two leg, bi-color led control.

Other Hardware LEDs and Multiplexing
6

johnwasser:
Are 'arduino 1' and 'arduino 2' just two pins on the same Arduino?

Is the "-5V" really MINUS five volts? If so, why?

Why not just connect the LED directly to two data pins:
Pin2 ----- Resistor----- LED----Pin3

Then you will get one color with Pin2 HIGH and Pin3 LOW and the other color with Pin2 LOW and Pin3 HIGH.

Hello , thank you very much for your reply. : )

I would really like to use only two pins for this. wow, the footprint would be so much smaller.

My mega ardunio will be powered via a 12v regulator and there is a "+5v" reg available also. However I need to power:

12 bi colour leds tactile switches, (only 6 will be on at a time of course)
15 single colour leds. ( < these could be powered via transistors instead)
I have 2 shift registers running a dual segment display. ( from only 3 pins of course)

I was fearing that I may overheat the arduino? i presume the above would be approx 500 ma. So I thought to use transistors here to keep the arduino cool.

do you think I would be o.k with the above ? maybe i should just use transistors on the single leds instead? that would certainly help.

: )