forked from FOSS/BangleApps
64 lines
1.9 KiB
Markdown
64 lines
1.9 KiB
Markdown
# GPS Service
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A configurable, low power GPS widget that runs in the background.
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## Goals
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To develop a low power GPS widget that runs in the background and to
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facilitate an OS grid reference display in a watch face.
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* An app that turns on the GPS and constantly displays the screen
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will use around 75mA, the battery will last between 3-4 hours.
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* Using the GPS in a Widget in Super-E Power Saving Mode (PSM) with
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the screen off most of the time, will consume around 35mA and you
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might get 10hrs before a recharge.
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* Using the GPS in Power Saving Mode On/Off (PSMOO) with suitable
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settings can reduce the average consumption to around 15mA. A
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simple test using a 120s update period, 6s search period was still
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running with 45% battery 20 hours after it started.
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## Settings
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The Settings App enables you set the following options for the GPS
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Service. Go to Settings, select App/Widgets and then 'GPS Service'.
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* GPS - On/Off. When this value is changed the GPS Service will be
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powered on or off and the GPS Widget will be displayed.
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* Power Mode:
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** Super-E - the factory default setup for the GPS. The
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recommended power saving mode.
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** PSMOO - On/Off power saving mode. Configured by interval and
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search time. Choose this mode if you are happy to get a GPS
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position update less often (say every 1 or 2 minutes). The longer
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the interval the more time the GPS will spend sleeping in low
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power mode (7mA) between obtaining fixes (35mA). For walking in
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open country an update once every 60 seconds is adequate to put
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you within a 6 digit grid refernce sqaure.
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## Screenshots
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* GPS Watch face
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* Grid Reference Watch face
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## To Do List
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* add a logging option with options for interval between log points
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* add graphics and icons to the watch faces to make them look nicer
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## References
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* data sheet
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* power saving PDF
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* other code
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