st7920_spi_write
st7920_spi_write(st7920->spi, SET_DISPLAY_ON, NULL, 72, err);
st7920_spi_write(st7920->spi, SET_DISPLAY_CLEAR, NULL, 1600, err);
st7920_spi_write(st7920->spi, SET_DISPLAY_OFF, NULL, 72, err);
st7920_spi_write(st7920->spi, SET_BASIC_INSTRUCTION_SET, NULL, 72, &err);
st7920_spi_write(st7920->spi, SET_GRAPHICS_DISPLAY, NULL, 72, &err);
st7920_spi_write(st7920->spi, SET_DISPLAY_CLEAR, NULL, 1600, &err);
st7920_spi_write(st7920->spi, SET_GDRAM_ADDRESS, &i, 72, &err);
st7920_spi_write(st7920->spi, SET_GDRAM_DATA, line_buffer, 72, &err);
st7920_spi_write(st7920->spi, SET_DISPLAY_CLEAR, NULL, 1600, &err);