Fadecandy Leds stay on, don't change

[A]

I took on an led project with multible Pis each controlling four fadecandies.

Somehow one fadecandy started to have this problem:

Most of the time the connected led-strips react to the first command correctly, for example displaying red. And then they stay on this color and I can not override it with a new command.

Even when I use the debug tool in the browser with port 7890, where I push "All pixels of", the strips stay in the old color.

The fcserver.log file does only contain the four serial numbers of the four connected fadecandies. (I don't know if that should be like that)

Although I couldn't find any fix on the internet, I am asking here:

Is there a known hardware problem that can lead to my descriped problem?

I already replaced the Pi aswell the LED Strips and the fadecandy, but nothing helped.

My next clue is that one of the power cables could be causing problems.

It is not easy for me to check the hardware often, because the hardware is actually in another city than my workplace.

-> So I'd like to hear multible ideas if possible, before I can arrange to go checking the hardware.

Because I am new to this project, I don't really know which information are actually relevant to write here. So please ask me about what you have to know to help me with my problem. I'll give my best to find out these information.

I apolagize for my english, so feel free to ask me to explain something in other words.

[Michael M]

After you reboot the Pi go directly to the web browser to push the all pixels at 50% then full then off.

What happens?

Also, in the software turn client.set_interpolation = False when testing.

or when you want to change the color do the command twice.  I got tricked by interpolation thinking it does not work when it actually was working.

Example:

client.put_pixels(pixels)

client.put_pixels(pixels)

Where pixels is the variable for the string

The commands above are what I use in python

but I found that in the fadecandy examples/html  the random-color-pixel is a good test, just change the NUM-LEDS to the number of LEDs for your configuration.

and last if the voltage to the LEDs drops due to them being on, it may cause your problem.  You may have full voltage when all is off but the current from the ON LEDs creates a voltage drop and they stop responding. Voltage meter them right at the LED connector. 

For +5V they should not drop below +4.80 on a 50 LED string at full test brightness. (not an official specification, just my experience)

Hope this helps!

MikeM

[A]

Thank you for your reply!

1) The strange thing is, even after restarting everything and using thje web browser tool, the led keeps the same (has the old color on). All other fadycandies work normal.

-> I read that fadecandies had one led on the board itself, that indicates activity. I'll have to check that.

2) I'll have to find out how to do that and answer after my next test. Until now I never saw any python script of the project, I was just working in javascript on  a server , that sends commands to the pis. I asume it's not possible to change that setting from there.

-> But I am allready drawing two times / doing each command twice.

3) Trying one of the examples is something I can try!

4) Your idea with the voltage could be causing my problem, I'll test that too!

best regards

A.

[A]

Update:

All LEDs/Fadecandy-controllers might end up staying at one color. It seems randomly, which device will be the next, that behaves "wrong".

I haven't got access to the actual hardware unfortunately since opening this discussion, so I wasn't able look more into the hardware. (I still have ssh access to everything)

My best bet is that voltage problems are the cause of my problem, I'll need to check this at my next opportunity.

best regards

A.