c - Creating a loop to display countdown on LCD screen -

i'm writing function counts down 3 on microprocessor , lcd screen.

void countdown() { _delay_ms(1000); draw_string("3",40,20); _delay_ms(1000); clear(); draw_string("2",40,20); _delay_ms(1000); clear(); draw_string("1",40,20); _delay_ms(1000); clear(); } 

i tried it's inefficient , bad practice.

how write correctly?

use for loop:

for (char c = '3'; c > '0'; c--) {     // convert c ascii value , null-terminate     char str[2] = { c, '\0' };      // draw string     draw_string(str, 40, 20);     _delay_ms(1000);     clear(); }