int x = 20, y = 30;
int dx = 1, dy = -1;

void loop()
{
    // wait for frame timing to maintain constant FPS
    while(!$next_frame())
        ;
        
    // draw some text with one of the built-in fonts
    $draw_text_P(29, 36, "Hello World!");
        
    x += dx;
    y += dy;
    if(x < 0 || x > 120) { dx = -dx; x += dx * 2; }
    if(y < 0 || y >  56) { dy = -dy; y += dy * 2; }
    
    // Draw an 8x8 sprite with a sprite literal: sprites{ WxH [pixels] }
    //     '-' is a transparent pixel
    //     '.' is a black pixel
    //     all other non-whitespace characters are white pixels
    $draw_sprite(x, y, sprites{
        8x8
        --XXXX--
        -X....X-
        X......X
        X......X
        X......X
        X......X
        -X....X-
        --XXXX-- }, 0);
    
    // push display buffer to display and clear it
    $display();
}

void main()
{
    $set_text_font(FONT_ADAFRUIT);
    while(true)
        loop();
}