Driving a dual Anode LED

[made2hack]

Hello all,

So I have a dual color LED (Red + Green) that share a common GND. So it is essentially 2 anodes (1 for each colour) and the common GND.

I want to use the 2 pins from the TP4056 (Pin 6 STBY & 7 CHRG) to drive the dual anode LED. Right now, the charge board has 2 separate LEDs. When the system is charging, pin 7 (CHRG) is pulled to GND. A RED LED connected from VCC to Pin 7 through a resistor is turned on.

When charging is done, STBY is pulled low, CHRG goes High-Impedance and a Blue LED turns on (connected from VCC to Pin 6 through a Resistor).

How would I use my dual Anode LED with common GND since both status pins go low to GND?

[MosherIV]

How would I use my dual Anode LED with common GND since both status pins go low to GND?

I do not think you can unless :
a) you can change what Pin 6 & 7 do or
b) you need extra components to invert pins 6 & 7

[rstofer]

Google for 'common cathode pnp'
You can use PNP transistors to drive the anodes

https://www.reddit.com/r/electronics/comments/1b8mrr/pnp_transistors_for_common_cathode_rgb_leds/

The fact that the existing signal pulls to ground makes the PNP approach fairly attractive.

Or, buy the right LEDs...

[StillTrying]

My first thought was that it can't be done without more components, my second thought is the 'maybe' below.

If the outputs are open collector you don't need the 1n914s, unfortunately its no-battery indication would now be both leds on instead of both off.

[made2hack]

Google for 'common cathode pnp'

Ahh, I was using the search phrase 'driving leds from pnp' but that one makes sense.