Contd - RGB LEDs and Adafruit 16-Channel 12-bit PWM/Servo Dr Moderators: adafruit_support_bill, adafruit

[adafruit_support_bill]

You should not need any extra resistors since you can control brightness of the LEDs via PWM.

[pobo123]

Even using the V+ pin with the PWM and not the Ground pin? Also, my three LEDs (as I explained in an earlier post) have a common anode. Does this make any difference please - can I still get away without extra resistors?

[pobo123]

The reason I ask my last question is because I seem to be getting conflicting answers on this forum but it could be due to not explaining the setup clearly.

[adafruit_support_bill]

Also, my three LEDs (as I explained in an earlier post) have a common anode.

The PCA9685 is not designed for driving common anode LEDs.

[pobo123]

Ok. So what do I do to get around that? I am sure it is still possible.

[pobo123]

And without burning out my LEDs

[adafruit_support_bill]

To drive a common anode LED you could connect the anode to 5v and each of the cathodes to the PWM output pin. No additional resistors should be necessary.

In your code, you will need to reverse all the logic: At 100% duty cycle, the LEDs will be off (or at least very dim). If you decrease the duty cycle, it will make them brighter.

[pobo123]

Thank you. I will try / go with that :-)