Lego Raspberry PiBook
Introduction
I have built several Lego cases for computer hardware over the years, but with the Raspberry Pi it's been possible to experiment more. The Pi's small size and low temperature mean there is a lot of scope to rapidly try many case designs.
Photos
 3/4 View |
 Front |
 Outside Front |
 Outside Back |
 Audio and Composite |
 SD Card Slot |
 USB ports |
 The Screen Controller |
 Keyboard Removed |
 Outer Case Removed |
 The Core |
|
Building
Construction is based on two 16 x 24 stud Lego baseplates (12.8cm x 19.2cm). Most of the walls of the case are 1 stud wide.
For the non-Lego components, most of the effort is expended on wiring up the items and trying to fit all the connections in. It should be possible to free up more space by using/crimping shorter internal USB and Ethernet cables.
Diagram of the wiring of the PiBook
The Instructions
These instructions were created with Leocad, although there is a Linux version it is not in the default Raspbian repositories, I'll look into compiling up a version for the Pi.
These instructions are from a slightly earlier version of the case, before I added the USB hub.
The hinge between the two halves, is made of technic lift-arms, pinned into technic beams in the case walls.
The Screen
Finding a suitable screen proved difficult, my first choice was a 3.5" LCD commonly used in car reversing systems.
- Pros
- Very very cheap (£15)
- Cons
- A bit small
- Despite being advertised as 640x480 the panel itself was 320x240. This is not really a high enough resolution to read text in a terminal window.
- Composite Video only, which is nowhere near as good as the quality from VGA or HDMI
- 12V operation, not 5V
- I blew it up trying to rewire it for 5V
I shopped around for a replacement screen that had a higher spec, and found a very useful one on Ebay. The screen is a INNOLUX AT070TN92 and the controller board is a PCB-800099.
- Pros
- Much higher resolution, good enough for viewing terminal text. 800x480.
- HDMI input for lossless quality, and VGA and Composite inputs as well
- Large input voltage range, 5-24V
- Cons
- 3x More expensive (£45)
- No case, just a bare panel and board
This screen requires you to tweak the config.txt on the boot partition of your Pi OS. This is because although it is HDMI the controller board reports that it supports modes that it cannot actually display.
hdmi_cvt 800 480 60 6 0 0 0 hdmi_group=2 hdmi_mode=87 hdmi_ignore_edid=0xa5000080
Cost Breakdown
| Cost (inc delivery) |
Description | Source | |
|---|---|---|---|
| Raspberry Pi | 34.00 | Model B | From Stock CPC Farnell |
| HDMI to HDMI lead | 1.21 | 30cm | Ebay (sinedy) |
| Screen | 40.50 | INNOLUX AT070TN92 | Ebay (njytouch) |
| Keyboard/Mouse | 18.00 | USB over radio | Ebay (cablemaster) |
| USB Hub | 5.00 | 4 port, 2 on each side | From Stock |
| PSU | 5.00 | 5V 2A | From Stock |
| Battery Pack | 12.00 | 20000mAh | Ebay (kryonet_ltd) |
| Power Socket | 5.00 | 4.0mm/1.7mm socket | Ebay (jegs11) |
| Ethernet extension | 2.59 | 50cm plug to socket | Ebay (cables-and-more) |
| USB leads | 2.00 | 2 x charger leads | Poundland |
| Lego | 35.00 | Estimate of cost | From Stock |
| Power Plug | 1.89 | 4.0mm/1.7mm plug | Maplin |
| Total | £ 162.19 | Total ex stock | £ 83.19 |
Future Improvements?
A simple improvement could be to add a USB WIFI dongle, there is currently a free internal usb socket which could be used.
A more difficult improvement would be the provision of an internal battery. There really isn't any free space in the base section, but in the screen there is theoretically space for a flat battery.
Applications
The PiBook should be able to run any Pi supported OS and application, with the slight limitation of a smaller than usual screen resolution. I've successfully run Raspbian, RaspMC and RISC OS.
I use the PiBook for ARM assembler programming (using GCC inline assembler), watching videos and have setup a Nintendo Game Boy Advance emulator (using an external USB gamepad).
Public Appearances
The machine has visited a few shows, and is also a regular at the London Raspberry Pint.
- 4-6 July 2013 - Silicon Dreams/Vintage Computer Festival - Snibston, Leicestershire.
- 21 September 2013 - Cambridge Raspberry Jam.
- 26 October 2013 - RISC OS London Show, Feltham, London.