Update, 2019-06-12:

I revised the design of the wall mount. Six new configurations are available. The first change is that it now uses either the larger and more reasonably-sized #6 or #8 American flat heat screws (metric M3 or M4) instead of the very tiny and hard to install #4 that was previously used. I've had to relocate mine several times and getting those tiny screws in and out sucks. The second change is that now there is only one screw that fastens the mount to the surface. There is no real need for the second one, and once you have attached the body of the thing to the mount you can't access the second mounting screw anyway.

The Pi Microcam is a compact all-in-one webcam. It includes a camera, PC, and web server (running on the PC). At its core is the Raspberry Pi Zero W and its associated "spy cam". All it needs is a wireless network and a micro USB power supply.

This is the most compact Pi Zero W-based design released to the public domain at the date of this posting, to the best of my knowledge. Existing designs typically utilize the older, full-size Raspberry Pi camera, which is much larger and has a much longer ribbon cable than the "spy cam."

The back piece has two versions, one with the hinge on the short side opposite the SD card, and one on the long side opposite the USB/HDMI ports. The wall mount has three versions with different arm lengths. The photos show the case with the hinge on the short side, and the shortest wall mount.

Design highlights:

• Case dimensions of 84 x 34 x 12 mm (not including mounting brackets)
• Access to SD card, USB ports, and HDMI port without opening case
• Integrated strain relief clip on wall mount helps prevent accidental disconnection and damage to the USB port
• Two mounting options provided, with easy angular adjustment both vertically and horizontally

Items needed:

• Raspberry Pi Zero W - Must be the "W" version for onboard wifi
• Pi Zero W Spycam - https://www.adafruit.com/product/3508
• Micro SD card of at least 8 GB
• (6) M2.5x10 mm socket-head cap screws and hex nuts. (12 mm fasteners can also be used, but the knuckle is designed to accept only a 10 mm screw unless you modify it with a drill.)
• (2) #4 wood screws, at least 1" long - OR - (2) M3 wood screws, at least 25 mm long.
• Drill bit between 2.5 and 3.0 mm diameter, to drill out the four counterbored holes at the corners of the front and back pieces.
• Micro USB power connection -- I wish I could tell you how many watts or amps it needs, but all I can tell you is that it needs a good solid connection. If you can't get the Pi to boot AND stream images, try a better cable.
• Wireless internet (wifi)

NOTE: This design is NOT waterproof and should not be mounted outdoors unless it is well-protected -- under the eaves of a roof, for example. I may design a follow-up version at some point that is water-resistant. Heat build-up inside a fully-sealed case is a concern, which is why this design includes a vent grille on the back.

NOTE 2: This post will be followed up with instructions on how to actually install the required software on your Pi to run the webcam. In the meantime, do some googling; it has been done a million times.