I have no idea what you mean by this.
You do know you will only be able to get 7 colours from those RGB LEDs with that circuit don't you?
How much current dose the MCP23017 supply?
@Gerry48all combined outputs of one MCP23017 cannot exceed 150mA sink current andone port can sorce or sink a max of 25mathe MCP23017 has 16 Ports
How much current dose the MCP23017 supply? I don't think is will source or sink 20 mA. You need an additional buffer like ULN2803A connected to MCP23017.
There's also common anode and common cathode rbg leds. I would go with common anode.
Just to be clear, each MCP23017 should not have more than 5 leds on at a time.
The leds need about 20 mA each.
Rubbish, you haven't looked at the OP's actual circuit, all the LEDs can be on at once if he uses the resistors in his own schematic.
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.
Unless it's a very dark room, the leds won't be visible.
You have to draw that schematic better.
it does no harm having a power supply that is capable of more current than you need. It is often a good idea to to run them at only 80% full capacity.
in my case it would be like 40% of full capacity is that ok?
And just to be 100% sure to connect the supply to the right arduino port, you mean this one:
The only thing missing from that diagram now is the 0.1uF ceramic capacitor between the Vdd and Vss pins on each expander chip, and the missing 4K7 resistors pulling up the I2C lines.
0.1uF ceramic capacitor between the Vdd and Vss pins on each expander chip
what do you mean with between,
can you explain me what these components do?