Can't get Bi-colour LED to be both colours at once.

Hi guys,

I know the LEDs CAN be both colours at once since with a previous circuit they were working fine.

I had to buy an LED controller chip however since the previous circuit wasn't enough for what we needed. I have this chip Adafruit 24-Channel 12-bit PWM LED Driver - SPI Interface [TLC5947] : ID 1429 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits and these LEDs 3mm Bicolor Diffused LED - Blue & Amber LC LED-N300TBY2D

Now I have figured out how to get it to power an output with the setPWM command (I'm a bit of a programming noob), however .. I cannot get the LEDs to be both blue + yellow at once.

So I set say, outputs 11 and 12 both on at 100%, connect 11 to one input of the LED, 12 to the other, then the cathode goes to ground. Only one colour will show at a time. If I unplug the dominant colours input then the other one shows. But they won't both be on at once. (However in a previous circuit .. I could get them both on at once by doing the same thing pretty much).

My code is basically: (although I'm pretty sure its a hardware/electronic/circuit thing, not software!

setPWM(11, 4095);
setPWM(12, 4095);
write();

So I don't know if its something to do with the chip or not? I'm really new to this but I need to get it done/learn so, I'd appreciate any help/baby steps!

Cheers!

We don't comment on code snippets. Either post the entire code or don't post any. If you have a question about how to use a specific function that's different, but posting a couple of lines of code and asking us why it doesn't work is not going to get you anywhere here on the forum.
Post the entire sketch, either by using the CODE TAGS toolbutton [</>] (on the left), or by attaching the sketch using "Attachments and other options" (below).

And use real code. The statement "setPWM(11, 4095);" matches no existing predefined functionality. Shortening the name of full commands out to save typing is not coding...

setPWM(11, 4095);
setPWM(12, 4095);
write();

Where did you get this code. It doesn't look like something you just made up but it is not arduino code.
It looks like it is from some other hardware or software. You aren't trying to run non-arduino code are you ?
What experience do you have writing code for arduinos ?

C'mon people :wink: OP provided 'links' to the board that is used as well as the LEDs; at least there was an effort.

adafruit board
adafruit library; will show where setPWM() comes from :wink:
bicolor led

I agree that a full code is needed as well as a basic schematic diagram (photo of hand drawn one or a real one)

It looks like the LED's you have are common cathode and all the Adafruit tutorials use common anode so how have you got these LED's connected up to the Adafruit board?

@Havik,
Why would you buy common cathode leds for a common anode chip ?

CASE A: You didn't look at the datasheet for the leds
CASE B: You didn't read the datasheet for the chip
CASE C: You've NEVER used an LED before.

Which is it ?