TLC5947 + Piranha RGB; How to deal with lower voltage for Red?

Other Hardware LEDs and Multiplexing
2

paulo999:
So, I have my 5947s running nicely with some plain old single colour LEDs.

Soon arriving is a bag of Piranha Super Flux RGB LEDs. Although the retailer documents them as being 3.2-3.6v on all three colours, I suspect that in reality (in common with all the other Piranhas out there), that the Red is in fact a lower range, say 1.8 - 2.2v.

With the 5947 being a constant current sink, I was really hoping to avoid a plethora of resistors. Am I basically saddled with feeding in, say, 3.5v, and then inlining a resistor to the Red to bring it down to say 2.0v?

Constant current means what it says.

paulo999:
All ideas welcome. :slight_smile:

Learn Ohms law.

Much more importantly, believe it.