[Discuss] Boston Linux Meeting - Building an ARM Laptop with Raspberry Pi

[tmetro+blu at gmail.com (Tom Metro)]

> Summary
> Federico discusses turning a Raspberry Pi into a laptop

If the topic of Raspberry Pis interests you, join us over on the BLU
hardware hacking list, where we discuss this and other embedded systems:

http://blu.wikispaces.com/Hardware+Hacking


Here's a summary based on my notes sent to the #BLU IRC room.

The Raspberry Pi has been an extraordinarily popular product. Last
summer they were shipping 4000 daily, and even more now. Only since
about September have stock levels been good enough that you can order
one without wait.

Two versions of the Raspberry Pi are available. Model B has been
available for a while. Model A, just released, has 1/2 the RAM (256 MB
vs. 512 MB) and no Ethernet. It also has only 1 USB port. And uses
significantly less power.

Raspberry Pis have a 32 GB maximum SD card capacity.

Federico demonstrated several of the available cases. Most are clear or
opaque plastic boxes. One had a VESA mounting plate so you could mount
your Pi to the back of a monitor.

Federico shows several daughter boards:
-a prototype board by adafruit, similar to an Arduino shield;
-Slice of Pi prototyping board; same as above, but smaller and cheaper;
(prototyping boards are basically just PCBs with a grid of holes)
-a solderless breadboard breakout adapter that attaches to Pi via ribbon
cable.

Federico then demonstrated his "first draft" of a portable workstation
based on the Pi:
-it uses a clear plastic enclosure;
-mini USB keyboard and mouse;
-and a 7" LCD monitor (TV) with RCA composite input.

Parts costs are about $125 (assuming $50 for the monitor). It's a
flexible setup, where it is easy to swap out any component. No unusual
cabling required. But all the parts are loose, so not a very slick solution.

His second draft design used:
-a black plastic case to match the other components;
-a Motorola Atrix 3 phone dock, purchased on eBay for $35, repurposed as
a keyboard, touchpad, and screen for the Pi.

A slick solution, and the dock even has a battery built in to power
itself and the Pi, but Federico noted difficulty in sourcing the HDMI
and USB cables with the right gender to mate between the dock and the
Pi. He ended up placing multiple orders on eBay to get the needed cables
and adapters, and the shipping costs add up.

Federico said the end result is a usable computer (yes, you can run a
web browser), but it still under performs other ARM systems. (An
audience member pointed out his $250 Samsung Chromebook.)

Federico said the value in the Pi is that the low cost makes them
disposable, open up new applications that wouldn't be economical for the
alternatives that cost 3 or 4 times more.

 -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/