PyMaemo/Using Location API - Revision history

212.31.40.99: /* GPSDevice and GPSDeviceFix */

2017-02-22T17:14:49Z

GPSDevice and GPSDeviceFix

← Older revision		Revision as of 17:14, 22 February 2017
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	*<code>climb</code>: Current rate of climb in m/s (<code>location.GPS_DEVICE_CLIMB_SET</code>)		*<code>climb</code>: Current rate of climb in m/s (<code>location.GPS_DEVICE_CLIMB_SET</code>)
	*<code>epc</code>: Climb accuracy		*<code>epc</code>: Climb accuracy







	An application receiving a fix cannot know if the fix is a result from location method it requested. Therefore application should study whether fix is accurate enough to satisfy application's needs. This can be done by inspecting "<code>eph</code>" field, which is fix's horizontal accuracy in centimeters. Typical values for horizontal accuracies can be seen in the location methods table. If accuracy is not known, it has a value of NaN.		An application receiving a fix cannot know if the fix is a result from location method it requested. Therefore application should study whether fix is accurate enough to satisfy application's needs. This can be done by inspecting "<code>eph</code>" field, which is fix's horizontal accuracy in centimeters. Typical values for horizontal accuracies can be seen in the location methods table. If accuracy is not known, it has a value of NaN.

212.31.40.99: /* GPSDevice and GPSDeviceFix */

2017-02-22T17:13:17Z

GPSDevice and GPSDeviceFix

← Older revision		Revision as of 17:13, 22 February 2017
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	*<code>climb</code>: Current rate of climb in m/s (<code>location.GPS_DEVICE_CLIMB_SET</code>)		*<code>climb</code>: Current rate of climb in m/s (<code>location.GPS_DEVICE_CLIMB_SET</code>)
	*<code>epc</code>: Climb accuracy		*<code>epc</code>: Climb accuracy







	An application receiving a fix cannot know if the fix is a result from location method it requested. Therefore application should study whether fix is accurate enough to satisfy application's needs. This can be done by inspecting "<code>eph</code>" field, which is fix's horizontal accuracy in centimeters. Typical values for horizontal accuracies can be seen in the location methods table. If accuracy is not known, it has a value of NaN.		An application receiving a fix cannot know if the fix is a result from location method it requested. Therefore application should study whether fix is accurate enough to satisfy application's needs. This can be done by inspecting "<code>eph</code>" field, which is fix's horizontal accuracy in centimeters. Typical values for horizontal accuracies can be seen in the location methods table. If accuracy is not known, it has a value of NaN.

imported_>amigadave: spam: Undo revision 43000 by Shawnlee100 (Talk)

2011-04-11T13:34:15Z

spam: Undo revision 43000 by Shawnlee100 (Talk)

← Older revision		Revision as of 13:34, 11 April 2011
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	== Location intervals ==		== Location intervals ==

	Liblocation supports a default interval (equals to one second) and intervals of 1, 2, 5, 10, 20, 30, 60 and 120 seconds between fixes. Due to performance and power consumption reasons, all the intervals provide fixes only if position of the device has changed. Therefore the interval reflects more how often device checks for coordinate changes, than the actual interval between fixes. Nature of GPS fixes being constantly changing guarantees that GPS fixes are provided with requested interval. However, if there are several applications using different intervals, then the used interval is the minimum of intervals requested by all applications.~~[http://www.aboutquran.webs.com aboutquran]~~		Liblocation supports a default interval (equals to one second) and intervals of 1, 2, 5, 10, 20, 30, 60 and 120 seconds between fixes. Due to performance and power consumption reasons, all the intervals provide fixes only if position of the device has changed. Therefore the interval reflects more how often device checks for coordinate changes, than the actual interval between fixes. Nature of GPS fixes being constantly changing guarantees that GPS fixes are provided with requested interval. However, if there are several applications using different intervals, then the used interval is the minimum of intervals requested by all applications.

	Location interval is set as <code>GPSDControl</code>'s "preferred-interval" property:		Location interval is set as <code>GPSDControl</code>'s "preferred-interval" property:
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	control.set_properties(preferred_interval=location.INTERVAL_60S)		control.set_properties(preferred_interval=location.INTERVAL_60S)
	</source>		</source>

	== GPSDevice and GPSDeviceFix ==		== GPSDevice and GPSDeviceFix ==

imported_>shawnlee100: /* Location intervals */

2011-04-11T09:44:29Z

Location intervals

← Older revision		Revision as of 09:44, 11 April 2011
Line 61:		Line 61:
	== Location intervals ==		== Location intervals ==

	Liblocation supports a default interval (equals to one second) and intervals of 1, 2, 5, 10, 20, 30, 60 and 120 seconds between fixes. Due to performance and power consumption reasons, all the intervals provide fixes only if position of the device has changed. Therefore the interval reflects more how often device checks for coordinate changes, than the actual interval between fixes. Nature of GPS fixes being constantly changing guarantees that GPS fixes are provided with requested interval. However, if there are several applications using different intervals, then the used interval is the minimum of intervals requested by all applications.		Liblocation supports a default interval (equals to one second) and intervals of 1, 2, 5, 10, 20, 30, 60 and 120 seconds between fixes. Due to performance and power consumption reasons, all the intervals provide fixes only if position of the device has changed. Therefore the interval reflects more how often device checks for coordinate changes, than the actual interval between fixes. Nature of GPS fixes being constantly changing guarantees that GPS fixes are provided with requested interval. However, if there are several applications using different intervals, then the used interval is the minimum of intervals requested by all applications.[http://www.aboutquran.webs.com aboutquran]

	Location interval is set as <code>GPSDControl</code>'s "preferred-interval" property:		Location interval is set as <code>GPSDControl</code>'s "preferred-interval" property:
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	control.set_properties(preferred_interval=location.INTERVAL_60S)		control.set_properties(preferred_interval=location.INTERVAL_60S)
	</source>		</source>

	== GPSDevice and GPSDeviceFix ==		== GPSDevice and GPSDeviceFix ==

imported_>amigadave: add table caption, sprinkle


2011-03-02T09:27:37Z
add table caption, sprinkle <code>

				
				
				
				
				
				← Older revision
				Revision as of 09:27, 2 March 2011
				
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* <code>location.METHOD_AGNSS</code> (Assisted Global Navigation Satellite System) - A method for using GPS receiver with assistance data from external location server. A SIM card and a network connection is needed for AGNSS method. If no network connection or SIM card is available, this equals to GNSS. * <code>location.METHOD_AGNSS</code> (Assisted Global Navigation Satellite System) - A method for using GPS receiver with assistance data from external location server. A SIM card and a network connection is needed for AGNSS method. If no network connection or SIM card is available, this equals to GNSS.



Location resources are shared between applications, and applications can request different location methods. Fixes for all requested methods are sent for all applications listening to <code>GPSDevice</code>'s "changed" signal, therefore application should judge whether fix it is receiving, is one that it needs. See [[#GPSDevice and GPSDeviceFix|GPSDeviceFix]] section for discussion. Location resources are shared between applications, and applications can request different location methods. Fixes for all requested methods are sent for all applications listening to <code>GPSDevice</code>'s "<code>changed</code>" signal, therefore application should judge whether fix it is receiving, is one that it needs. See [[#GPSDevice and GPSDeviceFix|GPSDeviceFix]] section for discussion.



If device is set for bluetooth GPS from control panel, it can used for locationing via USER_SELECTED, AGNSS and GNSS methods. In this case AGNSS and GNSS do not differ, because assistance server cannot be utilized. If device is set for bluetooth GPS from control panel, it can used for locationing via USER_SELECTED, AGNSS and GNSS methods. In this case AGNSS and GNSS do not differ, because assistance server cannot be utilized.
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Here is table that summarizes differences between the methods. Accuracy refers to horizontal accuracy of the fix. Here is table that summarizes differences between the methods. Accuracy refers to horizontal accuracy of the fix.



{| class="wikitable" style="margin: 1em auto 1em auto" {| class="wikitable"
|+ Available location methods
|-
! Method !! Typical accuracy !! Requires SIM !! Requires network !! Drains battery ! Method !! Typical accuracy !! Requires SIM !! Requires network !! Drains battery
|- |-
| CWP || 1km-1000km || Yes || No || No | CWP || 1 - 1000 km || Yes || No || No
|- |-
| ACWP || 1km-10km || Yes || Yes || No | ACWP || 1 - 10 km || Yes || Yes || No
|- |-
| GNSS || 5m-100m || No	|| No || Yes | GNSS || 5 - 100 m || No	|| No || Yes
|- |-
| AGNSS || 5m-100m || Yes || Yes || Yes | AGNSS || 5 - 100 m || Yes || Yes || Yes
|} |}



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== GPSDevice and GPSDeviceFix == == GPSDevice and GPSDeviceFix ==



<code>GPSDevice</code> object has the following attributes ('''FIXME:''' currently "satellites" and "cell_info" attributes are not supported in Python): <code>GPSDevice</code> object has the following attributes ('''FIXME:''' currently "<code>satellites</code>" and "<code>cell_info</code>" attributes are not supported in Python):
*online: Whether there is a connection to the hardware *<code>online</code>: Whether there is a connection to the hardware
*status: Status of the device *<code>status</code>: Status of the device
*fix: Tuple containing actual fix data (latitude, longitude, etc) *<code>fix</code>: Tuple containing actual fix data (latitude, longitude, etc)
*satellites_in_view: Number of satellites in view *<code>satellites_in_view</code>: Number of satellites in view
*satellites_in_use: Number of satellites in use *<code>satellites_in_use</code>: Number of satellites in use
*satellites: Tuple containing information about satellites *<code>satellites</code>: Tuple containing information about satellites
*cell_info: Tuple containing information about cell the device is connected to *<code>cell_info</code>: Tuple containing information about cell the device is connected to



The most useful attribute is naturally the "fix" tuple which contains position and movement of the device and accuracies for them. The available information is listed below (in the order they appear on the tuple). In parenthesis there is a identifier which can be bitwisely anded with the "fields" value, to see whether corresponding tuple value is set. The most useful attribute is naturally the "<code>fix</code>" tuple which contains position and movement of the device and accuracies for them. The available information is listed below (in the order they appear on the tuple). In parenthesis there is a identifier which can be bitwisely anded with the "fields" value, to see whether corresponding tuple value is set.



*mode: The mode of the fix *<code>mode</code>: The mode of the fix
*fields: A bitfield representing which items of this tuple contain valid data *<code>fields</code>: A bitfield representing which items of this tuple contain valid data
*time: The timestamp of the update (<code>location.GPS_DEVICE_TIME_SET</code>) *<code>time</code>: The timestamp of the update (<code>location.GPS_DEVICE_TIME_SET</code>)
*ept: Time accuracy *<code>ept</code>: Time accuracy
*latitude: Fix latitude (<code>location.GPS_DEVICE_LATLONG_SET</code>) *<code>latitude</code>: Fix latitude (<code>location.GPS_DEVICE_LATLONG_SET</code>)
*longitude: Fix longitude (<code>location.GPS_DEVICE_LATLONG_SET</code>) *<code>longitude</code>: Fix longitude (<code>location.GPS_DEVICE_LATLONG_SET</code>)
*eph: Horizontal position accuracy *<code>eph</code>: Horizontal position accuracy
*altitude: Fix altitude in meters (<code>location.GPS_DEVICE_ALTITUDE_SET</code>) *<code>altitude</code>: Fix altitude in meters (<code>location.GPS_DEVICE_ALTITUDE_SET</code>)
*double epv: Vertical position accuracy *double <code>epv</code>: Vertical position accuracy
*track: Direction of motion in degrees (<code>location.GPS_DEVICE_TRACK_SET</code>) *<code>track</code>: Direction of motion in degrees (<code>location.GPS_DEVICE_TRACK_SET</code>)
*epd: Track accuracy *<code>epd</code>: Track accuracy
*speed: Current speed in km/h (<code>location.GPS_DEVICE_SPEED_SET</code>) *<code>speed</code>: Current speed in km/h (<code>location.GPS_DEVICE_SPEED_SET</code>)
*eps: Speed accuracy *<code>eps</code>: Speed accuracy
*climb: Current rate of climb in m/s (<code>location.GPS_DEVICE_CLIMB_SET</code>) *<code>climb</code>: Current rate of climb in m/s (<code>location.GPS_DEVICE_CLIMB_SET</code>)
*epc: Climb accuracy *<code>epc</code>: Climb accuracy



An application receiving a fix cannot know if the fix is a result from location method it requested. Therefore application should study whether fix is accurate enough to satisfy application's needs. This can be done by inspecting "eph" field, which is fix's horizontal accuracy in centimeters. Typical values for horizontal accuracies can be seen in the location methods table. If accuracy is not known, it has a value of NaN. An application receiving a fix cannot know if the fix is a result from location method it requested. Therefore application should study whether fix is accurate enough to satisfy application's needs. This can be done by inspecting "<code>eph</code>" field, which is fix's horizontal accuracy in centimeters. Typical values for horizontal accuracies can be seen in the location methods table. If accuracy is not known, it has a value of NaN.



== Liblocation signals and callbacks == == Liblocation signals and callbacks ==
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     print "Satellites in view: %d, in use: %d" % (device.satellites_in_view, device.satellites_in_use)      print "Satellites in view: %d, in use: %d" % (device.satellites_in_view, device.satellites_in_use)
</source> </source>
Liblocation sends a "changed" signal also after locationing is started or stopped, in which case a last known fix is sent if such exists. Application can differentiate these fixes from real ones by inspecting <code>device.status</code> attribute which equals <code>location.GPS_DEVICE_STATUS_NO_FIX</code> if the fix is not real. Liblocation sends a "<code>changed</code>" signal also after locationing is started or stopped, in which case a last known fix is sent if such exists. Application can differentiate these fixes from real ones by inspecting <code>device.status</code> attribute which equals <code>location.GPS_DEVICE_STATUS_NO_FIX</code> if the fix is not real.



== Starting and stopping locationing == == Starting and stopping locationing ==



imported_>erroneus: /* Complete example */
2010-07-17T00:57:42Z
Complete example

				
				
				
				
				
				← Older revision
				Revision as of 00:57, 17 July 2010
				
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         if device.fix[1] & location.GPS_DEVICE_LATLONG_SET:          if device.fix[1] & location.GPS_DEVICE_LATLONG_SET:
             print "lat = %f, long = %f" % device.fix[4:6]              print "lat = %f, long = %f" % device.fix[4:6]
             data.stop()              # data.stop() commented out to allow continuous loop for a reliable fix - press ctrl c to break the loop, or program your own way of exiting)



def on_stop(control, data): def on_stop(control, data):



190.17.97.168: /* Using liblocation from Python */
2010-07-09T16:37:04Z
Using liblocation from Python

				
				
				
				
				
				← Older revision
				Revision as of 16:37, 9 July 2010
				
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import location import location
</source> </source>
Liblocation has two public <code>GObject</code>s. <code>GPSDControl</code. is used for starting and stopping of location services, setting location method and interval, and listening for errors. <code>GPSDevice</code> has information about device status and contains the actual fix when one exists. The two <code>GObjects</code> are initiated as follows. Liblocation has two public <code>GObject</code>s. <code>GPSDControl</code>. is used for starting and stopping of location services, setting location method and interval, and listening for errors. <code>GPSDevice</code> has information about device status and contains the actual fix when one exists. The two <code>GObjects</code> are initiated as follows.
<source lang="python"> <source lang="python">
control = location.GPSDControl.get_default() control = location.GPSDControl.get_default()
device = location.GPSDevice() device = location.GPSDevice()
</source> </source>

== Location methods == == Location methods ==






imported_>oriolj: /* Location methods */
2010-06-24T08:36:57Z
Location methods

				
				
				
				
				
				← Older revision
				Revision as of 08:36, 24 June 2010
				
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* <code>location.METHOD_ACWP</code> (Assisted Complementary Wireless Positioning) - A method where device is located based on cellular base station to which device is registered to. SIM card and a network connection is needed for ACWP method. If no network connection is available, this equals to CWP. Application might receive MCC fixes before base station information from external location server is fetched and as a fallback if e.g. network is temporary unavailable. * <code>location.METHOD_ACWP</code> (Assisted Complementary Wireless Positioning) - A method where device is located based on cellular base station to which device is registered to. SIM card and a network connection is needed for ACWP method. If no network connection is available, this equals to CWP. Application might receive MCC fixes before base station information from external location server is fetched and as a fallback if e.g. network is temporary unavailable.
* <code>location.METHOD_GNSS</code> (Global Navigation Satellite System) - A method for using GPS receiver. Typically time for the first fix is significantly longer than with AGNSS. Neither SIM card nor network connection is needed for GNSS method, and GNSS can even be used in offline mode. * <code>location.METHOD_GNSS</code> (Global Navigation Satellite System) - A method for using GPS receiver. Typically time for the first fix is significantly longer than with AGNSS. Neither SIM card nor network connection is needed for GNSS method, and GNSS can even be used in offline mode.
* <code>location.METHOD_AGNSS</code (Assisted Global Navigation Satellite System) - A method for using GPS receiver with assistance data from external location server. A SIM card and a network connection is needed for AGNSS method. If no network connection or SIM card is available, this equals to GNSS. * <code>location.METHOD_AGNSS</code> (Assisted Global Navigation Satellite System) - A method for using GPS receiver with assistance data from external location server. A SIM card and a network connection is needed for AGNSS method. If no network connection or SIM card is available, this equals to GNSS.



Location resources are shared between applications, and applications can request different location methods. Fixes for all requested methods are sent for all applications listening to <code>GPSDevice</code>'s "changed" signal, therefore application should judge whether fix it is receiving, is one that it needs. See [[#GPSDevice and GPSDeviceFix|GPSDeviceFix]] section for discussion. Location resources are shared between applications, and applications can request different location methods. Fixes for all requested methods are sent for all applications listening to <code>GPSDevice</code>'s "changed" signal, therefore application should judge whether fix it is receiving, is one that it needs. See [[#GPSDevice and GPSDeviceFix|GPSDeviceFix]] section for discussion.



imported_>amigadave: use  and 

2010-06-23T10:18:00Z
use <source> and <code>
Show changes


imported_>lizardo: /* Complete example */
2010-01-27T12:13:49Z
Complete example

				
				
				
				
				
				← Older revision
				Revision as of 12:13, 27 January 2010
				
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  run-standalone.sh python2.5 test.py   run-standalone.sh python2.5 test.py



<b>Important:</b> do not name your script "location.py". Otherwise, Python will try to import it as a module, instead of the correct "location" module, and you will get errors like:

 Traceback (most recent call last):
 File "location.py", line 1, in <module>
 import location
 File "/home/user/location.py", line 25, in <module>
 control = location.GPSDControl.get_default()
 AttributeError: 'module' object has no attribute 'GPSDControl'



[[Category:Python]] [[Category:Python]]

← Older revision		Revision as of 09:27, 2 March 2011
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	* <code>location.METHOD_AGNSS</code> (Assisted Global Navigation Satellite System) - A method for using GPS receiver with assistance data from external location server. A SIM card and a network connection is needed for AGNSS method. If no network connection or SIM card is available, this equals to GNSS.		* <code>location.METHOD_AGNSS</code> (Assisted Global Navigation Satellite System) - A method for using GPS receiver with assistance data from external location server. A SIM card and a network connection is needed for AGNSS method. If no network connection or SIM card is available, this equals to GNSS.

	Location resources are shared between applications, and applications can request different location methods. Fixes for all requested methods are sent for all applications listening to <code>GPSDevice</code>'s "changed" signal, therefore application should judge whether fix it is receiving, is one that it needs. See [[#GPSDevice and GPSDeviceFix\|GPSDeviceFix]] section for discussion.		Location resources are shared between applications, and applications can request different location methods. Fixes for all requested methods are sent for all applications listening to <code>GPSDevice</code>'s "<code>changed</code>" signal, therefore application should judge whether fix it is receiving, is one that it needs. See [[#GPSDevice and GPSDeviceFix\|GPSDeviceFix]] section for discussion.

	If device is set for bluetooth GPS from control panel, it can used for locationing via USER_SELECTED, AGNSS and GNSS methods. In this case AGNSS and GNSS do not differ, because assistance server cannot be utilized.		If device is set for bluetooth GPS from control panel, it can used for locationing via USER_SELECTED, AGNSS and GNSS methods. In this case AGNSS and GNSS do not differ, because assistance server cannot be utilized.
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	Here is table that summarizes differences between the methods. Accuracy refers to horizontal accuracy of the fix.		Here is table that summarizes differences between the methods. Accuracy refers to horizontal accuracy of the fix.

	{\| class="wikitable" ~~style="margin: 1em auto 1em auto"~~		{\| class="wikitable"
			\|+ Available location methods
			\|-
	! Method !! Typical accuracy !! Requires SIM !! Requires network !! Drains battery		! Method !! Typical accuracy !! Requires SIM !! Requires network !! Drains battery
	\|-		\|-
	\| CWP \|\| ~~1km~~-~~1000km~~ \|\| Yes \|\| No \|\| No		\| CWP \|\| 1 - 1000 km \|\| Yes \|\| No \|\| No
	\|-		\|-
	\| ACWP \|\| ~~1km~~-~~10km~~ \|\| Yes \|\| Yes \|\| No		\| ACWP \|\| 1 - 10 km \|\| Yes \|\| Yes \|\| No
	\|-		\|-
	\| GNSS \|\| 5m-~~100m~~ \|\| No \|\| No \|\| Yes		\| GNSS \|\| 5 - 100 m \|\| No \|\| No \|\| Yes
	\|-		\|-
	\| AGNSS \|\| 5m-~~100m~~ \|\| Yes \|\| Yes \|\| Yes		\| AGNSS \|\| 5 - 100 m \|\| Yes \|\| Yes \|\| Yes
	\|}		\|}

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	== GPSDevice and GPSDeviceFix ==		== GPSDevice and GPSDeviceFix ==

	<code>GPSDevice</code> object has the following attributes ('''FIXME:''' currently "satellites" and "cell_info" attributes are not supported in Python):		<code>GPSDevice</code> object has the following attributes ('''FIXME:''' currently "<code>satellites</code>" and "<code>cell_info</code>" attributes are not supported in Python):
	*online: Whether there is a connection to the hardware		*<code>online</code>: Whether there is a connection to the hardware
	*status: Status of the device		*<code>status</code>: Status of the device
	*fix: Tuple containing actual fix data (latitude, longitude, etc)		*<code>fix</code>: Tuple containing actual fix data (latitude, longitude, etc)
	*satellites_in_view: Number of satellites in view		*<code>satellites_in_view</code>: Number of satellites in view
	*satellites_in_use: Number of satellites in use		*<code>satellites_in_use</code>: Number of satellites in use
	*satellites: Tuple containing information about satellites		*<code>satellites</code>: Tuple containing information about satellites
	*cell_info: Tuple containing information about cell the device is connected to		*<code>cell_info</code>: Tuple containing information about cell the device is connected to

	The most useful attribute is naturally the "fix" tuple which contains position and movement of the device and accuracies for them. The available information is listed below (in the order they appear on the tuple). In parenthesis there is a identifier which can be bitwisely anded with the "fields" value, to see whether corresponding tuple value is set.		The most useful attribute is naturally the "<code>fix</code>" tuple which contains position and movement of the device and accuracies for them. The available information is listed below (in the order they appear on the tuple). In parenthesis there is a identifier which can be bitwisely anded with the "fields" value, to see whether corresponding tuple value is set.

	*mode: The mode of the fix		*<code>mode</code>: The mode of the fix
	*fields: A bitfield representing which items of this tuple contain valid data		*<code>fields</code>: A bitfield representing which items of this tuple contain valid data
	*time: The timestamp of the update (<code>location.GPS_DEVICE_TIME_SET</code>)		*<code>time</code>: The timestamp of the update (<code>location.GPS_DEVICE_TIME_SET</code>)
	*ept: Time accuracy		*<code>ept</code>: Time accuracy
	*latitude: Fix latitude (<code>location.GPS_DEVICE_LATLONG_SET</code>)		*<code>latitude</code>: Fix latitude (<code>location.GPS_DEVICE_LATLONG_SET</code>)
	*longitude: Fix longitude (<code>location.GPS_DEVICE_LATLONG_SET</code>)		*<code>longitude</code>: Fix longitude (<code>location.GPS_DEVICE_LATLONG_SET</code>)
	*eph: Horizontal position accuracy		*<code>eph</code>: Horizontal position accuracy
	*altitude: Fix altitude in meters (<code>location.GPS_DEVICE_ALTITUDE_SET</code>)		*<code>altitude</code>: Fix altitude in meters (<code>location.GPS_DEVICE_ALTITUDE_SET</code>)
	*double epv: Vertical position accuracy		*double <code>epv</code>: Vertical position accuracy
	*track: Direction of motion in degrees (<code>location.GPS_DEVICE_TRACK_SET</code>)		*<code>track</code>: Direction of motion in degrees (<code>location.GPS_DEVICE_TRACK_SET</code>)
	*epd: Track accuracy		*<code>epd</code>: Track accuracy
	*speed: Current speed in km/h (<code>location.GPS_DEVICE_SPEED_SET</code>)		*<code>speed</code>: Current speed in km/h (<code>location.GPS_DEVICE_SPEED_SET</code>)
	*eps: Speed accuracy		*<code>eps</code>: Speed accuracy
	*climb: Current rate of climb in m/s (<code>location.GPS_DEVICE_CLIMB_SET</code>)		*<code>climb</code>: Current rate of climb in m/s (<code>location.GPS_DEVICE_CLIMB_SET</code>)
	*epc: Climb accuracy		*<code>epc</code>: Climb accuracy

	An application receiving a fix cannot know if the fix is a result from location method it requested. Therefore application should study whether fix is accurate enough to satisfy application's needs. This can be done by inspecting "eph" field, which is fix's horizontal accuracy in centimeters. Typical values for horizontal accuracies can be seen in the location methods table. If accuracy is not known, it has a value of NaN.		An application receiving a fix cannot know if the fix is a result from location method it requested. Therefore application should study whether fix is accurate enough to satisfy application's needs. This can be done by inspecting "<code>eph</code>" field, which is fix's horizontal accuracy in centimeters. Typical values for horizontal accuracies can be seen in the location methods table. If accuracy is not known, it has a value of NaN.

	== Liblocation signals and callbacks ==		== Liblocation signals and callbacks ==
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	print "Satellites in view: %d, in use: %d" % (device.satellites_in_view, device.satellites_in_use)		print "Satellites in view: %d, in use: %d" % (device.satellites_in_view, device.satellites_in_use)
	</source>		</source>
	Liblocation sends a "changed" signal also after locationing is started or stopped, in which case a last known fix is sent if such exists. Application can differentiate these fixes from real ones by inspecting <code>device.status</code> attribute which equals <code>location.GPS_DEVICE_STATUS_NO_FIX</code> if the fix is not real.		Liblocation sends a "<code>changed</code>" signal also after locationing is started or stopped, in which case a last known fix is sent if such exists. Application can differentiate these fixes from real ones by inspecting <code>device.status</code> attribute which equals <code>location.GPS_DEVICE_STATUS_NO_FIX</code> if the fix is not real.

	== Starting and stopping locationing ==		== Starting and stopping locationing ==

← Older revision		Revision as of 00:57, 17 July 2010
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	if device.fix[1] & location.GPS_DEVICE_LATLONG_SET:		if device.fix[1] & location.GPS_DEVICE_LATLONG_SET:
	print "lat = %f, long = %f" % device.fix[4:6]		print "lat = %f, long = %f" % device.fix[4:6]
	data.stop()		# data.stop() commented out to allow continuous loop for a reliable fix - press ctrl c to break the loop, or program your own way of exiting)

	def on_stop(control, data):		def on_stop(control, data):

← Older revision		Revision as of 16:37, 9 July 2010
Line 11:		Line 11:
	import location		import location
	</source>		</source>
	Liblocation has two public <code>GObject</code>s. <code>GPSDControl</code. is used for starting and stopping of location services, setting location method and interval, and listening for errors. <code>GPSDevice</code> has information about device status and contains the actual fix when one exists. The two <code>GObjects</code> are initiated as follows.		Liblocation has two public <code>GObject</code>s. <code>GPSDControl</code>. is used for starting and stopping of location services, setting location method and interval, and listening for errors. <code>GPSDevice</code> has information about device status and contains the actual fix when one exists. The two <code>GObjects</code> are initiated as follows.
	<source lang="python">		<source lang="python">
	control = location.GPSDControl.get_default()		control = location.GPSDControl.get_default()
	device = location.GPSDevice()		device = location.GPSDevice()
	</source>		</source>

	== Location methods ==		== Location methods ==

← Older revision		Revision as of 08:36, 24 June 2010
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	* <code>location.METHOD_ACWP</code> (Assisted Complementary Wireless Positioning) - A method where device is located based on cellular base station to which device is registered to. SIM card and a network connection is needed for ACWP method. If no network connection is available, this equals to CWP. Application might receive MCC fixes before base station information from external location server is fetched and as a fallback if e.g. network is temporary unavailable.		* <code>location.METHOD_ACWP</code> (Assisted Complementary Wireless Positioning) - A method where device is located based on cellular base station to which device is registered to. SIM card and a network connection is needed for ACWP method. If no network connection is available, this equals to CWP. Application might receive MCC fixes before base station information from external location server is fetched and as a fallback if e.g. network is temporary unavailable.
	* <code>location.METHOD_GNSS</code> (Global Navigation Satellite System) - A method for using GPS receiver. Typically time for the first fix is significantly longer than with AGNSS. Neither SIM card nor network connection is needed for GNSS method, and GNSS can even be used in offline mode.		* <code>location.METHOD_GNSS</code> (Global Navigation Satellite System) - A method for using GPS receiver. Typically time for the first fix is significantly longer than with AGNSS. Neither SIM card nor network connection is needed for GNSS method, and GNSS can even be used in offline mode.
	* <code>location.METHOD_AGNSS</code (Assisted Global Navigation Satellite System) - A method for using GPS receiver with assistance data from external location server. A SIM card and a network connection is needed for AGNSS method. If no network connection or SIM card is available, this equals to GNSS.		* <code>location.METHOD_AGNSS</code> (Assisted Global Navigation Satellite System) - A method for using GPS receiver with assistance data from external location server. A SIM card and a network connection is needed for AGNSS method. If no network connection or SIM card is available, this equals to GNSS.

	Location resources are shared between applications, and applications can request different location methods. Fixes for all requested methods are sent for all applications listening to <code>GPSDevice</code>'s "changed" signal, therefore application should judge whether fix it is receiving, is one that it needs. See [[#GPSDevice and GPSDeviceFix\|GPSDeviceFix]] section for discussion.		Location resources are shared between applications, and applications can request different location methods. Fixes for all requested methods are sent for all applications listening to <code>GPSDevice</code>'s "changed" signal, therefore application should judge whether fix it is receiving, is one that it needs. See [[#GPSDevice and GPSDeviceFix\|GPSDeviceFix]] section for discussion.

← Older revision		Revision as of 12:13, 27 January 2010
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	run-standalone.sh python2.5 test.py		run-standalone.sh python2.5 test.py

			<b>Important:</b> do not name your script "location.py". Otherwise, Python will try to import it as a module, instead of the correct "location" module, and you will get errors like:

			Traceback (most recent call last):
			File "location.py", line 1, in <module>
			import location
			File "/home/user/location.py", line 25, in <module>
			control = location.GPSDControl.get_default()
			AttributeError: 'module' object has no attribute 'GPSDControl'

	[[Category:Python]]		[[Category:Python]]