CODEWITHSUNDEEP
cembeddedstm32nucleo
VynxZ
VynxZ

Reputation: 11

LED 8x8 DotMatrix STM32

I'm using STM32 Nucleo-L053R8

I can display a single char in 8x8 dot matrix. But my problem is how can I make a string scroll to left or right direction?

Here is the code for displaying single char in 8x8 Dot Matrix:

uint8_t myfont[36][8]={

{0x70>>2,0x88>>2,0x98>>2,0xA8>>2,0xC8>>2,0x88>>2,0x88>>2,0x70>>2}, // 0
}

dotmatrix_put(myfont[0]);

void dotmatrix_put(uint8_t *data){
 for(uint8_t i=0;i<8;i++){
        dotmatix_buf[i]=data[i];
    }
}

Hoping for the help, Thank you in Advance!

Upvotes: 1

Views: 569

Answers (1)

ThongDT
ThongDT

Reputation: 189

Assuming that the array you defined:

    uint8_t myfont[36][8]

with [8] is define for column.

The concept of scrolling left/right is by display another frame with shifting the column. For example:

  • First frame you show:

      [col0, col1, col2, col3, col4, col5, col6, col7]

  • Second frame you show:

      [col1, col2, col3, col4, col5, col6, col7, <empty>]

<empty> is for clearing the last column after shift. If you prefer rotate, it should be col0.

Align with your code (just example for left/right shift, you could extend for other cases), some minor change as following:

    void dotmatrix_put(uint8_t *data, int8_t shift_col)
    // shift_col is number of column to shift: 0 = no shift, -1 for shift left 1, 1 for shift right 1
    {
        uint8_t max = 7;
        uint8_t min = 0;
        int8_t start_col = 0;
        
        if (shift_col > 0)
        {
            min = min + shift_col;
        }
        else
        {
            max = max + shift_col;
            start_col = -shift_col; // get the positive or 0 number
        }
        
        for(uint8_t i=0;i<8;i++)
        {
            if (i >= min && i <= max)
            {
                dotmatix_buf[i]=data[i + start_col];
            }
            else
            {
                dotmatix_buf[i] = 0;
            }
        }
    }

Upvotes: 0

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