After searching a lot on Google and reading answers on stackoverflow and blogs, this is by now my understanding of the relationships between UIView’s different properties:
UIView is based on CALayers, CALayer has a shadow property and can have a mask, the mask is a CGPath, CGPath comprises one or more shapes (arc, rectangle, etc.), and can perform boolean operations (union, subtraction, etc.). This is how it looks after putting above-mentioned theories together:
I want to create a drumkit that transmits MIDI signals wirelessly, to some MIDI processing device, say, a Mac or an iPhone. Arduinos are powerful and easy enough to get started with, but I want my project to be more portable and task specific, so I decide to shrink it down to an attiny84 powered board.