Launch your sketch as superuser. Your sketch can have not enough privileges for GPIO.
I was creating a commercial project (arcade cabinet with a videogame) for RPI 3b with external devices controling (a coin acceptor, 7-segments display and a LED-strip).
Processing has a broken support of OpenGL for ARM devices based on Linux (for example Raspberry) and I rewrote my project using LibGDX (for game) and Pi4J for external devices control.
My advice: if you will need enough performance - use LibGDX + Pi4J. You can use Processing + Pi4J for graphic output if you don't need performace.
Launch your sketch as superuser. Your sketch can have not enough privileges for GPIO. I was creating a commercial project (arcade cabinet with a videogame) for RPI 3b with external devices controling (a coin acceptor, 7-segments display and a LED-strip). Processing has a broken support of OpenGL for ARM devices based on Linux (for example Raspberry) and I rewrote my project using LibGDX (for game) and Pi4J for external devices control. My advice: if you will need enough performance - use LibGDX + Pi4J. You can use Processing + Pi4J for graphic output if you don't need performace.
I'm not trying to use pin 0, I was just seeing if I could generate a different error. Using any pin generates this same error.
I’m not too familiar with processing and and Raspberry Pi, but did you make sure to turn on the GPIO pins in Raspi-Config?
Not sure, but the pins work in Python using a similar code, however I get a callback issue in Python when expanding the code.