WS2811 chip readout

Hi
I Would like to read the output level of the 3 Led outputs of the WS2811 chip ( I don't need a Led attached) however it seems to be negative voltage or something, since it is designed for common anode Led. How can I read these voltages with a Arduino Nano or Pro micro or even an ATTiny ? Does it need some small conversion circuit? I connected it directly to a Arduino analog in but somehow the WS2811 chip fries rather quickly.
Thanks

The obvious question is why ?

Do you mean the current consumption?

to vary the LED intensity I suppose it changes the voltage , or is it a PWM ?

Coz I want to use the signal to drive something else.

Have you actually researched the WS2811 at all? It uses a digital interface, which is made very clear in the data sheet that you can download from numerous sites.

OK how to you drive a analog LED with a digital interface then using the WS2811 output ??

Please back up and explain your overall goal.

The WS2811 is a 3-channel PWM open-collector running at 2KHz (i think, the datasheet doesn't mention it as far as i can tell)

The WS2811 receives a signal and drives the open collectors.

That is totally fine, depending a little on what you want to drive. I drive simple RGB ledstrip using 3 mosfets and 3 pullups and 3 inverting gates.
So if you explain what it is exactly what you want to drive, we can be of more help.

You'll need to measure the PWM interval. Let's assume 500 microseconds (2 kHz).

  pinMode(InputPin, INPUT_PULLUP);

  unsigned long pulseWidth = pulseIn(InputPin, LOW, 1500ul);  
  if (pulseWidth == 0) // Timeout so pin is HIGH or LOW
    pulseWidth = (!digitalRead(InputPin)) * 500;
  dutyCycle = pulseWidth / 500.0;  // 0.0 to 1.0

If you want to read the outputs, connect them to pull up resistors, with the outputs connected to a digital input.

But it is >= 400Hz PWM, as explained in the data sheet:
https://cdn-shop.adafruit.com/datasheets/WS2811.pdf

If you need help connecting to "something else", please tell us what that is.

I want to control a servo

You know what values you have sent to the WS2811 so why not base the control of the servo in those values ?

Yes i know the values. What do you mean? It must run through the ws2811

What must run through the WS2811 ?

Just suppose that you write 255, 255, 255 to an LED it will be white. If you want the servo to move to a certain angle when the LED is white then test the R, G and B values that you sent and if they are all 255 then move the servo appropriately

Since a servo requires a signal in a completely different format, i think you will need an additional MCU of some kind doing the translation.

You could roughly filter the PWM signal using a couple of resistors (a diode won't be needed since the open-collector is a one way street already) and a capacitor, and use a small MCU like an ATtiny 13 to series of measurements, then average those and send a pulse to the servo according to the results.

I understand what can be the benefits of such a setup, but it might also be an option to control a servo from a different source.
You see like this it is a bit of a trip, you will lose part of your resolution, and to be honest, i have never done it (though i am planning to do it once just because it can be handy and fun) So there is no guarantee of success.

As I understand it, the OP wants to drive a servo directly from the 2811. That will never work. Also someone who can't figure out how to test it, probably can't figure out how to build it.

apparently you did not read the posts. and your answer really doesn't help anyone.

@heng1 I don't think that you have explained why you want to read data from the chip to control a servo, but you have obviously decided that is what you need to do

Forget about that solution for now and describe what it is that you want to achieve rather than asking about a solution that you have come up with

I have been following this thread since it started, I'm waiting for you to explain what you're doing so I could maybe help.

Also, I did answer you "bare" question from the first post, in my reply #11. Have you tried it yet?

Your answer, "to drive a servo" is only a half answer because people would want to know why. It's like:

"Why are you walking backwards?"
"To go home".