Hi Charles,
Good to hear from you. By the way, that heartbeat thing you mentioned
in the other thread was cool. You used arduino. I've seen some
technical articles about cross connecting an arduino with a pi.
I looked at the opencv website briefly. I also did a google search for
raspberry pi specifically on that site. There is a lot of interest in
putting it on a pi.
I found this link among many others:
http://answers.opencv.org/question/28611/how-to-get-latest-opencv-on-raspberry-pi/
The compiled binaries take 357 MB, so it would probably depend on the
number of modules running at one time and the memory management as to
whether it would exceed the Pi's capabilities. It would also be
interesting to know if the 700 MHz single core processor is a severe
limitation. It's an interesting idea.
Thanks for reminding me about AHRS. I may post my original message
there as they might be interested. I think the Pi would make a cool
robotics controller. It has good potential with lots of storage for
extensive programs for terrain maps, etc., in case it's autonomous.
I've seen articles about people attaching machine guns to autonomous
robots. THAT makes me nervous.
I've always thought that the idea of a computer with controller
capabilities would be good for anything beyond a trivial robot ... as
opposed to a controller with computer capabilities.
Unfortunately, the Pi's GPIO ports don't have anything (that I know of)
in the way of analog I/O. But, I guess you can add that with external
chips.
I rarely ever get to the DC404 or AHRS physical meetings because they're
both about an hour away from me.
Sincerely,
Ron
On 7/22/2014 11:51 AM, Charles Shapiro wrote:
Interesting. At the AHRS meeting Saturday last there was some
discussion of putting opencv ( http://opencv.org ) on a rasberry
pi. This could be a wonderful platform for your unstoppable robot army.
-- CHS
On Tue, Jul 22, 2014 at 5:13 AM, Ron Frazier (TECHC)
<[email protected]
<mailto:[email protected]>> wrote:
Hi all,
(Also posting toDC-404 )
I know many of you are Raspberry Pi fans. I just got my first one
running, and I wanted to share some of the experience. Someone in
another thread mentioned Micro Center. And that's where I bought
the unit, with some accessories coming from Frys.
My prior experience with Ubuntu helped a lot, since Raspbian,
based on Debian Wheezy, is very similar. Without that prior
knowledge, I would have found it a good bit more difficult to get
acclimated.
Just a few days ago, on July 14, a new and improved model was
announced, the Model B+. While it has the same 700 MHz processor
and 512 MB of RAM, it has a number of other newly enhanced
features. After reading about it, which happened to be very good
timing, I decided to finally jump in and get one to do experiments
with, and I decided that I wanted the new one.
The new unit has: 40 GPIO pins instead of 26, a more secure micro
SD slot instead of a full SD slot, 4 mounting holes instead of 2,
4 USB ports instead of 2, lower intrinsic power consumption (not
including peripherals), better audio, and a neater form factor.
Looking at the photos, it looks like they lost the composite video
function, but they've embedded that into the audio connector to
save space on the board.
Here's their blog post:
http://www.raspberrypi.org/introducing-raspberry-pi-model-b-plus/
The 1st 26 GPIO pins are the same electrically as the Model B rev
2. So, many things designed for the old one will work with the
new one. However, the layout of everything on the board has
changed, so things which depend on the physical configuration,
like add on boards which mate closely with the PI board, may not
work. Old cases will not work. Some GPIO breakout tools will not
work.
The same software that ran on the Model B rev 2 will work.
However, you need to update your OS Kernel. In my case, I just
downloaded the latest NOOBS software from the foundation and
installed it. I chose to put Raspbian and RISC on the memory card.
I had to fight with the thing a while to get my Belkin F5D7050
v3xxx usb wifi adapter working, but I finally got it going.
Then, I got a chance to play with it for a while. I had never
used LXDE before. But, it's not too bad. Kind of like the Gnome
2 which I got used to, and liked, on Ubuntu.
The Pi is not primarily intended to be a desktop pc. But,
surprisingly with 512 MB of RAM, it actually does pretty good at
that. I spent a while working with the Midori web browser with
scripting turned off. According to the task manager, only about
80 MB of RAM was in use not counting the cache. That leaves a
good bit for other applications to run. I've installed the
synaptic package manager and then the GO programming language. It
comes with Python and Scratch. And, I think Ruby was already
installed.
When browsing text only websites or sites with a moderate number
of images, the performance is fairly snappy. For sites with many
images, or very large images, the cpu can peg at 100% and the
system can destabilize. But, again, it's not a $ 1000 gaming
machine. But, for lightweight desktop usage, I'm really
impressed. Of course, what I bought it for is to make use of
those cool GPIO pins to actually control some experiments. This
is way better than an fpga because you can custom program it.
Also, it's really handy to have access to conventional networking
tools and a conventional file system while configuring your
experiment. That's why I chose this instead of PIC, Propeller,
Picaxe, Basic Stamp, and even Arduino.
It's billed as a $ 35 computer, but you really have to add to that
to make it work. Counting the Pi, memory card, power supply (5V,
2A), USB power cable, hdmi cable, and two PI related bookazines;
I'm into the project about $ 120. I'm providing a keyboard,
mouse, and wifi adapter that I already had. If I had to buy all
that, it would probably add about $ 50 to the project. One
website I read mentioned that you can get a keyboard with built in
touchpad to save using up one USB port. Of course, you can add a
powered USB hub if the 4 ports provided are not enough. The power
supply that runs the unit cannot provide much power to peripherals.
Later, I'll probably end up buying a circuit breadboard,
breadboarding jumper wires, a 4.3" monitor so I don't have to
always have the big one attached, a power supply for said monitor,
a video cable, a PI case, a USB cable with a power switch,
possibly an external power supply, some sensors, some drivers /
buffers, and some project specific parts like coils and motors and
magnets.
I spent many hours on Amazon looking at hundreds of products
related to the Pi. When I have some time, and after some sleep, I
hope to sort through those and post the best ones. The Model B+
is so new, most of the accessory manufacturers haven't adapted to
the new board yet. I'm sure they'll catch up pretty quickly though.
I'm really excited to see what this mini computer can do.
Sincerely,
Ron
--
(PS - If you email me and don't get a quick response, you might want to
call on the phone. I get about 300 emails per day from alternate energy
mailing lists and such. I don't always see new email messages very quickly.)
Ron Frazier
770-205-9422 (O) Leave a message.
linuxdude AT techstarship.com
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