uln2003 and rgb led

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi... How do I hook-up a single rgb led to a ULN2003... It has a common ground.

I've got arduino pins 9,10,11 going to pins 1,2,3 of the uln...

I wanted to plug the led into 14,15,16.

I've tried plugging in the common ground to 14,15,16 and the rgb pins to +5 - which works - but I'm it isn't right - I'm also not able to get the full rgb effect...

Any help would be appreciated...

I know I'm doing something stupid...

2

Common anode to 5V. Each cathode to its own resistor, other end of resistor to a separate output of the 2003, then inputs of 2003 to the outputs of the arduino.

3

Hi... My rgb has a common cathode....

4

That is unusual for an RGB LED. If that is true then you can't use a 2003 to drive it because it only sinks current and you need to source it.