I have been following the YouTube tutorial by Novice Expert on Expert Mods: 3D Printer RGB LED Feedback here is the youtube link - [www.youtube.com]
I did everything he mentioned and I got my LED's working, but then I found that after using his code instead of the default one my Tempreture sensor for hotend and Bed is started fluctuating by around 20 degrees. so the ambient temperature before uploading code was 25 Celsius but after uploading code without heating anything it shows 28-29 Celsius and then it start to go up and down in between 15-40 Celsius.
now if I remove his code and use the default one this problem is gone, but then I lost that cool LED fade while heating the hotends which I really like to implement.
I figured out I thinks its the pin 5 and 6 which created this problem.
in the reference for analogWrite() function it says that these 2 particular pins can be an issue as they will not give complete 0 output on PWM and that may result the attached device to these pins not turning fully off. so as I tried avoiding these 2 pins the problem gone.
now I am using pin 4, 11 and 44 as these are the only available PWM pins I can find on ramps.