Author Topic: The big 'ole Raspberry Pi topic  (Read 27407 times)

0 Members and 1 Guest are viewing this topic.

Offline old-and-in-the-way

  • Concert Hall Hasbeen
  • ****
  • Posts: 312
  • Good Vibes 5
  • That's what I heard him say
Re: The big 'ole Raspberry Pi topic
« Reply #90 on: February 16, 2014, 12:50:18 am »
TB, you could probably use a PI for that, but bear in mind that you will need a display of some sort. Raspberry Pi uses both HDMI and RCA video out, so you could do that somehow. You could maybe code for a small LCD display, but I don't know how well that would work with what you are planning.

I haven't read beyond this point, so apologies if it's been mentioned already, but the pi does have headers for mobile phone screen modules.

HOWEVER, I wouldn't use a pi for web browsing (even if only banking) because the responsiveness would be painful -- until there's an X11 backend for the Pi's GPU, you're running X on the arm part alone, and it's likely to be very frustrating to use.

Mind you, I have a pi with 1TB RAID1 over USB, and that's even more painful than X would be, so feel free to ignore me as inconsistent and full of crazy talk.

Offline TB-AV

  • Honorable Ex-Mod
  • All Time Legend
  • *****
  • Posts: 14966
  • Good Vibes 329
Re: The big 'ole Raspberry Pi topic
« Reply #91 on: February 16, 2014, 12:57:47 am »
Ah.. ok.. I was not aware of any of that... I think there is simply just a lot I don't get about the whole concept. I should have one in hand by next week though so perhaps once I see it, things will become a bit more clear.

It's kind of odd to me they seem like they can be fairly powerful and then on the other hand apparently can't do things which I think of as simple... like browsing.
Gone

Offline old-and-in-the-way

  • Concert Hall Hasbeen
  • ****
  • Posts: 312
  • Good Vibes 5
  • That's what I heard him say
Re: The big 'ole Raspberry Pi topic
« Reply #92 on: February 16, 2014, 01:03:58 am »
You may find the browsing performance is acceptable for your needs.  If it isn't, it'ss be because X has a fairly hefty memory footprint and CPU overhead, the graphics toolkits (Gtk+, Qt and friends) are quite hefty beasts and web browsers themselves also tend to be quite resource heavy these days.  All of them together may make things a bit slow.  Everything should still work just fine (my pi with the raid often gets a load average of 10 or so, which usually means a heavily loaded system, but can still keep up -- problems only really kick in for me when the load average hits 30 (can happen when copying lots of large files from my old backup disk to the raid-over-usb), at which point things can start to get a bit upset)


edit to add: And it occurs to me that I should probably explain load average if I want that lot to make sense.  Load average is a count of the number of processes in a given state in a given period of time.  The states are "running" (ie, using actual CPU cycles) and "uninterruptible sleep" (ie, things waiting for something to be read from the filesystem).  A load average that is equal to the number of CPUs indicates that the system has very few wasted cycles (it's a very rough measure).  Actual performance depends as much on the cause of the current load average as the load average itself.

I think I just made this all very confusing.  It's 1am here and I'm clearly in no fit state to speak sense :-S

Offline TB-AV

  • Honorable Ex-Mod
  • All Time Legend
  • *****
  • Posts: 14966
  • Good Vibes 329
Re: The big 'ole Raspberry Pi topic
« Reply #93 on: February 18, 2014, 04:12:22 pm »
http://www.youtube.com/watch?v=v0pLdY2Ap5Q

This guy has overclocked to 1G but that looks pretty fast to me.... At least for paying bills and the few simple things I will need to do it should work.

Also I got to thinking.... If the OS is on an SD card, can't I also configure the SD card for banking to boot up with the stuff I need saved to the desktop and then simply have that ready when I want to pay bills and boot it... or perhaps even have a banking usb dongle.

That way the rest of the time the Pi can be used for something else.

Am I thinking about this wrong. Can't I configure an SD card and it boots. then on my desktop are say 5 shortcuts to 5 banks/bills and one document with my passwords. So I click teh links, login and do what i have to do.

Then shut down, remove SD card, put in new card and I have a whole new computer. Put banking SD in safe place... and I suppose there must be some way to make a backup image of it should it get lost or go bad?
Gone

Offline old-and-in-the-way

  • Concert Hall Hasbeen
  • ****
  • Posts: 312
  • Good Vibes 5
  • That's what I heard him say
Re: The big 'ole Raspberry Pi topic
« Reply #94 on: February 18, 2014, 05:21:22 pm »
http://www.youtube.com/watch?v=v0pLdY2Ap5Q

This guy has overclocked to 1G but that looks pretty fast to me.... At least for paying bills and the few simple things I will need to do it should work.

For relatively simple things it'll probably be fine, just don't expect it to be as fast as your desktop/laptop.

Quote
Also I got to thinking.... If the OS is on an SD card, can't I also configure the SD card for banking to boot up with the stuff I need saved to the desktop and then simply have that ready when I want to pay bills and boot it... or perhaps even have a banking usb dongle.

Yep.

Quote
That way the rest of the time the Pi can be used for something else.

That's pretty much how they intended it to be used.

Quote
Am I thinking about this wrong. Can't I configure an SD card and it boots. then on my desktop are say 5 shortcuts to 5 banks/bills and one document with my passwords. So I click teh links, login and do what i have to do.

Yep.

Quote
Then shut down, remove SD card, put in new card and I have a whole new computer. Put banking SD in safe place... and I suppose there must be some way to make a backup image of it should it get lost or go bad?

Yep.  From a linux system with an SD card reader and a hard disk, something along the lines of:

Code: [Select]
sudo mount /dev/sda1 /mnt
sudo dd if=/dev/mmcblk0p2 of=/mnt/desired/path/to/image/sdcard.img

Should work -- the image will be called sdcard.img in desired/path/to/image/ in the filesystem on the hard disk.

The commands given above will be more or less what you want on a raspberry pi with a USB HDD.

On a linux desktop or laptop with an sd card reader, try:

Code: [Select]
sudo dd if=/dev/mmcblk0p2 of=~/desired/path/to/images/sd-card.img
If your distribution or configuration does not use sudo, su to root and use the commands without sudo.


Offline TB-AV

  • Honorable Ex-Mod
  • All Time Legend
  • *****
  • Posts: 14966
  • Good Vibes 329
Re: The big 'ole Raspberry Pi topic
« Reply #95 on: February 18, 2014, 05:52:15 pm »
Fantastic.... I don't know why it just hit me that every SD card can be a whole new device. I suppose because I saw so many people using multiples but I suppose they all had specific tasks. Like the media server I do intend to have one for that but for this one it's good to know I can mess around with it. ... and even if I break it, it's not like I can't bank on my regular pc.

Thanks for the code... I'm actually starting to almost see what some of it means...

Quote
sudo mount /dev/sda1 /mnt

subuser ( I become root user? ) mount ( mount a device for use ) /dev/sda1 ( directory /dev/hard drive 1 partition 1 ) /mnt ( go to this directory )   

Quote
sudo dd if=/dev/mmcblk0p2 of=/mnt/desired/path/to/image/sdcard.img

sub user ... dd ( copy a file ) if=/dev/mmcblk0p2 ( lost me on that one... If, in the /dev directory .. there is a jar of M&Ms???     of=( still lost ) /mnt/desired/path/to/image/sdcard.img ( this writes the image to that directory tree on some other Linux drive ( not the Pi ) (or a linux drive attached to Pi).. not real clear where this drive is... seems like it must be some other Linux machine.

What exactly does that sound like in laymans terms?
Gone

Offline old-and-in-the-way

  • Concert Hall Hasbeen
  • ****
  • Posts: 312
  • Good Vibes 5
  • That's what I heard him say
Re: The big 'ole Raspberry Pi topic
« Reply #96 on: February 18, 2014, 06:30:52 pm »
Yeah, more or less

sudo is "super user do", ie "run the following command as root"

dd is "disk duplicate" (if is "input file" and of is "output file")

/dev/mmcblk0p2 is the device file for partition 2 on the 0th multimedia card block device

/dev/sda1 is the first partition on the first hard HDD (prior to kernel 2.6 you'd have had hdXY for IDE disks and sdXY for SCSI disks -- that all got harmonised several years ago)

/mnt/desired/path/to/image/sdcard.img is the mounted filesystem from an external HDD (eg, one plugged into one of the USB ports (most likely via a powered USB hub, since any HDD caddy taking its power over USB will leave too little for the pi to be able to run)

Did I miss anything?

You can mount disks on other systems in  a variety of ways (CIFS using windows file sharing on windows, or samba on linux/macosx, NFS, sshfs and probably others) but we'll consider those advanced topics for now.

Also under "advanced topics" is using netcat (possibly with ssh tunnels to hop NAT or firewalls)  to copy files arbitrarily across networks.



Edit to add:  So, in layman's terms, "duplicate the file /dev/mmcblk0p2 byte for byte and stick the result in /path/to/sdcard.img"

Offline old-and-in-the-way

  • Concert Hall Hasbeen
  • ****
  • Posts: 312
  • Good Vibes 5
  • That's what I heard him say
Re: The big 'ole Raspberry Pi topic
« Reply #97 on: February 18, 2014, 06:41:29 pm »
You may think "this dd stuff is weird.  Why not just use copy?" -- device files are special, and using copy on them will likely do the wrong thing.

In general, though, use copy (cp) not dd.

Other commands worth knowing:

  •   mv - move or rename.  This is atomic within a device, but becomes a copy followed by a remove if moving across devices.  This is because within a device, mv can just change the label, but across devices all of the blocks need moving over and if you don't do this as a copy-then-remove, you risk losing data if something breaks.
  •   rm - remove (anybody who tells you to do anything that looks like "sudo rm -rf /" or "rm -rf /" shouldn't be trusted and is trying to get you to trash your system, so don't do that!)
  • ln - link (as in, create an alias for a file; the same set of blocks then have two names, and there are two routes to get to them
  • man - check the manual (see "man man" for the manual's manual)
  • cd - same as dos/windows
  • mkdir - same as dos/windows
  • rmdir - remove an empty directory (safer alternative to "rm -r" which will recursively remove a directory and any files it happens to contain)
  • help - see the shell's help for shell builtin functions and constructs

Offline TB-AV

  • Honorable Ex-Mod
  • All Time Legend
  • *****
  • Posts: 14966
  • Good Vibes 329
Re: The big 'ole Raspberry Pi topic
« Reply #98 on: February 18, 2014, 06:46:46 pm »
Ahh.... ok... that multimedia block is over my head   and I need to find a little pocket glossary of terms...

The wiki stuff gets a little too out there...

I kinda saw the general idea but there are always  some terms in the middle that throw me. I wish that new book would be out before June... I think I'll drop by the library and pick up the most recent general reference I can find.

I was just wondering.. .that Coursa web site might have some intro Linux classes I could attend. I need to check that out.

It seems like its not so bad but I think I will need a handy reference... even if I have to write my own for whatever I'm dealing with. IOW, I might fumble my way through it once, but the next day, I'm like how the hell did I do that?
Gone

Offline old-and-in-the-way

  • Concert Hall Hasbeen
  • ****
  • Posts: 312
  • Good Vibes 5
  • That's what I heard him say
Re: The big 'ole Raspberry Pi topic
« Reply #99 on: February 18, 2014, 06:53:44 pm »
This is the reference I used (in, uhm, 1995 or so).  Surprisingly little has changed.

as for "multimedia block" -- you don't need to care about that.  Just know that /dev/mmcblkX is an SD card, and /dev/mmcblkXpY is a partition on that same SD card.

Offline TB-AV

  • Honorable Ex-Mod
  • All Time Legend
  • *****
  • Posts: 14966
  • Good Vibes 329
Re: The big 'ole Raspberry Pi topic
« Reply #100 on: February 18, 2014, 07:00:16 pm »
  •   rm - remove (anybody who tells you to do anything that looks like "sudo rm -rf /" or "rm -rf /" shouldn't be trusted and is trying to get you to trash your system, so don't do that!)
I once had a fairly new job... it was about 2 minutes to 5 on a Friday Holiday weekend... most everyone had left. I had about maybe 50-60 upper management on my floor. Netware servers. I had to install whatever anyone needed and be sure they had all the rights.

So they kept the MS Office stuff on one of the servers. Someone walks up and needs Excel right now. There was something about the local instal that needed to be deleted and then pull the new setup of the server and install that..... I got mixed up....... deleted the whole shooting match off the server.....!!!

So I call this guy that worked in my group.... he was at another office and of all things in a meeting with my boss.... AND... they put me on speaker phone..... I tried to save face a bit by asking why the delete inhibit flag wasn't on.....( "because you're not supposed to delete the files!!" ).. Damn... how embarrassing. Anyway... very big company so I just had to call the backup guys and wait around on the empty floor until I got all that done.... so yeah,,, I'm kind of familiar with that delete everything feeling...

Gone

Offline Dan Graves

  • All Time Legend
  • *******
  • Posts: 6567
  • Good Vibes 168
  • Is on the Outside, looking in
Re: The big 'ole Raspberry Pi topic
« Reply #101 on: February 19, 2014, 03:25:05 am »
On a slightly related note, i got a new router for my parents, but the antennas somehow didn't seem to be as powerfull as the ones on the old WRT54G, and WiFi reception in the kitchen was lacking, resulting in rather spotty radio play from the Pi MusicBox.
Normally i'd have re-purposed the old WRT54G with DD-WRT and made it into a repeater, but the poor thing was dying as it was, so i had to think of something else...
So i went full hacker mode and made three of these : http://www.freeantennas.com/projects/template2/index.html
Two i put on the actual antennas so they'd beam most of their signal towards the kitchen area, then i made the third rather oversized and put it behind the router so a lot of the signal normally bouncing into the wall behind it would reflect towards their desktop PC.
Result ? About 9 DB gain in signal strength in the kitchen, resulting in a strong enough signal for the Pi to continue it's life as their newfound webradio/spotify streamer, and their signal now overpowers the nextdoor neighbours' WiFi signal so much that i can barely see it anymore on my WiSpy  8)
"You need a little bit of insanity to do great things"
--Henry Rollins

Offline TB-AV

  • Honorable Ex-Mod
  • All Time Legend
  • *****
  • Posts: 14966
  • Good Vibes 329
Re: The big 'ole Raspberry Pi topic
« Reply #102 on: February 19, 2014, 05:46:15 am »
I've heard they are good.... never made one though. You know what's funny,,, I bought one of those WRT54 routers yesterday. Found a GS with the higher mem and flash. Going to try to set up a mesh node to see if anyone else is around. There is a Ham radio distro and we can legally use CH1.

The thing I don't understand is, and I would need another router to find out... but it tells you to not change the SSID... so you stay on this particular mesh made for ham radio. Then it says don;t change that unless you know what you are doing. So I am thinking can't I just get two or more routers and change the name and have a private mesh... OR... is there places in the code that references that SSID and the code will break. I'm thinking no, but who knows.

================================ On yet another Pi note.....

So tell me something... I only use a cell phone but it somehow possible to have an IP phone without buying phone services.... I'm not real clear what he's doing here... The reason I ask is because I have to pay $120 a year for an Internet fax service and no one really sends faxes any longer but I can't take a chance just yet to not have one.

I'm also still using an iPhone 3 on AT&T.... I know they sell other lines and I know my ISP sells phone lines... but am I mistaken that there is no way for me to get around this whole phone line deal or fax deal without actually buying the service.... and if you buy the service.... why not just pick up the phone and make a call?  Apparently he has a remote office he is typing into or something?

Anyway.... anyone see any potential here for me to cut some costs or enhance my current setup... I am thinking of upping to iPhone 5 because there is a couple of apps I can use to make my work a bit easier but AT&T screws you on that deal too since they won't let you tether. I'm just kinda thinking about if and how I should rework some of my setup.

Oh, I also saw these things and for under $100 you can add a Motorola dock to a Pi which gives you a nice keyboard and folding screen. You have make some cables but no big deal.






« Last Edit: February 19, 2014, 04:06:10 pm by TB-AV »
Gone

Offline Dan Graves

  • All Time Legend
  • *******
  • Posts: 6567
  • Good Vibes 168
  • Is on the Outside, looking in
Re: The big 'ole Raspberry Pi topic
« Reply #103 on: February 20, 2014, 03:41:56 am »
Ok, some questions then to clear up some things i'm wondering about TB :
1) Mesh network ?
Why would you want to lay out a mesh network ?
It's complicated work, would take a LOT of routers/AP's to set up, a lot of time, and serves no purpose outside complicated, large scale corporate settings...
Unless you have a ranch that spreads several acres and you want WiFi all over the place.
Again, you seem to be making things FAR more complicated than they need to be.
I'm not trying to take the piss by saying that, i just mean to save you some time and effort here.

2) Wait, what, you're not allowed to use channel 1 ?

I can't see any reason not to, it's in the 2.4 Ghz region, pretty sure HAM/Amateur Radio isn't using those bands.
I think there may be restrictions on channels 12 and upwards, but channel 1 ?
Not to my knowledge.

3) Not changing SSID ?
Then how the xx--xx are you supposed to tell your AP apart from all the others ?
I don't give a xx--xx what the manuals say, i've been changing my SSID's to funky names since i first started wardriving with my brother and we ran a Rogue AP off a secondary car battery.
See the picture above, and guess which AP's are run by me..

On your Pi question : i have no idea what you're asking here.

What Hackman is doing is replacing a rather large in home PBX (basically a digital switchboard) with the Pi to handle his incoming phonecalls around the whole place, run through Skype.
Basically he bought Skype's service where they provide you with a local phone number which anyone can call from any phone and also from Skype, so he can 'cheaply' make and receive calls from all across the globe.
"You need a little bit of insanity to do great things"
--Henry Rollins

Offline TB-AV

  • Honorable Ex-Mod
  • All Time Legend
  • *****
  • Posts: 14966
  • Good Vibes 329
Re: The big 'ole Raspberry Pi topic
« Reply #104 on: February 20, 2014, 04:46:13 am »
I think you mis-read my post. Licensed amateur radio -can use legally- 2390 - 2450Mhz

So that's below CH1 and up to CH8 but I think they like to use CH1 because of the free space in the low end. The channels are 22Mhz wide ....

Although yours is 44Mhz wide for some reason. Why is your bandwidth so wide?

So anyway there has been an every growing mesh based on this one distro named HSMM-MESH. I just wanted to fire one up and see what's out there near me.

But.... I was simply wondering.... if I were to change the SSID... would that software still work,,, maybe it will maybe it won't.... it was invented for the HAM radio community.

=== About the other thing.... I must have missed the Skype thing... I forget about Skype... still never tried it...

But maybe you didn't know... I got my technician and general class license for radio over a year ago and am studying for my Extra class now.... and all this mess overlaps. The only way you can really get it is to simply jump in and do it. So I thought that mesh network was pretty cool.

with that mesh network, provided there were enough nodes, if the systems went down, we would still have a mini Internet so to speak. There are a lot of people over here prepping for the possibility of unfun things happening.... and they aren't the nut jobs you see on TV.... communications is good thing to have and it something I sort of have a feel for..... so for this particular thing it's sort an exercise in learning. Where you are thinking node per floor, or three nodes in a big building the HAM mesh is thinking nodes 10+ miles apart, and mobile nodes. There are people actually creating solar powered repeaters and lets say a node as well and hiding them on mountain tops, and that increase your distances by miles. It's not like a regular wifi network..... and it's fast... a lot faster than other HAM radio data links. So for instance... Let's say I had a node in my home. then I got somewhere say 10 miles away... I could actually access my own Internet connection..... and that's why I would need my own SSID of course.... otherwise the entire mesh would have access to my Internet connection.

Also... and this gets real complicated... I still don't understand it but through software,,, radio signals can be super weak, like hidden in the noise floor, and still be recovered..

The Pi stuff is really for my enjoyment and hopefully to make my life a bit more easy/enjoyable.

..... btw... I'll see that bandwidth and raise you 8dB



ETA: .. I guess one thing I was asking about the phone stuff is... is there something I am missing or could do with this asterisk stuff to where my iPhone could be put to better use.... Like could I take calls on an IPPhone desk phone instead of having to use the iPhone itself.... IOW... am I missing anything with all this new technology or not so new... but I haven't bothered to use it.
« Last Edit: February 20, 2014, 06:22:59 am by TB-AV »
Gone

 

Get The Forum As A Mobile App