w_1:(continued)

This is really valuable information.

When I tried to connect a variable resistor I was almost lost. It has 3 legs.
I could not figure out which is for power which is for data and which is for ground?

After several trial and error, I got a help from Todd.

The secret is
... power, data, ground from the left. You can swich power with ground. But the LED's response will swich too.

Already knew it?