The basic idea is simple. Put a Raspberry Pi inside an aluminum case, wire it up to a screen, keyboard, mouse & batteries. Then plug in a USB hub, connect Wifi, Bluetooth, and the receiver for a wireless keyboard. We will also need to extend the Network port, add a headphone socket & speakers, fit in a battery pack, and then wire it all together! Simples.
The LapPi made joint second in the Raspberry Pi Challenge! Congratulations to the other winners, and well done to everyone who entered.
Step 1: Materials & Preparations
Before I began work I checked that the Raspberry Pi worked with the screen. I also configured the display's resolution, and made a funky desktop picture.
1 x Raspberry Pi.
1 x 8gb SD Card.
1 x Raspy Juice Expansion Board.
1 x LCD with Logic Board & Menu Board.
1 x Aluminum Case.
1 x 4-Port USB Hub (powered).
1 x +5v 1a LDO from Flytron*
1 x USB GPS Dongle.
1 x USB WiFi.
1 x USB Bluetooth Dongle.
1 x Mini USB 2.4ghz Wireless Keyboard & Track-pad.
2 x Mini Speakers.
1 x Microphone Socket.
1 x Ten AA Battery Holder.
10 x NiMh 1.2v AA Cells | or | 8 x Alkaline 1.5v AA Cells.
1 x Panel Mount USB Socket.
1 x Panel Mount RJ45 Socket.
1 x Panel Mount 2.1mm DC Socket.
1 x Double Pole Double Throw (DPDT) Slide Switch.
1 x HDMI Cable.
1 x IDE Cable.
1 x Network Cable.
2 x Metal Mesh.
1 x Passive Heat-sink.
3 x Sticky Foam Strips.
1 x Ringed Tie-Wrap.
1 x Standard Tie-Wrap.
1 x Tie-Wrap Sticky Block.
I have removed the casings from the USB dongles, the USB HUB, and de-soldered the USB dongle plugs.
The battery pack will provide 12v if used with 10 1.2v NiMh Rechargeable batteries. To get 12v from standard alkaline batteries you will need only 8 cells, as Alkaline non-Rechargeable cells provide a higher output of 1.5v. The LapPi is designed to operate on 12v.
It is worth noting that not all USB devices are compatible with the Raspberry Pi. The elinux.org wiki contains a list of verified compatible peripherals.
UPDATE: In Step 14 I replace the underpowered LDO with a 15w DC-DC Converter & fit a 2x1watt Stereo Amplifier.
Additional parts used for the update;
1 x DC-DC 15w 12v-5v 3A Converter.
1 x RK Education Stereo Amplifier.
1 x Switch (DPDT).