piCentr is an Open Source enclosure designed specifically for people who wish to build a media center PC using the Raspberry Pi2. The layout of the enclosure is meant to keep all cabling tidy and inside out of view, with accessible ports for everything you need, including front a front USB port, and rear HDMI and ethernet ports. A 3D printed internal chassis is part of the design, which holds the Pi 2 and up to two 2.5” HDDs, and is specially suited to use with the Western Digital pidrive. Remote control of the appliance is supported by installing a FLIRC USB device and the remote of your choice. The design also sports a power-wake button and a cooling fan.
Before you Start
The design files for the laser cut and 3d printed parts of the piCentr design are available on GitHub. You'll need to get those and get the parts cut / 3D printed first unless you are buying them in a kit. Note to the laser cutters - the four sides of the enclosure should be cut from 3mm material, but the top and bottom are cut from 6mm material.
You can run any OS that you would like on your piCentr. I recommend you install OpenELEC on your raspberry pi micro SD card before you start (you can still insert and remove the micro SD card through a slot in the bottom of the piCentr later if you want to make any changes). OpenELEC is an embedded operating system built specifically to run Kodi (formerly known as XBMC), the open source entertainment media hub.
Also, be sure to program your FLIRC using the pairing GUI they provide for the remote control that you plan to use, because you can't easily remove the device from the piCentr enclosure once it's assembled.
Step 1: Parts List (What You'll Need to Build Your PiCentr)
1. Raspberry Pi 2
2.a Western Digital pidrive kit (HDD and cable adapter) or
2.b Sabrant USB 2.0 to SATA/IDE Hard Drive converter with power supply and the 2.5” HDD of your choice.
3. FLIRC USB remote control device
4. A remote control that you have programmed to work with your FLIRC.
The Cables (each about 12" long)
1. 1x HDMI to panel mount HDMI cable with mounting screws
2. 1x USB type A to panel mount USB cable with mounting screws
3. 1x USB type A to female USB cable (extender)
4. 1x Ethernet to panel mount ethernet cable with mounting screws
1. piCentr laser-cut enclosure (6 pieces)
2. 40mm x 40mm x 10mm 5V DC fan
3. Panel mount momentary switch (e.g. C&K 8125 with J81 snap-in frame)
4. piCubed internal chassis (3D printed)
5.a pidrive power cable panel mount adapter (3D printed) or
5.b Sabrant power cable panel mount adapter (3D printed)
1. 17x M3x14mm screws
2. 17x M3 hex nuts
3. 4x M3x8mm screws
4. 4x M2.5x12mm screws (M2 screws will also work)
5. 4x M2.5 hex nuts
6. 2x mini zip ties (4”)
Step 2: Prepare Your Cables
Normally, you'll want to power down your piCentr through the software interface on your TV (using your remote) rather than simply unplugging it. To turn it on, you'll install a momentary pushbutton switch on the front of the device, which connects to the GPIO connector of the Raspberry Pi to wake the processor back up. The power on switch should be wired to approximately 20cm of wire and terminated in two single-pin female connectors or the outer two slots of a standard 3-pin berg connector as shown.
To keep the Raspberry Pi 2 and hard drive(s) cool, you can install a 40mm square fan on the back of the enclosure (make sure it is a 5V fan, not the more common 12V). The fan will need to be wired to approximately 20cm of wire and terminated in a single two-pin berg female connector.
Step 3: Attach the Panel Mount Connectors to the Front and Rear Sides of the Enclosure
Slide the wires for the power-wake switch through from the outer side of the front plate and press the switch into position. Use the screws that came with your panel-mount USB extension cable to mount that to the second slot from the bottom left side of the same piece.
For the rear panel, connect the HDMI and Ethernet cable extensions.
Note that if your panel mount cables didn't come with screws, they are most likely either 4-40 thread or 3mm.
Step 4: Connect Fan and Power-wake Switch Wires to the Raspberry Pi's GPIO Header
Connect the fan to pins 4 and 6 (5V and Ground, respectively) of the GPIO header, and the momentary switch to pins 5 and 9 as shown. Note that there is no connection to pin 7 of the GPIO header - the purpose of the switch is to momentarily ground pin 5, which is what will wake up the Raspberry Pi.
Next, using four M2.5 screws and nuts, mount the raspberry pi to the internal chassis. The edge of the pi with the connectors should go toward the top of the fixture.
Using four M3x8mm screws (or, alternatively, whatever screws came with your HDD), mount the 2.5” hard drive to the internal chassis, above the raspberry pi.
Now, mount the fixture itself to the bottom plate of the enclosure, using three M3x14mm screws inserted from the bottom side. Make sure you have the bottom plate the right-side up as shown - the two little slots should be to the right of the 3D printed fixture when viewed from the HDD side.
Step 5: Assemble the Enclosure Sides
Attach the USB extender cable. Use a zip tie through the provided slots in the bottom of the enclosure to secure the cable so that the female connector points toward the front of the enclosure as shown.
Insert the FLIRC module into the USB extender. For best reception, the FLIRC should be oriented with the logo side down.
Set the front and back panels on the table next to the bottom panel so that you can connect the internal cables to the Raspberry Pi.
Attach the fan to the rear panel using four M3x14mm screws and nuts.
Snap the pidrive's power connector into the second 3D printed piece. If you are using the Sabrant IDE to USB hard drive adapter, then use the other 3D printed panel mount adapter to mount the 4-pin molex power connector. In either case, then thread two M3x14mm screws through the holes on the outside of the rear panel and secure the power connector mount.
Step 6: Attach the Top and Side Panels
Flip the front and back panels up into place. The FLIRC should extend through the hole in the front side a small amount, so that it has a good view to pick up signals from your remote control.
Place the top panel in place, so that the tabs are secured through the notches in the front and back plates of the enclosure. This part is a little tricky, so you may need a friend to provide a third hand. Lay the four-sided assembly over onto one of the side pieces as shown, being careful to keep all the tabs in their respective slots. Place the last side piece on top to form the complete box.
Once all tabs are fitted into place, secure the sides using 8 M3 screws and hex nuts. Using a magnetic-tipped screwdriver, you can slide each nut into the T-slot built into the top and bottom pieces of the enclosure, then thread the screw through the side and into the nut. Be careful not to over tighten the screws or the acrylic will crack! Just tighten enough to be snug.
Once the enclosure is built, you can access the micro SD card installed in your Pi through the small slot located on the bottom side.
That's it - you should now be ready to sit back and enjoy your awesome piCentr media box!