I was on my Survival world and was making piston doors. I since it's underground, I had to make it twist and turn. When I tried to add the repeater to stretch the redstone limit, when I flicked the lever, the pistons wouldn't move. I tried with less redstone and a shorter distance away from the pistons. It worked that time, but I need it longer. How do I make it stretch longer?
Add more than one redstone repeater. A redstone signal will only stretch for 15 blocks before disappearing, so add multiple repeaters to extend the travelling distance of the signal to the pistons.
Redstone signals have a strength between 1 and 15. If you place a torch and redstone dust next to it, that dust is at 15. Connect a second and that is strength 14. When you get to one, you need a repeater.
You can place all of your redstone dust trails and power from one end. Look at the dust, it indicates if it has a signal. Place a repeater where ever signal stops. Then continue down trail until the next one is needed.
Also, if your signal is going vertically up or down, use a torch tower instead of stairs. The signal amplifies itself so no repeaters are needed.