Here’s a RasPi Volumio player that’s hidden inside a stack of books. I’m building a pair of Troels Gravesen’s 3WC bookshelf speakers and needed a player and amp to run them. I already had the RasPi assembled with a sound card and class-D amp, but hadn’t worked out what to house the player in. The RasPi is a V3 with the 7 inch touch screen, an Allo Piano 2.1 DAC and an Allo Volt amp.
I’d seen some stuff around on how to hollow out a book to make a safe hiding place for things like jewellery, or money, or if you’re an American, a gun! Decided to give a book a try to see how it works as an electronics case - after all, it would be completely natural to have a stack of books on shelf of a bookcase. A stealth amp. The stack of boards was quite deep with the Pi, DAC and amp adding up to about 75 mm height. That meant it wouldn’t fit in a single book unless it was massive, so I went for a stack of a few hardcover books.
Bought the books at a charity shop for a few dollars, then covered the front book cover with saran wrap to keep it clean and painted the page edges with slightly diluted PVA glue. Just the ordinary white woodworking glue. Left to dry for a couple of days the books started to feel pretty solid.
I tried to glue the books together at this same time, but that failed completely. There’s some coating on the loose covers that the glue won’t stick to. I separated the books at this point and cleaned the glue away from the covers.
First cut was to rebate the display in. I traced the 7" display onto the flyleaf of the first book and drilled the corners with a spade bit of the nearest diameter. This got untidy. Paper is odd stuff to work with woodworking tools. The paper either goes to dust and blows away harmlessly, or it rips and tears. Next was to use a sharp blade to cut down about 10 mm to bring the front of the display down to the surface of the flyleaf. When the rebate was completed I cut out the centre of the book where the Pi was to go and coated all the internal page edges with more slightly diluted glue.
The centres of the other books were removed using a jigsaw. Much easier than messing around with a blade. To connect the books I used some dowels. These allowed me to put a small gap between the books of about 2 mm. It’s not noticeable at a quick glance, but I was hoping that would let the air move through and cool the electronics.
All up there was about 10 hours of messing around with books and knives and glue before I could shoehorn the Pi into place. Had to open up a few parts for the plugs and cables, but nothing too difficult. Now there’s a bright and colourful screen presented when I lift the cover of the top book. Amuses the heck out of visitors to the study.
Concerned about heat in the combustible Pi case I taped a DS18B20 thermometer IC up against the back of the display. Temp varies very little between playing and quiescent and is about 30 C when the room is around 24 C. I don’t think that will cause trouble. After all doesn’t a book burn at Fahrenheit 451 according to Ray Bradbury?