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7 <title>Village DTN Router - User Interface</title> |
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12 <h1>Village DTN Router - Hardware User Interface</h1> |
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13 |
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14 <p>stephen.farrell@cs.tcd.ie, 2010-05-27</p> |
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15 |
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16 <p>This document describes the external user interface of the village DTN |
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17 router box. That is: how to interpret the contents displayed on the screen and |
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18 how to turn the device on and off safely.</p> |
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19 |
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20 <p>The first thing to note is that users should only use the device as shown |
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21 here - <strong>ONLY TRAINED STAFF SHOULD ATTEMPT OTHER ACTIONS</strong>, so |
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22 please do not disturb cables, antennae or other external parts of the device. |
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23 Any such tampering is likely to result in an non-functional village DTN router |
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24 so please don't do it!</p> |
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25 |
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26 <p>Figure 1 shows a village DTN router deployed in Staloluokta in 2009.</p> |
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27 |
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28 <h2>Turning On and Off</h2> |
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29 |
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30 <p>The large switch at the side of the device is used to turn it on and off. |
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31 The device requries approximately two minutes to fully boot and bring up all of |
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32 the WiFi, mail and web services. <strong>PLEASE BE PATIENT - DO NOT CONSTANTLY |
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33 SWITCH THE DEVICE ON AND OFF!</strong> Doing so could damage the device, in |
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34 particular, the filesystems - such an error would be the equivalent of a |
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35 hard-disk failure in a laptop.</p> |
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36 |
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37 <p>Figure 2 shows the ON/OFF switch in the "ON" position. </p> |
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38 |
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39 <p>Figure 3 shows the ON/OFF switch in the "OFF" position.</p> |
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40 |
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41 <p>Figure 4 shows a user switch the device to the "ON" position.</p> |
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42 |
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43 <p>That's all very simple so far, but its gets a little more complicated when |
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44 we need to understand how the device manages its use of power.</p> |
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45 |
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46 <h2>Power Management</h2> |
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47 |
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48 <p>As a solar-powered device, the village DTN router must manage its power so |
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49 as to conserve battery in case there is not sufficient sunlight to charge the |
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50 batteries. We have implemented a power management module for the village DTN |
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51 router with the following features:</p> |
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52 <ul> |
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53 <li>When sufficient power is available and the device is operating normally, |
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54 it is in the "UP" state. In the "UP" state, all WiFi, mail and web services |
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55 are operating.</li> |
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56 <li>When power levels are lower, the device may switch to a standby mode of |
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57 operation for a short period (30 minutes) to allow some time for the |
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58 batteries to recharge, this is the "STANDBY-SHORT" state. In this state the |
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59 device uses much less power, but no services are available as the processor |
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60 in the device is asleep, just like a laptop in standby mode. After 30 |
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61 minutes, the device will power up, and if power levels are sufficient will |
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62 change to the "UP" state.</li> |
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63 <li>If power levels fall further, the device will </li> |
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64 </ul> |
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65 |
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66 <p></p> |
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67 |
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68 <p></p> |
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