Figured it was 'bout time I did something with the Raspberry Pi Gen 1 model B that I bought a couple of years ago. I decided to make a multimedia hub with it, and mostly re-purposed parts form other scrapped or unused devices. Thus the ScrapPi was born.
Step 1: What Features Do I Want?
A good first step is to consider what you want to be able to do with your media hub. Then prioritize the features most important to you based on practicality, and what's within your means to accomplish.
Here's what I wanted:
- An optical drive to play CD's & DVD's.
- Wireless internet connectivity for web-browsing & streaming content.
- Expandability - space, power, & connectivity to add things like a 2.5" HDD, USB TV tuner etc.
Step 2: What Do I Need?
- In addition to the RasPi, I had to figure out what parts I needed to have the features I wanted. I needed an enclosure with enough space for the primary hardware, and room for add-ons.
- I also needed a power supply with enough headroom to not only support the primary hardware, but enough extra to support add-ons. I chose to use an old DVD player for the enclosure and power supply.
- I harvested an optical drive from an old laptop.
- To interface it with the RasPi I needed an adapter to connect to USB. I already had an IDE to USB converter, but I had to buy a JAE to IDE adapter for the particular drive I used.
- I already had a generic WiFi dongle.
- The final piece of hardware I used is a 4 port USB Hub, which I also already had.
- I also chose to use a wireless keyboard & mouse that I had as the control interface.
Tip: Check the list of RPi Verified Hardware & Peripherals before selecting components.
Step 3: Stripping Down to Barebones
Time for Tools:
- Screwdrivers (standard sizes & precision).
- Wire Cutters
Preparing the Housing:
- I removed the top from the DVD player.
- I took out all of the internal parts, except for the power supply board.
Removing Unneeded Casing:
- I used small screwdrivers to pop open the plastic casing of the IDE to USB converter, & USB Hub.
- Then I removed the PC boards.
Step 4: Hardware Placement
Because I used an old DVD player enclosure, I first placed my optical drive to utilize the existing tray slot at the front. I chose to place my RasPi board at the back and utilize some of the existing connector holes for the RCA composite video jack, and the 3.5mm audio jack. Once I had the "anchor" components in place, I placed the USB Hub at the back. Then I did a dry fit including wiring to check for clearance and connection alignment.
Step 5: How Do I Mount Everything?
I was able to modify and reuse two metal brackets from the housing to mount the optical drive. I had to drill small holes in the brackets for the screws that attach the JAE adapter board to the drive. I chose to make standoffs out of wood dowel for the RasPi and USB Hub boards. I bought a 10" M to F HDMI extension cable to relocate the HDMI port to the back panel.
Time for Tools:
- Small Vice or a Clamp
- Drill & Bits
- Tape Measure
- Small File
- Utility Knife
- I carefully held each component in place and measured to determine the length each standoff needed to be. I clamped the dowel rod in a small vise and cut the standoffs with a hacksaw.
- I drilled small pilot holes in each end to accept the small screws, which were salvaged from various electronic devices.
- I attached the standoffs to the boards, held the board in place, and marked where to drill holes through the bottom of the enclosure to fasten the standoffs.
- Similarly, with the metal brackets attached to the optical drive, I placed it and marked where to drill holes through the enclosure bottom to attach the brackets.
- I had to make cutouts in the back panel for the USB ports, and the HDMI extension cable port.
- I modified the female end of the HDMI extension cable by shaving down the molded plastic so that it can pass through the panel cutout. I left tabs at the end of the molded plastic to catch the panel cutout. The panel cutout needed to be 17mm X 12mm for the cable that I used. I hot glued the cable end on the inside of the panel.
- The back panel is removable. With it in place, I marked where the cutouts needed to be. Then removed it and made the cutouts by drilling a series of holes along the cut line to pass the saw blade through. Then I made the cuts with the hacksaw. I smoothed the cuts out with a small file.
Step 6: Wiring for Power
The power supply board in my DVD player conveniently has the 3.3V, 5V, and 12V outputs printed on the board next to the ribbon cable. In most cases only the 5V output will be used. My supply has two 5V rails. I hacked an old camera cable to get a micro USB connector to power the RasPi. I had some cables with the right size barrel plugs to connect to the IDE to USB converter, and USB Hub.
Time for Tools:
- Wire Cutters & Strippers
- Soldering Iron & Solder
- Heat Shrink Tubing or Tape
- I spliced the cables with connectors to the appropriate wires for 5V from the power supply ribbon cable by soldering them together. Make sure the polarity is correct before soldering. For USB cables the red wire is + 5V and the black wire is - or ground. The other two wires are for data and wont be used.
- The joints should be insulated with heat shrink tubing, or tape.
Tip: I found that the 2.4 Amp output of the power supply wasn't quite enough when the optical drive spins up to high RPM's. I recommend a supply with a minimum of 3 Amps capacity. I bodged in the power supply for the IDE to USB converter to resolve this for now.
Step 7: Software Selection & Installation
For those unaware, there are several operating system options for RasPi. The officially supported OS is called Raspbian. A popular open source free media center software that is compatible with RasPi is called Kodi. I chose a Raspbian + Kodi install.
- I followed these instructions to write the Raspbian image file to my SD card.
- I followed these instructions to setup a wireless internet connection.
- I followed these instructions to download & install Kodi.
- I purchased an MPEG-2 license key (DVD) & VC-1 license key (bluray) from the Raspberry Pi store. These codecs are required for playing copyrighted media on a RasPi based system. Shortly after purchasing, I was notified by email that the keys were ready. Instructions were provided detailing the simple process of manually adding the keys to the appropriate RasPi text file.
Step 8: Testing & Future Additions
Testing exposed a bug that apparently is common. When the command to exit Kodi is executed, the display goes black and the RasPi stops responding. Some people have had success writing custom scripts to fix this, but I am leery about trying those. I learned that the RasPi boards have an option to connect a CPU reset switch. I found this helpful article detailing how to add a reset switch. I'm using one of the existing front panel buttons as my reset switch. Resetting this way should only be done when the RasPi is unresponsive, as there is a possibility it could cause file corruption.
- IR remote control capability using the existing IR receiver and transmitter.
- Front panel USB port.
- Relocate RasPi indicator LED's to the front panel.
- Use the two remaining front panel buttons for "hot key" functions.
Step 9: Final Steps
Once I was satisfied with the performance, I reinstalled the top of the enclosure. I modified the original disc tray face to fit the optical drive, allowing use of the eject button, and activity LED to be visible. I hot glued these parts in place. I decided to personalize the enclosure with a little paint and a decal.
Tip: Spray paint didn't bond to the plastic, I should have roughed up the surface with some sand paper first.