diff -r 47d07dc86cd0 -r 1d832a05eb87 router-screen.html --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/router-screen.html Thu May 27 15:03:28 2010 +0100 @@ -0,0 +1,70 @@ + + + + + + Village DTN Router - User Interface + + + + +

Village DTN Router - Hardware User Interface

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stephen.farrell@cs.tcd.ie, 2010-05-27

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This document describes the external user interface of the village DTN +router box. That is: how to interpret the contents displayed on the screen and +how to turn the device on and off safely.

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The first thing to note is that users should only use the device as shown +here - ONLY TRAINED STAFF SHOULD ATTEMPT OTHER ACTIONS, so +please do not disturb cables, antennae or other external parts of the device. +Any such tampering is likely to result in an non-functional village DTN router +so please don't do it!

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Figure 1 shows a village DTN router deployed in Staloluokta in 2009.

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Turning On and Off

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The large switch at the side of the device is used to turn it on and off. +The device requries approximately two minutes to fully boot and bring up all of +the WiFi, mail and web services. PLEASE BE PATIENT - DO NOT CONSTANTLY +SWITCH THE DEVICE ON AND OFF! Doing so could damage the device, in +particular, the filesystems - such an error would be the equivalent of a +hard-disk failure in a laptop.

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Figure 2 shows the ON/OFF switch in the "ON" position.

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Figure 3 shows the ON/OFF switch in the "OFF" position.

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Figure 4 shows a user switch the device to the "ON" position.

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That's all very simple so far, but its gets a little more complicated when +we need to understand how the device manages its use of power.

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Power Management

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As a solar-powered device, the village DTN router must manage its power so +as to conserve battery in case there is not sufficient sunlight to charge the +batteries. We have implemented a power management module for the village DTN +router with the following features:

When sufficient power is available and the device is operating normally, + it is in the "UP" state. In the "UP" state, all WiFi, mail and web services + are operating.
When power levels are lower, the device may switch to a standby mode of + operation for a short period (30 minutes) to allow some time for the + batteries to recharge, this is the "STANDBY-SHORT" state. In this state the + device uses much less power, but no services are available as the processor + in the device is asleep, just like a laptop in standby mode. After 30 + minutes, the device will power up, and if power levels are sufficient will + change to the "UP" state.
If power levels fall further, the device will

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