[SGVHAK] Pi and Space Shuttle

[Braddock Gaskill]

Thanks for the excellent summary nopbin.  

I hope you don't mind if I cross-post this to the LUG list, since the
Raspberry Pi discussion started there and not everyone has signed up for
the SGVHAK list yet (http://sgvhak.org *hint*hint*, next meeting PROBABLY
Oct 18th) -b

On Thu, 4 Oct 2012 17:58:24 -0700, "nopbin at gmail.com" <nopbin at gmail.com>
wrote:
>> Did anyone go to the Pi demo at nullspace?
> 
> Yes.
> 
> Rob talked a little bit about the motivation behind the Raspberry Pi
> project.  Rob is currently a grad student who is taking a hiatus this
> term to tour and promote the Pi.  The Raspberry Pi Foundation has
> achieved its success with no full-time or paid employees, though Rob
> may become its first.
> 
> The RPI was created by a some Broadcom engineers who work with this
> platform in their day jobs and who hope to spur a new generation to
> become creators rather than just consumers.  The low cost is hoped to
> allow for risk taking and exploration without undo concern about
> breakage.  The Raspberry Pi platform is basically a cell phone less
> keyboard, display and cellular modem.  The hackerspace mentality of
> doing stuff because its cool is seen as the best way to inspire kids
> to engage.  They are quite happy to see that the low cost platform is
> seeding various commercial ventures.
> 
> The group had anticipated having shipped 10k units by this point in
> time, whereas in fact they have shipped a half million units.  The
> unexpectedly large demand meant they exhausted their chip supply and
> had to deal with a 23 week lead time for new chips from TSMC.  They
> now feel that they have a better handle on sustainable demand and do
> not anticipate additional supply delays.  Production is being handled
> by a UK company that approached the foundation and was able to be cost
> competitive with production in China.
> 
> There is currently plenty of RPI stock in the US.  While only rev2
> boards are currently in production, there is intentionally no way to
> specify whether you will get a rev1 or rev2 board when you order.
> Margins are so low they cannot discount the old product and cannot
> afford to be stuck with rev1 boards so they will continue to ship
> whichever board is on-hand.  (Aside:
> http://en.wikipedia.org/wiki/Osborne_effect)  Distributors typical
> sell the RPI at a $5 markup.  Distributors include Farnell, Allied
> Electronics, Newark, Element14.  Not discussed, but the distributors
> seem to be regionally focused.  Note that stock is not evenly
> maintained across distributors.  Some distributors have stock while
> others are out of stock.
> 
> Adafruit (https://www.adafruit.com/category/105) has an extensive line
> of peripherals including GPS, temperature sensors, screens, etc.  All
> (?) designs are available as opensource hardware.
> 
> The camera peripheral (5 megapixel) is going through final approval
> (?) and is expected to be available by the end of the year for $25.
> 
> Currently available, the GertBoard is a RPI add-on offering motor
> drivers, DAC, ADC, and additional I/O.  It is sold as a kit requiring
> assembly (soldering) from Newark for $47.36.
>
(http://www.newark.com/element14/gertbom/gertboard-bare-pcb-w-components/dp/24W8739)
> (Rob reported its cost at $40.)  I think (?) Rob said that
> self-assembly is required because FCC part B approval is still
> pending.
> 
> GertBoard features: (as summarized at
> http://www.raspberrypi.org/phpBB3/viewtopic.php?f=42&t=15021)
> - 12 I/O ports buffered through 74HC244 Each with an LED
> - 3 Push buttons.
> - MCP3002 : 2 channel 10 bit A/D converter
> - MCP4802 : 2 channel 8 bit D/A converter
> - ULN2803A : 6 open collector channels up to 50V ~80ma/channel
> - ATmega328P : High Performance, Low Power Atmel®AVR® 8-Bit
> Microcontroller (Arduino)
> - L6203 : 48V 4A motor controller.
> - 780xx 3V3 LDO
> 
> Between the Composite Video, HDMI and the digital interface, a wide
> range of displays are supported including TTL, Nokia DSI displays,
> laptop displays, kindle, cheap displays and old TV's that have
> Composite Video .  [Do reading before purchasing a display, because
> not all devices appear to be currently software supported yet.  GPU
> information (needed for customizing DSI and CSI interfaces) is not
> publicly available.]  Adafruit may offer a number of known-working
> displays.
> 
> Audio over HDMI is supported.  Two-way HDMI communication (enabling
> remote control) is also supported, but beware of cheap HDMI cables
> that may not connect the reverse channel.
> 
> There are a number of OS distributions available (Raspian, Debian,
> Arch, QT5...).  The reason for forking Debian to create Raspian is to
> provide hardware accelerated floating point on ARMv6, a combination
> not prebuilt by Debian.
> 
> Yes, the board runs hot, but that is the nature of the product.  No
> additional active or passive cooling is required unless aggressively
> (?) overclocking.  On-board temperature sensor is available for
> monitoring.
> 
> The GPU instruction set and architecture is not publicly available.
> (Note GPU is embedded on the same Broadcom device as the ARM.) Some
> GPU capabilities are exposed via a binary blob in Linux.  However, X11
> support is not currently provided though it will be as soon as the
> foundation developers have time.  A number of GPU accelerated examples
> are available running outside of X11.  (See /opt/vc/src in the Raspian
> distro for some examples.)  [The exact boundaries of what is and is
> not supported is remains muddy to me despite having cursorily read
> some of the online discussion.]
> 
> There were a few other odds and ends, but hopefully this gives the
flavor.
> 
> -