@Grumpy_Mike I'm very grateful for clarifying these issues.
I hope these will be my last questions:
- Im still not 100% sure about how to connect the power supply with my circuit and wanted to ask wether the following rough draft with only 2 Expanders of what Im thinking is right or wrong:
- Do I need a 5V 2.5A adapter or less ampere because:
Grumpy_Mike: With a 330R current limiting resistor the the red LED is drawing 9mA and the green and blue 6mA each. So that is 21mA per RGB LED. So for 5 RGB LEDs on one port it is only supplying 105mA.
- If I connect an adapter via USB with this: https://www.flikto.de/products/usb-type-a-female-breakout (I hope it's a suitable part) Then how do I connect my arduino with it?(what kind of wire/port or component do I need to buy) @Gerry48 I already have RGB LEDs with a common cathode, but they work fine with 330ohm resistors Thanks for helping me once more