If you've got both arduino and raspberry pi, and lots of external boards you might have used or tried to use to get your arduino home system to even better functionality but got bored or distracted it's a good read. You'll use what you have, you'll play with rasp's great interfaces and you'll get back to the topic of "supah home intelligence", as the previous book owner expressed the state after having it read (while giving me this book). And as I love to tinker with some toys and had similar things done at work already it was clear to me that the book might change my work and use more of the rasp's potential. I was right, yet I was also in a comfortable situation of having my "board garbage collection" a little bit slimmer. If you own only a rasp pi you would have needed to procure a few of such external interfaces to finish the basic projects. But if you used rasp pi only as a home network file server/media streamer this migh show you how you can change it into your very own HAL9000 bastard progeny. You might also spend a few bucks in the process, but it's not equivalent to your average lady on a shopping spree shoe/bag/clothes hunt ;) So quite interesting projects, easy to follow instructions and you're off hidden in your workshop for some time.