I would like to add, for clarity, that my initial confusion was around elevated privileges. I was accessing GPIO via C++ and standard out was reporting that the pin I was setting was 0, irrespective of what I set it to. I had omitted "sudo" and while my C++ program ran happily, writing to GPIO under...

In my defence I was super tired. Still though, wow.

Thanks rpdom!

So this is driving me insane. I have an LED on GPIO 21. root@RP0:/sys/class/gpio/gpio21# echo "out" > direction root@RP0:/sys/class/gpio/gpio21# echo "1" > value LED lights up. However; root@RP0:/sys/class/gpio/gpio21# echo "out" > /sys/class/gpio21/direction -bash: /sys/class/gpio21/direction: No s...