PCA9685 LED Flickering


#1

I am using a Raspberry Pi 3 with a PCA9685. i have 4 sets of LED lights hooked up and i am able to adjust the brightness of each set. The LEDs are 3 watt lights used for Aquarius lights.The issue i am having is when the light are turned very low 10-20% they flicker or strobe. Does any one know how to fix this issue. Can the hz be adjusted? Maybe i can change the hz using some python code but im not sure where to start. What hz does Cayenne use as a default?


#2

Hello @branojeda good start is to reed the following publication here.


#3

Currently I am using meanwell ldd to provide a constant current. The set up i am using is common for an aquarium build. I do know the meanwell ldd are suppose to be flicker free but must run at 100-1k hz. When using a pca9685 on cayenne what is the default frequency. Is it 60 hz?. How do i change the hz? I thinks this would help me understand if i need to make a change to the circuitry.


#4

I can’t answer this question. Hope somebody to join in the conversation.


#5

@eptak would probably know the Hz. If not I can get mine out and test with my multimeter.


#6

@branojeda I’m reading 54.3Hz so that explains why your lights are flickering. Unfortunately unless you use the MQTT API there is no way to change the value of the Hz.