expoweb/handbook/computer.html

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<title>CUCC Expedition Handbook: Expo computer</title>
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<h2 id="tophead">CUCC Expedition Handbook</h2>
<h1>Expo computing setup</h1>
<div align=center>
<p>If the internet is not working, the <b>first thing to check</b> is that<br>the black WiFi antenna is
still upright and has not been knocked sideways.
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<br>
<p>In 2018 we now have proper internet access in the tatty hut so the set-up on expo is exactly the same
as the rest of the year. An <em>Expo laptop</em> is also provided, but you should be
able to use your own computer in exactly the same way (if you brought one) as you do at home.</p>
<p>We have our own WiFi ("potatohut" and usual cavey:beery password) which is connected (deviously)
to the Gasthof campsite WiFi. So please don't stream video or do a lot of operating system updates using it
as the Gasthof is probably paying per GB to their supplier.
<h3>Two WiFi systems</h3>
<p>Our own Wifi only works very close to the tatty hut. If you are camped over the road near the
Gasthof you will need to use the Gasthof WiFi 'staudnwirt'. This takes you to a login page on a web browser and it will log you out if you stop using it or whenever it
thinks you have been on too long. Get instructions from the Gasthof campsite reception.
<h3>Expo laptop</h3>
<p>The <em>Expo laptop</em> 'debian' in the tatty hut is a Dell Latitude E4200 laptop (loaned by Phil
Sargent) which is connected to the router by a cable and not by WiFi
(it's wifi doesn't work - although that can probably be fixed). It
also has an external keyboard as a couple of vital keys are dead
(e.g. down-arrow). It runs Linux and has installed all the software
for talking to the server for:
<ul>
<li>Typing in survey data
<li>Uploading survey data
<li>Uploading photos and GPS tracks
<li>Controlling the music system
<li>Reading this Handbook
</ul>
<p>Any laptop or phone can connect to the server via the "potatohut" WiFi and,
with some configuration, can be set up to do all those things too. New expoers
are advised to use the <em>Expo laptop</em> first to see how it all works.</p>
<p>Either the <em>Expo laptop</em> or your own laptop will use the version control system to
synchronise cave data. It's easier to use the <em>Expo laptop</em> as the software is already set up.
But if you set up your own computer then you will get a more familiar environment. See
the <a href="update.htm">Expo Online Systems Manual</a> for info on how to do that.</p>
<P>Through the miracle of the distributed version control system, everyone can edit the
data on multiple laptops at the same time and it should all get merged.</p>
<p>At the end of expo we don't need to bring the <em>Expo laptop</em> back back to the UK
(though we will, as we will want to do operating system updates during the year and maybe fix that keyboard) as all the caving data updates are continuously
synchronised with the public server expo.survex.com during the expo.</p>
<h3>Printing and Scanning</h3>
We have A4 printer and scanner attached via usb cables and a usb hub (and coffee warmer) to the <em>Expo laptop</em>.
In 2018 we also connected the printer to the router with an ethernet cable and this made things more reliable.
Configuring the scanner to be used via WiFi is yet to be done, but the printer is "shared" by the
<em>Expo laptop</em> and so canbe usedby any laptop. (The printer has WiFi itself and so should be useable
directly but we haven't got this configured properly yet.) Use a usb stick to transfer files for printing
if you can't get your own laptop or phone to work with the printer.
<h3>Networking Hardware - experts only</h3>
<p>The networking hardware is an Acer Aspire netbook which keeps us logged in to the Gasthof and does firewalling, plus a WNDR4000 router/AP
to provide local connectivity and local WiFi. The antenna which we use to connect to the Staudnwirt WiFi
is a ~32cm long black stick mounted on a small shelf high
above the sink/stove area and connected via a usb cable to the Acer netbook.</p>
<p>The potato hut WiFi is running DHCP and allocating IP addresses of the form 192.168.200.x where x is 2, 3, 4, 5 etc.
<p>The <em>Expo laptop</em> has fixed local address <a href="http://192.168.200.100/">192.168.200.100</a>.
It has a 2TB drive plugged into it by USB which holds the expo music collection and a local copy of /expofiles/
<p>The router/WiFi device is on <a href="http://192.168.200.1/">192.168.200.1</a> as one might expect.
<p>The Gasthof WiFi - which you can still use - is "staudnwirt" and has no WiFi password. It allocates IP addresses in the range
192.168.2.x etc. The antenna is now on the first-floor balcony within
sight of the tatty hut window.
<p>The Acer Aspire netbook ("tclaspire3") is on 192.168.200.200 on WiFi.
This is the address to use for configuring it using ssh. So to manage the
connection to the Gasthof WiFi you would use
<pre>
ssh expo@192.168.200.200
</pre>
to run Mark Shinwell's script
<pre>/root/fakenet/runfakenet
</pre>
This typically needs to be run once or twice a day when the internt stops working.
Sometimes you have to walk over to the blue laptop and run this script directly by typing on its keyboard
as the network has collapsed so badly that <span style="font-family:monospace">ssh</span> doesn't work.
<h3>Historical Note</h3>
<p>Prior to 2018 we used to run an unconnected local network with our own DNS domain
name "potato.hut", our own server holding all the website and survey data, and published WiFi as SSID "tattyhut".
Updates to the rest of the world were done by taking an up-to-date laptop which had been in
the tatty hut to a real internet connection and
pushing the changes to the distributed version control system on
<span style="font-family:monospace">expo.survex.com</span> to be merged.
</p>
<p>In 2017 the hard-drive on our server died which triggered the general reconfiguration
to connect the tattyhut to the internet continuously and not to have our own local server. This coincides with
a much-improved WiFi service at the Gasthof in recent years.
<h3>Footnote</h3>
No, the usb coffee warmer doesn't work. It gets very slightly warm if you press
the button to turn it on but the power drain makes horrid things happen to
the laptops when they boot up. Don't touch it.
<hr>
<ul id="links">
<li><a href="index.htm">Expedition Handbook</a>
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