The Hidden GoPro Security Camera was inspired by Sherlock's hidden camera in the CBS show Elementary. Above, Sherlock is seen extracting video soon after his home was breached by an intruder. What if an intruder breaks into your home and steals all of your belongings? Better hope they don't steal your calculus book too!

Step 1: Materials + Tools

Materials:

GoPro Hero 3 or later. Hero 3 or later is required because of the loop setting
64GB+ micro SD card
Book. Want a thick enough book such that the GoPro will fit easily
USB mini-b cable for GoPro. Maybe even use a USB extender
USB wall charger. Want 5V, 1A wall charger. Below 1A and your GoPro will drain faster than it will charge

Tools:

box cutter
electric drill
7/8" drill bit
wood cutting knives (optional)

Step 2: Prep Book

Turn to the middle of the book. Use the GoPro for reference and measure where to cut. You want to leave enough space on all sides of the hole so that the pages don't fall apart. You also want the hole large enough to easily fit the GoPro so leave plenty of space around the GoPro. Begin cutting. This can take a while but be patient. After you have a significant hole in the middle, start cutting from the beginning of the book or the end. Occasionally check that your GoPro fits. No? Keep cutting. Now that your GoPro fits and you can close the book, mark where to drill. Begin drilling from the inside. Once you've penetrated the cover, finish drilling from the outside.

Step 3: Prep GoPro

Follow the steps below to set your to loop video. This will generate 15min video clips and overwrite previous clips once the memory card fills up. My 64GB micro SD car holds 17 15min video clips for a total of 4:15 hours of video. This is with the video set to 1080p, 30 fps.

Turn on (Mode)
Go to Settings (Mode x4, Shutter)
Go to Capture Settings (Mode x5, Shutter)
Go to Loop (Mode x3, Shutter)
Select MAX (Mode x5, Hold Shutter)

Once the GoPro is setup, hit the Shutter to begin recording and connect the cable. Depending on your cable and hole, you may need to cut a groove in the book.

Step 4: Enjoy

Place the GoPro with cable in the book. Connect the cable to the wall charger and place the book in a bookshelf among other books. You do have other books, right? It would look pretty silly without other books.