expoweb/handbook/computer.html
2022-11-23 11:41:12 +00:00

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<title>CUCC Expedition Handbook: Expo computer</title>
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<h2 id="tophead">CUCC Expedition Handbook</h2>
<style>figure {font-weight: bold; font-size: small; font-family: sans-serif;font-variant-caps: small-caps;}</style>
<h1>Expo computing setup</h1>
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<p>If the internet is not working, the <b>first thing to check</b> is that<br>the black WiFi antennae are
still upright and have not been knocked sideways.
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<br>
<p>Since 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 ("tattyhut" 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> in the tatty hut is a 2011 Dell Latitude E4200 laptop (on loan from Philip
Sargent) which is connected to the router by a cable and also by WiFi
(it's wifi configuration was fixed by Sam in 2019). It
also has an external numberpad as a couple of vital keys are dead
(e.g. down-arrow). It runs Linux (Debian) and has installed all the software
for talking to the server for:
<div class="onright">
<figure>
<a href="/piclinks/typing.htm"><img src="/images/typing.jpg"></a>
<br><figcaption>Basecamp computer in 1991 - in the old potato hut</figcaption>
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</div>
<ul>
<li>Typing in survey data
<li>Uploading survey data
<li>Uploading photos and GPS tracks
<li>Reading this Handbook
</ul>
<p>Any laptop or phone can connect to the server via the "tattyhut" 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>The laptop is usually connected to an extra LCD screen so that you can see surveys more easily as the laptop itself is small.
<p>For experienced expo surveyers the <em>Expo laptop</em> is also set up to use the version control system to
synchronise cave data. New expoers should use the web forms, which work from any browser on any laptop. You can
configure your own laptop to do bulk upload of many files and manage the version control yourself, but
initially it is easier to use the <em>Expo laptop</em> as the software is already set up (cryptographic key
exchange etc. is pre-configured). See the <a href="computing/basiclaptop.html">Basic Expo Laptop</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 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 used by 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>The Expo Laptops: Crowley's Friend: Aziraphale</h3>
<p>In 2023 we have another general-use laptop (it was also in use in 2019). This is not connected by any cabling and just uses WiFi. Like the <i>expo laptop</i> it is running Debian Linux and has the same set of software installed
(survex/aven, tunnelx, therion, git etc.) and you login to it using the username "expo" and the usual cavey:beery password. It is an R61 14-inch Thinkpad on loan from Michael Sargent and it is called "Aziraphale". The <i>expo laptop</i> is called "Crowley". Crowley has a 64GB microSD card plugged into it which holds the local copy of <var>/expofiles/</var> whereas Azirophale has a big enough solid-state drive (128GB, new for 2023) to hold <var>/expofiles/</var> (and Azirophale's SD code slot doesn't work).
<p>Both laptops have had RAM upgrades and solid-state disc upgrades.
<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
to provide local connectivity and local WiFi. The antenna which we use to connect to the Staudnwirt WiFi
is a dual antenna WiFi tiny black box on a small shelf high above the sink/stove area and connected via a usb cable to the tiny dark-blue Acer netbook 'tclaspire3'. In 2023 there will be no separate router: routing is will all be done by this Acer notebook [PENDING CORRECTION/UPDATE].</p>
<div class="onright">
<figure>
<a href="computing/potato-hut-network.jpg"><img src="computing/potato-hut-network-small.jpg"></a>
<br><figcaption>Hut Network - click to enlarge</figcaption>
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<p>The potato hut WiFi is running DHCP and allocating IP addresses of the form 192.168.1.x where x is a number between 11 and 99 .
<p>The <em>Expo laptops</em> have a dynamic local address of this form, as does any other laptop connecting to this WiFi.
<p>The Acer Aspire netbook ("tclaspire3") is on a static address <a href="http://192.168.1.100/">192.168.1.100</a>.
<p>The Gasthof WiFi - which you can still use - is "StaudnGast" and has no WiFi password but there is a login webpage. 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 is on 192.168.1.100 on WiFi.
This is the address to use for configuring it using ssh when everything else has failed. So to manage the
connection to the Gasthof WiFi you would use
<pre>
ssh expo@192.168.200.100
</pre>
to run Mark Shinwell's script (re-edited by Sam 2019)
<pre>/root/fakenet/runfakenet
</pre>
This typically needs to be run once or twice a day when the internet stops working.
Sometimes you have to walk over to the blue Acer Aspire netbook 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.
<p>The Acer netbook needs to have its persistent networking set up correctly <i>in addition to the script</i>. This is the
<b>wicd</b> gui program that has an icon in the top-right of the sceen in the system panel. (Or search in all applications in the Internet section
for the wicd application). Set the checkboxes so that the Acer does connect to any network except the Staudingast wifi network,
and also tick the 'automatica;lly reconnect' checkbox for the "StaudnGast" network.
<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.
<p>In 2018 and 2019 we had good Internet access at basecamp, but the router was returned to its owner and in 2022 Wifi reception from the gasthaus was poor. A new Wifi device (not a router, just a dual-antennae receiver) is to be used in 2023, pending configuration with the acer aspire laptop, wich we hope will improve everything to how it was in 2019.
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Go on to: <a href="computing/onlinesystems.html">Expo online systems</a><br />
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