Green Building Forum - RaspberryPi

RaspberryPi

SteamyTea — Sat, 18 Jan 2014 21:35:38 +0000

Get is set up with the normal distribution of Wheezy and get it networked to your PC and try out PuTTY and TightVNC for starters as you will be networking to it a lot.

RaspberryPi

garee — Mon, 20 Jan 2014 22:32:26 +0000

Ed - thanks for responding to my battery suggestion. Maybe I'll stick to writing software :-)

Mikeee - If you're recording your Dylos data to a PC, I've finally managed to come up with a GNUplot config file that will produce a graph from a Dylos csv file. See http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=9926&page=1#Item_20

G.

RaspberryPi

Mackers — Wed, 22 Jan 2014 14:00:45 +0000

Ok, got it set up after some messing with my wireless keyboard that caused me difficulty. Going to get it set up with PuTTY over the weekend.

Whats the difference in PuTTY and TightVNC?

RaspberryPi

Sprocket — Wed, 22 Jan 2014 14:29:39 +0000

PuTTY is primarily for Telnet (a plain text terminal protocol) over SSL (encryption through a network socket). So it is a text terminal thing. It works great for a remote command-line environment and does not usually need any extra setting up on the Pi side at all.

PuTTY also can support doing the same thing for an X-client. ie. it can transport the raw command stream a graphics terminal. You still need to add an X-terminal client though. In practice this is not usually as convenient or useful as it sounds and a lot more bother to set up.

VNC is like Remote Desktop. Your device typically runs it's normal desktop, appearing on a monitor, and VNC allows you to remotely view and operate that desktop. Applications that you run don't see any difference from the normal desktop manager environment.
TightVNC is very easy to install and very easy to use. And it works very well. Definitely recommended.

RaspberryPi

SteamyTea — Wed, 22 Jan 2014 14:46:42 +0000

TightVNC is a rascal to get to autostart at boot, I use Upstart for autostarting now (apt-get install upstart).
Then some mucking about.

WinSCP is useful to transfer files, you can write some code on your PC and then just drag the file onto the Linux box. It is just like the old Windows 3.1 File Mangler.

RaspberryPi

Mackers — Wed, 22 Jan 2014 21:37:42 +0000

Can't wait to get started, all this seems way beyond me but I'm sure ill be ok once I get started

RaspberryPi

cbatjesmond — Thu, 23 Jan 2014 21:34:21 +0000

Posted By: SteamyTeaWinSCP is useful to transfer files, you can write some code on your PC and then just drag the file onto the Linux box. It is just like the old Windows 3.1 File Mangler.

After using Unix+X11 graphics since the '80s, I'm now forced to use MS/Windows at work: I've (unofficially) installed MobaXterm*1 (from http://mobaxterm.mobatek.net/) on my work PC. The interface is a bit retro but it provides the functionality of PuTTY + WinSCP + X11 server + Cygwin*2 +VNC + RDP in one package, and can run from a USB drive when the "If it's not MicroSoft, it's not allowed" fasci^Wfriendly system administrators from the next row come around.

*1 It's free for personal use, but does remind you regularly that you can pay them if you want to.
*2 Unix command-line utilities for MS/Windows

RaspberryPi

SteamyTea — Thu, 23 Jan 2014 21:37:39 +0000

I like portable apps, shall have a look at that one.

I like Windows as well, just wish it could read Linux partitions, would make editing the SD card so easy.

RaspberryPi

Sprocket — Thu, 23 Jan 2014 22:09:54 +0000

> I've (unofficially) installed MobaXterm

Oh!
Wow!
That looks nice.

I can't believe I had not come across that before.
Thanks very much.

RaspberryPi

SteamyTea — Thu, 23 Jan 2014 22:50:56 +0000

It does look useful, shall have a play with it later.

Has loads of plugins, anyone know if this one will allow me to connect to my RPi from my local cafe?

Connect-Proxy: Simple relaying command to make network connection via SOCKS and https proxy

RaspberryPi

dereke — Fri, 24 Jan 2014 10:16:42 +0000

Another useful tool if you are stuck on windows is ConEmu (https://code.google.com/p/conemu-maximus5/)
It gives you tabbed terminals, bash, cmd etc.

RaspberryPi

Seret — Wed, 05 Feb 2014 13:20:48 +0000

Steamy, re your efforts to run an RPi off batteries, have you seen this?

http://www.theregister.co.uk/2014/02/05/mopi_smart_battery_power_for_raspberry_pi/

RaspberryPi

SteamyTea — Wed, 05 Feb 2014 14:31:11 +0000

I hadn't, but for my application it is not large enough unfortunately.
I just need a very large battery pack, size of a suitcase and about 1000 quid.

RaspberryPi

borpin — Wed, 05 Feb 2014 20:02:58 +0000

Posted By: SteamyTeaI hadn't, but for my application it is not large enough unfortunately.

Remind me again what you are trying to gather? Just temps? What was the distance to mains power?

RaspberryPi

SteamyTea — Wed, 05 Feb 2014 20:24:10 +0000

Posted By: borpinRemind me again what you are trying to gather? Just temps? What was the distance to mains power?

I have a wireless signal from the CT clamps, then the receiver is at the nearest 13A socket. Trouble is, it is on farms, and then tend not to have many 13A sockets within about 10m of the transmitter.

RaspberryPi

SteamyTea — Fri, 14 Feb 2014 12:14:28 +0000

Right, been playing with the RPi today and have been trying to find out how to upload files to 'the cloud'.
I was going to use my 4share account as it supports ftp. Trouble is I am struggling to find out how to set the RPi up to do this.
I keep going round in circles with wget, git, weex, cron. All seems very complicated.
Help anyone.

RaspberryPi

Ed Davies — Fri, 14 Feb 2014 13:01:56 +0000

curl(1) Curl Manual curl(1)

NAME
curl - transfer a URL

SYNOPSIS
curl [options] [URL...]

DESCRIPTION
curl is a tool to transfer data from or to a server, using one of the supported protocols (DICT, FILE, FTP,
FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP, RTSP, SCP, SFTP, SMTP, SMTPS, TELNET
and TFTP). The command is designed to work without user interaction.

curl offers a busload of useful tricks like proxy support, user authentication, FTP upload, HTTP post, SSL
connections, cookies, file transfer resume and more. As you will see below, the number of features will make
your head spin!

curl is powered by libcurl for all transfer-related features. See libcurl(3) for details.

E.g., to send a file called â€œw.jsâ€ from my laptop (â€œbillâ€ as in Bill Hewlett) to my tablet (â€œedwinâ€ as in Edwin Hudl ) which is running an FTP server on the non-standard port 3721:

edavies@bill:~/temp$ curl -T w.js ftp://edwin:3721/
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  6162    0     0  100  6162      0  42626 --:--:-- --:--:-- --:--:-- 67714
edavies@bill:~/temp$

Still, FTP is horribly old-fashioned and insecure (passwords sent un-encrypted and so on). If there's any chance to SSH then take it. rsync would be your friend then, though scp would be fine. There's also SFTP (FTP over SSH) but I've not had cause to use that and would have to research if/how curl supports it.

RaspberryPi

Ed Davies — Fri, 14 Feb 2014 13:26:41 +0000

Just had a look at 4share.

I think you can put files via https (WebDAV):

curl -T somefile --tlsuser steamy --tlspassword secret https://webdav.4shared.com/

or something like that.

RaspberryPi

SteamyTea — Fri, 14 Feb 2014 14:29:19 +0000

Curl did make my head spin. I have tried wput, like wget but the other way around.
Having trouble getting it to log into my 4share account, but that may be a different issue.

With these file transfer programs is it always the files you want to move followed by your account details and then account location.
And do I have to type in user, followed by a space before my username, some seem to want it and others not.

RaspberryPi

Seret — Fri, 14 Feb 2014 14:42:31 +0000

Curl is the way to go ST, give it a crack.

RaspberryPi

Ed Davies — Fri, 14 Feb 2014 15:32:17 +0000

Posted By: SteamyTeaWith these file transfer programs is it always the files you want to move followed by your account details and then account location.

Generally it's options, in any order including the file to be sent, then the URL at the end.

Posted By: SteamyTeaAnd do I have to type in user, followed by a space before my username, some seem to want it and others not.

Unfortunately, that tends to depend on the program.
Curl, for example, accepts:

-Tw.js
-T w.js
--upload-file w.js

but not, of course:

--upload-filew.js

Other programs with similar options might also accept:

-T=w.js
--upload-file=w.js

but curl seems not to. This is, indeed, an area of annoying inconsistency.

RaspberryPi

SteamyTea — Fri, 14 Feb 2014 16:12:56 +0000

Right, have installed curl but seem to be having trouble getting into my account. Shall play with it after I have fed the poor and needy.

RaspberryPi

Ed Davies — Fri, 14 Feb 2014 16:23:54 +0000

Just created a 4shared account and tried to upload using WebDAV as shown above. It failed because a client certificate is required, not that the message is exactly explicit about the problem:

$ curl -T dsc00205-small.jpg --tlsuser secret@edavies.me.uk --tlspassword secret https://webdav.4shared.com/
curl: (35) error:14094410:SSL routines:SSL3_READ_BYTES:sslv3 alert handshake failure

I also tried following their instructions for accessing it from Linux

https://www.4shared.com/features/access_to_4shared_with_webdav/howto.jsp#q2

and that didn't seem to work, either - just hung. Could connect to the FTP server on my tablet that way, OK.

Would try FTP to 4shared but that's a premium service - not paying for that.

RaspberryPi

SteamyTea — Fri, 14 Feb 2014 20:56:16 +0000

It used to work with FTP a few years back (I uploaded my 'Grass Growing' video using it and filezilla. Might have changed since then.

Anyone know of a free FTP web based storage?

RaspberryPi

borpin — Fri, 14 Feb 2014 21:33:34 +0000

Try dropbox (not done it myself) http://www.dropboxwiki.com/tips-and-tricks/using-the-official-dropbox-command-line-interface-cli

RaspberryPi

Ed Davies — Fri, 14 Feb 2014 23:20:38 +0000

How about just emailing the data back to yourself?

There are various Linux command line utilities to do that sort of thing but they all seem to want to take over the world rather than just send a single message.

Probably simplest to do it in Python if you're running some of that anyway. Just sent myself a message via my web provider's SMTP server (which is secured using TLS) from the Python command prompt - only half a dozen or so lines. Will write it up properly tomorrow if you're interested.

RaspberryPi

SteamyTea — Sat, 15 Feb 2014 07:09:21 +0000

I am interested in how to do it from Python as I have a script running anyway.

RaspberryPi

Ed Davies — Sat, 15 Feb 2014 11:12:31 +0000

Main reference:

http://docs.python.org/2/library/email-examples.html

Very useful to do:

import smtplib
help(smtplib)

then scroll down to read about SMTP_SSL.

Following sends me an email with numbers 0 to 9 on separate lines:

#!/usr/bin/python3

import smtplib
from email.mime.text import MIMEText
from datetime import datetime

data = [i for i in range(10)]

frm = 'cowshed@edavies.me.uk'
to = 'ed@edavies.me.uk'

msg = MIMEText('\n'.join(str(x) for x in data))
msg['Subject'] = 'Methane production to %s' % datetime.utcnow().isoformat()
msg['To'] = to
msg['From'] = frm

s = smtplib.SMTP_SSL('domain name of smtp server')
s.login('user name on smtp server', 'password on smtp server')
print(s.send_message(msg, from_addr=frm, to_addrs=to))
s.quit()

Numbers just show that what MIMEText wants is a single string with new line characters between the lines.

You could just email yourself the data every time it grows to 50 kilobytes or so. I'd suggest doing it whenever there's more than the set amount of data and you haven't tried in the last few minutes. If the email seems to have worked then clear the data and start it building up again. If not, leave the data and try again in a few minutes.

Wrap the whole send process in a try/catch block. Also check the response to send_message for errors. Needs some investigation what send_message returns if things haven't worked.

RaspberryPi

Ed Davies — Sat, 15 Feb 2014 11:29:45 +0000

Changing the obvious lines to:

to = ['ed@edavies.me.uk', 'steamytea@xxx.com']

msg['To'] = ','.join(to)

sends to multiple recipients, it seems. The send_message(to_addrs) parameter naturally takes a list. I hope Steamy got a copy at his actual mail server which is not entirely the same as 'xxx'.

RaspberryPi

SteamyTea — Sat, 15 Feb 2014 11:50:02 +0000

Yes I have, wondered what it was.

Seems I have screwed my image that I was using trying to set it up to run Google Drive. Email seems an easier method.

So shall be trying it on a spare RPi.
Thanks