Just got my NSCOPE. It is a kickstarter project that has delivered a simple but very nice hardware/software oscilloscope you can put on to a bread board.
If you can get your hands on one buy it. As a kickstarter participant it was ~$100.
I also have the much more expensive bitscope. But for 90% of all arduino/raspberry etc projects this works just fine and it has everything you need, pulse / sin/triangle generator , 4 input channels.
and it fits directly onto a bread board.
I seldomly get excited about hardware but this is just great.
Karl
check out [url]nscope.org[/url]
attached a screen shot testing a PIR device analog response to movements and the output trigger