0; k < 8; k++)
    {
        T6963_DefineCharacter(k, font); //Writing custom characters from the "font" array
                                        //and displaying these characters on the screen
    }
}

 

[Ian Rogers]

Two things.. A) that appears to be the same character printed over and over. This is weird as the code doesn't have a forever loop so it'll keep rebooting and clearing

The first 8 are as you have defined them. So the code is working..

place a forever loop after the for loop so you can see what prints.

while(1) {} <<<--- and it'll halt here so you can see.