That's exactly what I figure. Including the WiFi dongle in one USB port, which works fine now.
I'm able to connect the RPi to the iMac via X11 over an ethernet patch cable. This works well, equipping an embedded RPi with graphic screen, keyboard and mouse for diagnostics, instantly unpluggable for free running. Result: one USB port free for experiments. All I need now is to work out how to set the onboard GPIO pins from J without too nasty a software kludge. (Python has a special library to do this). I've been making heavy use of the SD card (SanDisk SDHC), moving it a lot between RPi and Mac, so far without a glitch. But I'm planning nothing mission-critical. On Wed, Jun 19, 2013 at 1:08 AM, Eric Iverson <[email protected]>wrote: > The powered hub is nice and opens up all kinds of possibilities. SD > Cards are expensive and (relative to USB sticks) unreliable. A bad > card will work fine in a camera, but make you miserable in an RPi. > Without real world experience, my guess is the SD Card requirement and > usage should be kept to a miniumum. Your robot doesn't need a keyboard > or mouse so you have 2 free usb ports. One for a USB with J and all > your cool code. The other would be a wifi USB so you talk real time > with your robot. > > On Tue, Jun 18, 2013 at 7:47 PM, Ian Clark <[email protected]> wrote: > > Good advice! I mean to experiment with all these storage methods. > > > > The RPi model B has two onboard USB ports, but they're both in use for a > > keyboard and a mouse. The official user guide recommends use of a powered > > hub, which will make it easy to try out USBsticks and my spare USB hard > > drive. > > > > Having installed both Dyalog APL and J801, I've nearly filled up a 4GB SD > > card (the recommended entry-level). I'm about to buy a 16GB SD card, but > > only because I want the elbow room to experiment with embedded systems. A > > J-powered robot is a priority. I shall write up my investigations on the > > wiki. > > > > > > On Tue, Jun 18, 2013 at 3:56 PM, Eric Iverson <[email protected] > >wrote: > > > >> You refer to the size of the RPi SD card and I wanted to point out > >> that RPi is a real linux system and you can easily mount USB cards or > >> even terabyte external hard drives. In general programming cases it > >> probably makes sense to install J (as well as ~temp ~user etc) on a > >> USB stick and reservce the SD card for the essential service of boot > >> and OS. For embedded stuff (like a robot controller) it makes sense to > >> put it all on the SD card. > >> > >> > >> > >> On Mon, Jun 17, 2013 at 8:40 PM, Ian Clark <[email protected]> > wrote: > >> > I was hoping for that, but didn't like to ask. > >> > > >> > debian-handbook.pdf says there are numerous front-ends to apt, and > >> mentions > >> > synaptic and aptitude. But I see somewhere that these are not > recommended > >> > for the RPi, a somewhat low-powered platform. Haven't tried them, so I > >> > can't verify that. > >> > > >> > There are several operating systems for the RPi but the leader for > now is > >> > Raspbian (aka debian wheezy linux), a debian derivative (as I believe > is > >> > ubuntu). It's stunning what can be run on the RPi, but so far the > fancier > >> > UIs are more in the nature of demos, and IMO not a sound basis for > >> serious > >> > work. (But educational users will say: isn't everything a "demo"?) > >> > > >> > AFAICT the answer to "does Raspian have such-and-such"? is: if it's > meant > >> > to run under debian, then: yes, probably -- provided you've got a big > >> > enough SD card, and don't mind a long pause. But I guess for a long > time > >> to > >> > come the real way to put the RPi to serious work will be via the Linux > >> > command line. So newbies will expect to download and install J like > this: > >> > > >> > $ sudo apt-get install j801 > >> > > >> > In general I'd say, the more like the way Python does it, the better > for > >> > its uptake. (Until J gets its own following and can innovate > confidently > >> in > >> > the RPi world.) > >> > > >> > > >> > On Mon, Jun 17, 2013 at 11:11 AM, bill lam <[email protected]> > wrote: > >> > > >> >> It is hoped that J801 can enter Raspberry Pi's official > >> >> software distribution so that users can use apt to install. > >> >> > >> >> In ubuntu there is a gui frontend for apt but I forgot its name, > >> >> are there anything similar to that in raspi? > >> >> > >> >> Пн, 17 июн 2013, Ian Clark писал(а): > >> >> > Sure, any way of getting the J tarball onto the RPi's SD card is > ok. I > >> >> just > >> >> > opted for direct copying because my internet connection was flaky > >> (it's > >> >> > fine now). > >> >> > > >> >> > The "conventional" way of downloading a new app is to use "apt-get" > >> in a > >> >> > console session, which accesses the Pi Foundation's server. This > does > >> >> > require your product to be sniffed-over by the Foundation. J's > tarball > >> >> > sidesteps all that. I see however that www.dyalog.com are > delivering > >> >> Dyalog > >> >> > APL for the RPi by hacking into "apt", a method that might be > adapted > >> to > >> >> J. > >> >> > The only advantage I can see (apart from doing things the done way) > >> is to > >> >> > allow apt-get to uninstall the app as well as install it. > >> >> > > >> >> > > >> >> > On Mon, Jun 17, 2013 at 12:26 AM, bill lam <[email protected]> > >> wrote: > >> >> > > >> >> > > I guess you can also download directly from raspi using its > >> >> > > midori (untested). > >> >> > > > >> >> > > Вс, 16 июн 2013, Ian Clark писал(а): > >> >> > > > Björn Helgason wrote: > >> >> > > > > j for rapberry is available at the i801 download > >> >> > > > > >> >> > > > However did I miss it? ... > >> >> > > > > >> >> > > > Ah, I see Bill's only just announced it. ...And it all works > for > >> me, > >> >> > > first > >> >> > > > time! > >> >> > > > And very nice it looks too (Well done, Team!) > >> >> > > > > >> >> > > > Out of hubris, I straightaway ran the Lab: "Displaying boxed > nouns > >> >> > > > containing Unicode" > >> >> > > > ---to my astonishment and pleasure, it worked as it should. > >> >> > > > > >> >> > > > ---- > >> >> > > > Just for the record, here are my steps to install j801 on my > RPi: > >> >> > > > > >> >> > > > From: http://www.jsoftware.com/download/j801/ > >> >> > > > downloaded: j801a_raspi32.tar.gz -onto my iMac desktop. > >> >> > > > copied it to the /boot directory of RPi's SD card (which is > all > >> >> you > >> >> > > see > >> >> > > > of it using Finder) > >> >> > > > (but it seems it doesn't matter where this tarball resides) > >> >> > > > > >> >> > > > Then, in LXSession of RPi ... > >> >> > > > > >> >> > > > $ sudo tar -xzf /boot/j801a_raspi32.tar.gz > >> >> > > > > >> >> > > > ...creates a directory: ~/j801 (equiv to: /home/pi/j801) > >> >> > > > > >> >> > > > $ j801/bin/jconsole > >> >> > > > > >> >> > > > ...runs a j session. Once started ... > >> >> > > > > >> >> > > > install 'all' > >> >> > > > > >> >> > > > ...installs everything required (including, I guess, the > binaries > >> for > >> >> > > jqt) > >> >> > > > > >> >> > > > For convenience, I created an executable file: j and copied it > to > >> >> /bin > >> >> > > ... > >> >> > > > > >> >> > > > $ echo -e '#! /bin/bash\n~/j801/bin/jqt' > j > >> >> > > > $ chmod +x j > >> >> > > > $ sudo cp j /bin/j > >> >> > > > > >> >> > > > Now I can run jqt by simply entering: j > >> >> > > > > >> >> > > > IanClark > >> >> > > > > >> >> > > > > >> >> > > > On Sun, Jun 16, 2013 at 8:21 AM, Björn Helgason < > [email protected] > >> > > >> >> > > wrote: > >> >> > > > > >> >> > > > > j for rapberry is available at the i801 download > >> >> > > > > > >> >> > > > > dyalog apl is also available > >> >> > > > > > >> >> > > > > -- > >> >> > > > > -- > >> >> > > > > You received this message because you are subscribed to the > >> Google > >> >> > > Groups > >> >> > > > > "J Programming" group. > >> >> > > > > To post to this group, send email to > >> >> [email protected] > >> >> > > > > To unsubscribe from this group, send email to > >> >> > > > > [email protected] > >> >> > > > > For more options, visit this group at > >> >> > > > > http://groups.google.com/group/J-Programming > >> >> > > > > > >> >> > > > > > >> >> > > > > www.jsoftware.com > >> >> > > > > --- > >> >> > > > > You received this message because you are subscribed to the > >> Google > >> >> > > Groups > >> >> > > > > "J Programming" group. > >> >> > > > > To unsubscribe from this group and stop receiving emails from > >> it, > >> >> send > >> >> > > an > >> >> > > > > email to [email protected]. > >> >> > > > > For more options, visit > >> https://groups.google.com/groups/opt_out. > >> >> > > > > > >> >> > > > > > >> >> > > > > > >> >> > > > > >> >> > ---------------------------------------------------------------------- > >> >> > > > For information about J forums see > >> >> http://www.jsoftware.com/forums.htm > >> >> > > > >> >> > > -- > >> >> > > regards, > >> >> > > ==================================================== > >> >> > > GPG key 1024D/4434BAB3 2008-08-24 > >> >> > > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 > >> >> > > > >> ---------------------------------------------------------------------- > >> >> > > For information about J forums see > >> http://www.jsoftware.com/forums.htm > >> >> > > ---------------------------------------------------------------------- > >> >> > For information about J forums see > >> http://www.jsoftware.com/forums.htm > >> >> > >> >> -- > >> >> regards, > >> >> ==================================================== > >> >> GPG key 1024D/4434BAB3 2008-08-24 > >> >> gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 > >> >> > ---------------------------------------------------------------------- > >> >> For information about J forums see > http://www.jsoftware.com/forums.htm > >> >> > >> > ---------------------------------------------------------------------- > >> > For information about J forums see > http://www.jsoftware.com/forums.htm > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > >> > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
