[ale] My Raspberry π is here

[Ron Frazier (ALE)]

"Michael H. Warfield" <mhw at WittsEnd.com> wrote:

>On Wed, 2012-10-17 at 13:50 -0400, Ron Frazier (ALE) wrote:
>> Hi Mike W,
>> 
>> Your message made me think of a specific application for the pi that
>I
>> have need of.  I have to maintain my Dad's Windows Vista computer. 
>He
>> lives in Jasper.  I can drive up there to do things and do so
>> periodically.  That also give us the opportunity to have lunch, etc.
>> However, it's nice to be able to do things by remote control.  I can
>> already do this with a Windows application called CrossLoop, kind of
>> like Go To My PC, etc.  That works OK if Windows is working and all
>> the communications stuff is working.  However, I cannot reboot that
>> way and I cannot manipulate the BIOS.  Dad has to help me get logged
>> into the machine.
>
>> I need a fully encrypted remote kvm.  It would sit between the pc and
>> it's monitor, mouse, keyboard, and router; and would, once I'm
>> properly and securely authenticated, transmit all kvm signals back
>and
>> forth to me.  It should also allow local pass through so the original
>> keyboard, mouse, and monitor still are usable.  That way, I could
>> reboot the machine if necessary, and even get into the BIOS.  Nice to
>> have features would be remote control of the power outlet, status
>> information for the power outlet, remote control of the power and
>> reset buttons, and a visual light signal at his location to indicate
>> when I'm connected.  He should be able to switch off the remote
>> connection at any time if desired, in case anyone nefarious breaches
>> the security.  I may even want a key switch to be turned on at his
>> site to enable login, although being able to log into the machine
>when
>> he's not even there would be helpful.  The ability to transfer files
>> back and forth would be very helpful.  I suppose I could start
>> Crossloop once I boot up, but that seems a bit kludgy.  The interface
>> between my machine and his needs to be fully graphical without any
>> cooperation from the OS on his system.
>
>> I know such things are on the market, but they are quite expensive.
>
>Yes they are.  I have some Ascend IP KVM's that are crazy expensive for
>one of my labs.
>
>I strongly suspect you may have a problem with your desire for it to be
>pass-through where it sits between the computer and the associated
>keyboard/video/mouse device allowing you to share simultaneously.  I'm
>not really sure what might be on the market available for such an
>application.  I have a Digi Passport I-KVM single port IP KVM that was
>reasonable in price, when and where I bought it, but it doesn't support
>the kind of passthrough you would be looking for.
>

I'm actually doing something similar on a local basis at my house.  I have two vga usb kvm's here.  One kvm is attached to my wife's work computer and a second machine, an old Dell laptop.  If she wants to do work, she switches to that.  If she wants to do personal things, she switches to the Dell.  The other kvm is attached to several computers that I use but it is also attached to the Dell.  If I need to switch over to it to do maintenance or use it when she's not doing so, I can do that.  Both kvm's feed keyboard and mouse inputs to the Dell via USB.  For the video, I have a physical 'Y' splitter cable attached to the vga output on the machine.  One side of the Y goes to kvm1 and the other side goes to kvm2.  Since the signals are analog, you can do that.  Either one of us can access and use the Dell with our own separate keyboard, mouse, and monitor.  It gets a bit interesting when we're both switched onto it.  Both screens dim and distort a bit, but are usable.  You could probably prevent that with some buffering.  Either one of us can move the mouse and it works.  Either one of us can type on the keyboard and it works.  We can both see the video output from the computer on our own monitors, and the laptop's local attached monitor screen is still active too.  The only problem is that the Dell sometimes gets confused when it trys to  read the monitor id to set resolution and aspect ratio.  So, I just preset those when she alone is connected and when I alone am connected, and it generally works.

>http://www.digi.com/products/consoleservers/digi-passport-i-kvm#overview
>
>They price out at at several hundred up at CDW but can be had cheaper
>if
>you shop around.  Still...  Big owwie.  I think I found one somewhere
>for under $100 but that was some time ago and I will not attest to how
>well it works.  It's not the most reliable device in my setting.
>
>Certainly, with USB, you have the potential of handling the keyboard
>and
>mouse if you can get a host-mode emulation going with the keyboard and
>mouse coming into the RP and running a keyboard mouse emulation out to
>the computer.  It's doable.  If it's doable on android (and we have it)
>it's doable.  To do it with the PS/2 interfaces - I wouldn't even
>attempt it.  Video can be challenging on one front but may even be

I'd have to check to see if his keyboard and mouse are PS2 or USB.  Even if they're PS2, you can still attach second ones to the USB ports.  Windows will be just fine with multiple input devices and I suspect that Linux would too.  The one possible snag would be whether the BIOS will recognize and respond to a USB keyboard at boot time.  So, if it says press ESC to enter the setup, you actually want that to work.  On one of my other computers, I have both a USB and PS2 keyboard attached.  Almost always, it responds to the USB keyboard fine at boot.  Sometimes it doesn't, and I have to press the reset switch to reinitialize the USB controller (along with the rest of the motherboard).  On occasion, I've had to resort to pressing keys on the PS2 keyboard to get a response before Windows kicks in.

>easier in other ways.  A USB video capture device could be used to
>passively capture the screen output.  You could use a VGA to component
>adapter, along with some sort of sharing device.  Video capture at any
>decent resolution is going to be VERY processor intensive, though.
>Anything more than NTSC or PAL resolution and you're going to need
>something beefy like the Hauppauge HD PVR or better.  There's another
>pricey toy (I have one).  That's about $170 at Fry's last I looked.
>
>> By the way, I like the idea of the power disturbance analyzer.
>> Available bandwidth may be a problem, depending on what the highest
>> harmonic you want to measure or the shortest spike.  If the sensor
>pod
>> had it's own micro controller and USB port, you could probably get
>> much higher bandwidth.  It would be interesting to tie some of the
>> sensor pods from the PC based O-Scope products to the pi and run some
>> DSP algorithms or something like matlab on the pi.  I think some of
>> those sensor devices or probe devices use USB.
>
>Well, bandwidth should not be a major problem.  Most audio capture will
>handle from about 30Hz up to maybe 20KHz two channel without breaking a
>sweat.  I don't even particularly care where the 3dB points are because
>it can always be equalized in software and I'm probably just going to
>feed it straight into an FFT anyways.  If I wanted to reach up into the
>MHz range, one of the digital O-scope pods would be nice but would be
>overkill in bandwidth and, quite frankly, weak in resolution.  The
>reasonably priced ones are only 8 bits per channel.  Admittedly, 24
>bits
>per channel is overkill from an audio capture but I would rather have
>more resolution.  It may not catch X-10 120 KHz signals or Insteon at
>131 KHz but I would have to filter them out of the data anyways.
>Voltage spikes I'm not really concerned about too much as far as
>measuring them goes, only detecting them.
>
>If I compare this to say a Dranitz Line Disturbance Analyzer (my
>existing one died may years ago and it's too expensive to replace for
>such little use) I think it has the potential to do as well or
>better...
> 
>> Sincerely,
>
>> Ron
>
>This is good though.  This is really what we need.  Brainstorming ideas
>we can put these things to work for.  I like your KVM idea...  May take
>some work but hell yes!
>

If you decide to tackle either of these projects, I'd like to be involved.  In the case of the KVM, I could learn a bunch and solve my problem at the same time.  Of course, I'd still want to have lunch with Dad on occasion.

However, I also have a strong interest in electrical power.  My wife and I bought into an energy saving franchise in 2000 where we would go into factories and office complexes and analyze their power usage and recommend improvements.  For advanced clients, we could offer power quality services.  The business failed because of three reasons primarily.  Power is cheap here, and nobody wants to spend money to save 10% on their bill with a 5 - 10 year payback.  But, also, the vendor was unreliable and we were under capitalized.  In any case, that hasn't changed the fact that I have a strong interest in the topic and have studied it a good bit, although my specific knowledge may be a bit rusty after 12 years.  I also have a BS-EET degree from back in the 80's.

Sincerely,

Ron


>Regards,
>Mike
>
>
>> "Michael H. Warfield" <mhw at wittsend.com> wrote:
>> 
>> >On Wed, 2012-10-17 at 10:11 -0400, Derek Atkins wrote:
>> >> "mike at trausch.us" <mike at trausch.us> writes:
>> >>
>> >> > On 10/16/2012 04:05 PM, Scott Castaline wrote:
>> >> >> Finally got my π today and wifey wasn't here to grill me, so
>I'm a
>> >> >> very happy camper! Happy, happy, happy! Playtime now begins.
>Even
>> >the
>> >> >> FedEx guy has already been playing with one already.
>> >> >
>> >> > They are wonderful little things.
>> >> >
>> >> > I ordered 5 after last month's meeting so that we could play
>with
>> >them,
>> >> > and I am already looking at putting them to use to solve some
>> >> > long-standing problems that these are just absolutely perfect
>for
>> >solving.
>> >
>> >> Okay, what long-standing problems are they absolutely perfect for
>> >solving?
>> >
>> >I can come up with several just off the top of my head.
>> >
>> >Easy:
>> >
>> >*) A "little black box" with ssh keys, cron, and highly restricted
>> >access do manage remote server operations and interserver
>> >communications
>> >using key auth forwarding over ssh.
>> >
>> >*) A security storage module holding CA keys or PGP keys much like a
>> >smart card might due but higher capacity, higher performance, and
>lower
>> >cost.
>> >
>> >*) A remote serial console driver to monitor servers.  Sort of an
>add
>> >on, out board, server management module.
>> >
>> >*) Server monitor.  Drop it on a remote network running nagios and
>> >health checks against your bigger servers.
>> >
>> >*) Logging server.  Have it running rsyslogd and just saving syslog
>> >events off the local network to the SD card where it can't be
>tampered
>> >with by intruders who can't reach it.
>> >
>> >Because they're cheap, you can use lots of them as embedded
>controller
>> >devices for for small specialized tasks like these.
>> >
>> >A much more difficult straw man idea I've been wrestling with:
>> >
>> >(This one I believe Mike T will relate to immediate based on some of
>> >our
>> >recent discussions...)
>> >
>> >How about a DIY power line disturbance analyzer?  Take your AC power
>> >line signal (both phases) and divide it WAY down (say 1000:1) so it
>> >fits
>> >within range of an audio signal.  If you're not really concerned too
>> >much, some nice resisters will do along with some micro-fuses and
>> >transorbs.  If you are paranoid about playing with high voltage,
>some
>> >linear opto-isolators are even better, just more complicated.  Now
>feed
>> >those two signals to the stereo input of a USB audio adapter.  It's
>> >just
>> >a 60Hz signal, after all, with the two phases 180 degrees out of
>phase.
>> >Most ADC (analog to digital converter) daughter boards I'm seeing
>for
>> >the RP are two slow for what I want (15 samples per second for a 16
>bit
>> >8 channel board is NOT going to hack it).
>> >
>> >Now you can monitor and measure things like...
>> >
>> >* Surges
>> >* Sags
>> >* Spikes
>> >* Dropouts
>> >* High frequency noise (notch for X10 and Insteon if desired)
>> >* Frequency
>> >* Voltage
>> >* THD (Third-order Harmonic Distortion)
>> >* Imbalances
>> >
>> >Basically the things that a decent line disturbance analyzer does
>only
>> >without the $10,000 price tag.  Commercial units I've worked with
>will
>> >handle more phases and more inputs at higher voltages, are hipot (hi
>> >potential) tested and isolated for workplace safety, and are often
>> >calibrated and tracible back to NIST standards, which are not
>> >necessarily things we need (hipot isolation is desirable to protect
>the
>> >device but may not be necessary as a safety feature do to more
>limited
>> >voltages in the home).  That could be in the price range where you
>> >install it near your breaker panel and just leave it there and
>download
>> >data occasionally.
>> >
>> >You can not measure things outside of the audio range of the device.
>> >Things like DC offsets and very low frequency that an ADC could
>measure
>> >but are generally not of serious concern.
>> >
>> >Add another audio input and some induction picks and you could add
>> >current monitoring.  Another audio input and you can have neutral to
>> >earth ground (common mode) monitoring.  Some nice beefy batteries
>can
>> >keep it going through some long power failures.  With enough
>on-board
>> >horsepower to do a decent FFT and you could store large amounts of
>> >signal data and events.
>> >
>> >Yes, I've read the articles indicating that audio input to the RP
>has
>> >been less that sterling (sucks?  still?) and may be rather
>> >problematical.  That's something I really want to test and compare
>to a
>> >more general purpose device.
>> >
>> >> > 	--- Mike
>> >
>> >> -derek
>> >
>> >So...  Those are just a few ideas.
>> >
>> >Anyone else?
>> >
>> >Regards,
>> >Mike
>> >
>> >> --
>> >>        Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
>> >>        Member, MIT Student Information Processing Board  (SIPB)
>> >>        URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
>> >>        warlord at MIT.EDU                        PGP key available
>> >>
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>> 
>> 
>> --
>> 
>> Sent from my Android Acer A500 tablet with bluetooth keyboard and K-9
>Mail.
>> Please excuse my potential brevity.
>> 
>> (To whom it may concern.  My email address has changed.  Replying to
>former
>> messages prior to 03/31/12 with my personal address will go to the
>wrong
>> address.  Please send all personal correspondence to the new
>address.)
>> 
>> (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
>> 
>> 


--

Sent from my Android Acer A500 tablet with bluetooth keyboard and K-9 Mail.
Please excuse my potential brevity.

(To whom it may concern.  My email address has changed.  Replying to former
messages prior to 03/31/12 with my personal address will go to the wrong
address.  Please send all personal correspondence to the new address.)

(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