Thanks for your suggestion. I just tried it on a freshly installed Jessie System and get the exact same error:
pi@raspberrypi:~/Pimoroni/unicornhat $ sudo python ./simple.py
Traceback (most recent call last):
File "./simple.py", line 3, in
import unicornhat as UH
File "/usr/local/lib/python2.7/dist-packages/unicornhat.py", line 14, in
ws2812.begin()
File "/usr/local/lib/python2.7/dist-packages/neopixel.py", line 114, in begin
raise RuntimeError('ws2811_init failed with code {0}'.format(resp))
RuntimeError: ws2811_init failed with code -1
Exiting cleanly
The steps I took beforehand were:
a) installation of Raspbian Jessie
b) Update with
\curl -sS get.pimoroni.com/uptodate | bash
c) Installation of Unicorn Hat with
curl -sS get.pimoroni.com/unicornhat | bash
What else can I do? Maybe the Unicorn Hat is broken?