I wonder if someone could point me in the right direction for this.
I have about 30 leds arranged in pairs of two. When one of the pair is turned on, the other should be turned off.
I think I have a couple of options in terms of general approach both of which would need an external supply for the leds and appropriate resistors
Use a nano and Multiplex using 4 * 74HC595 giving me control of upto 32 leds, turning each of the pair off or on programmatically.
Use a mega with transistors or mosfets with each of the 30 leds being controlled by its own digital pin.
However, I suspect that there must be an approach from the electronics side where I can use the same digital pin to switch the state of both of the pair of leds, Unfortunately, I just cant see it
Can anyone offer any advice or pointers as to how I can do this.