Called function that loops depending on the argument

Question

I have a function LED_MAIN() whose work is to light up LEDs by calling upon another function LED_MAIN_LINE() which is private to it, meaning when I am

Answer 1

LED_NO_UP and LED_NO_DOWN are 0. So the for loops in your code are never executed because i < 0 is not possible when i = 0.

Also you have 1<20 in the first for loop.