Unicorn Hat has failing pixels


Hi, I first tried my Unicorn Hat on a new Pi Zero W but got the ws2811_init failed with code -1
Exiting cleanly error that other people have reported.

I have now put it on a Pi 3 and it works almost fine, apart from a few pixels. On one LED the red has never worked. A couple of others have failing red or blue sometimes.

I have done the apt-get upgrade, update etc and turned sound off in config.txt, but no joy. It’s powered by the ‘official’ adapter.

Is it just a bad unit, or could there be another explanation?

Many thanks,


could well be, yes, if you get failures consistently on the same pixels then there’s not much in software that could explain that.

Contact support@pimoroni.com and they’ll sort you out a replacement.


Many thanks for that - I’ve contacted support.
Best wishes,


This was fixed a few days ago, there are instructions in the bannered topic but if you’ve dismissed it already, you can grab the latest library with:

sudo pip install rpi_ws281x --upgrade


Thanks gadgetoid - I’ll give it a try.

Best wishes,


Hi Phil,

I’ve tried that on my Pi Zero W and it works fine, thank you. I still
have dead pixels on the Unicorn Hat, but support are sending me a new one!

Thanks and best wishes,