CUCC Expedition Handbook

Expo computing setup

If the internet is not working, the first thing to check is that
the black WiFi antennae are still upright and have not been knocked sideways.


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 Expo laptop 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.

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.

Two WiFi systems

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.

Nerding


Training weekend laptop in 2018

Expo requires so much nerding that it is part of the pre-expo training.

Expo laptop

The Expo laptop 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:


Basecamp computer in 1991 - in the old potato hut

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 Expo laptop first to see how it all works.

The laptop is usually connected to an extra LCD screen so that you can see surveys more easily as the laptop itself is small.

For experienced expo surveyers the Expo laptop 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 Expo laptop as the software is already set up (cryptographic key exchange etc. is pre-configured). See the Basic Expo Laptop for info on how to do that.

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.

At the end of expo we don't need to bring the Expo laptop 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.

Printing and Scanning

We have A4 printer and scanner attached via usb cables and a usb hub to the Expo laptop. 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 Expo laptop 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.

The Expo Laptops: Crowley's Friend: Aziraphale

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 expo laptop 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 expo laptop is called "Crowley". Crowley has a 64GB microSD card plugged into it which holds the local copy of /expofiles/ whereas Azirophale has a big enough solid-state drive (128GB, new for 2023) to hold /expofiles/ (and Azirophale's SD code slot doesn't work).

Both laptops have had RAM upgrades and solid-state disc upgrades.

Networking Hardware - experts only

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].


Hut Network - click to enlarge

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 .

The Expo laptops have a dynamic local address of this form, as does any other laptop connecting to this WiFi.

The Acer Aspire netbook ("tclaspire3") is on a static address 192.168.1.100.

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.

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

ssh expo@192.168.200.100
to run Mark Shinwell's script (re-edited by Sam 2019)
/root/fakenet/runfakenet
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 ssh doesn't work.

The Acer netbook needs to have its persistent networking set up correctly in addition to the script. This is the wicd 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.

Historical Note

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 expo.survex.com to be merged.

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.

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.


Go on to: Expo online systems