I want to control two RGB LEDs with only 4 pins.
I have attached a schematic of what I had in mind.
RED, GREEN, BLUE and CONTROL come from the microcontroller.
When CONTROL is low, the common cathode LED will display its colour depending on the state of RED GREEN and BLUE pins.
When control is high, the common anode LED will display its colour depending on the states of the other three pins, but this time inverted.
With this circuit I can easily switch between both LEDs so fast that they appear to be controlled independently.
(I am also aware that there will be 3 LEDs worth of current going through the control pin and when I move up to a higher duty cycle I will need transistors or an opamp to beef up the power).
That is my understanding of it...
Nigel you now have me excited, Im fully expecting you to reply with a much simpler circuit that allows me to use 2 common anode LEDs.
I await your response...