Below are images of the latest in the Simple Pi Rack line (following on from Simple Pi Rack
and Simple Pi Rack Mk II
). The Simple Pi Rack 3 features a set of six Raspberry Pi 3 on top and one embedded. The embedded Pi is connected via GPIOs to a SainSmart relay switch, which is used to switch power on/off to the Pis on top. Power comes from a 50W (5V x 10A) PSU. Inputs to the embedded Pi can also by made through a menu using the AdaFruit 16 x 2 character display with Up/Down/Left/Right/Select buttons (front right) or using an I/R remote (sensor top front left), there is also a realtime clock inside. The Clock and the Display share the i2c GPIO pins. All the Pis are connected to wired ethernet via a 8 port TP-Link 5V (0.6A) 100Mbps switch. The embedded Pi is mounted to expose its ethernet and usb ports to the front and has its HDMI port extended and exposed to the left side, ensuring that the rack is usable over the network and locally as a workstation. On/off switches have also been provided at the front to physically control when the Pis have power.
Here is an image of the rack assembled and running:
and here is an image showing the internals immediately before final assembly:
and finally here is a view from the rear showing PSU air venting and power lead connection:
The bottom and top were constructed in a similar manner to the Simple Pi Rack II, but using off-cuts of twin-wall polycarbonate sheets, instead of wood, which helped greatly with embedding the HDMI connector to keep the Pis upright and USB power shim, and for keeping the wiring neat.
The case was made from the white plastic underside of a lid, shaped like a tray (the photocopier part) of an HP all-in-one printer, split into four sections (front, back and sides) to form a casing around the rack top and botton. Front/Back/Sides/Top and Botton are screwed together using small self-tapping screws into small lego blocks shaped, inserted and glued into the polycarbonate, making it solid - I'll supply more pictures soon!
I hope you like it!