Cause: You are calling u8x8.clear() or u8x8.refresh() too often.
Fix: Use u8x8.setCursor(x,y) and overwrite specific characters. Because the display is page-addressed, overwriting one 8x8 block does not disturb the rest.
Because microcontrollers are resource-constrained, u8x8 fonts store data vertically or horizontally depending on the display controller. For example, an OLED display (SSD1306) uses a vertical page layout. The 8 bytes for the letter 'A' might represent Column 0, Pages 0-7. u8x8 fonts
The beauty of u8x8 fonts is that this rendering math is simple. To draw an 'A' at column 5, row 2, the library simply copies 8 bytes of pre-defined font data to the display's memory at a specific offset. No bit-shifting, no clipping, no complex math. Cause: You are calling u8x8
Do not try to scale U8x8 fonts manually with loops. Use the pre-scaled versions (e.g., _2x2_r or _3x3_r) or use the u8x8.draw2x2String() function, which duplicates pixels for you. The beauty of u8x8 fonts is that this