Accelerometers - Revision history

amigadave: fix double redirect

2010-06-16T14:12:00Z

fix double redirect

← Older revision		Revision as of 14:12, 16 June 2010
Line 1:		Line 1:
-	#REDIRECT [[N900 ~~Hardware Accelerometer~~]]	+	#REDIRECT [[N900 accelerometer]]

amigadave: redirect to N900 Hardware Accelerometer

2010-06-14T13:42:33Z

redirect to N900 Hardware Accelerometer

← Older revision		Revision as of 13:42, 14 June 2010
Line 1:		Line 1:
-	~~[[Open development/Maemo roadmap/Fremantle\|Fremantle]] provides an accelerometer API. There are currently [https://bugs.maemo.org/show_bug.cgi?id=4724 two interfaces available]:~~	+	#REDIRECT [[N900 Hardware Accelerometer]]
-	# ~~D-Bus~~	+
-	~~# sysfs~~	+
-		+
-	~~See also the~~ [~~http://talk.maemo.org/showthread.php?p=288990 related thread] at talk.maemo.org.~~	+
-		+
-	~~== D-Bus ==~~	+
-		+
-	~~Thomas Thurman (~~[http://twitter.com/marnanel marnanel]) has put together a simple demo of an application using accelerometers using the D-Bus interface. You can find sources and .deb up at http://people.collabora.co.uk/~tthurman/sandcastle/	+
-		+
-	~~== sysfs ==~~	+
-		+
-	~~Another way is to use the sysfs file information:~~	+
-		+
-	~~/sys/class/i2c-adapter/i2c-3/3-001d/coord~~	+
-		+
-	~~When reading that file you get 3 values X, Y and Z (provided on one line, separated by white space). Values are in mG (milli G). 1000 = 1 G~~	+
-		+
-	~~{\| class="wikitable"~~	+
-	\|-	+
-	~~! Position~~	+
-	~~! X~~	+
-	~~! Y~~	+
-	~~! Z~~	+
-	\|-	+
-	~~\| Lying on table (back down)~~	+
-	~~\| 0~~	+
-	~~\| 0~~	+
-	~~\| -1000~~	+
-	\|-	+
-	~~\| Lying on table (face down)~~	+
-	~~\| 0~~	+
-	~~\| 0~~	+
-	~~\| 1000~~	+
-	\|-	+
-	~~\| Sitting on table (bottom edge down)~~	+
-	~~\| 0~~	+
-	~~\| -1000~~	+
-	~~\| 0~~	+
-	\|-	+
-	~~\| Sitting on table (right edge down)~~	+
-	~~\| -1000~~	+
-	~~\| 0~~	+
-	~~\| 0~~	+
-	\|-	+
-	~~\| Sitting on table (left edge down)~~	+
-	~~\| 1000~~	+
-	~~\| 0~~	+
-	~~\| 0~~	+
-	\|-	+
-	~~\| Bottom right corner down (approx.)~~	+
-	~~\| -707~~	+
-	~~\| -707~~	+
-	~~\| 0~~	+
-	\|}	+
-		+
-	~~These are theoretical values. In real life your mileage will vary.~~	+
-		+
-	~~An example can be found at: [http://git.zimmerle.org/?p=inclinometer.git;a=summary]~~	+
-		+
-	~~== Using the data ==~~	+
-		+
-	~~The ''X'' and ''Y'' values can be used to calculate<ref>Tom Pycke, ''[http://tom.pycke.be/mav/69/accelerometer-to-attitude~~ Accelerometer ~~to pitch and roll]''</ref> the pitch (that is, clockwise rotation) using the ''atan2'' function (note the inverted sign of ''y''):~~	+
-		+
-	~~angle_in_radians = '''atan2'''(''x'', -''y'')~~	+
-		+
-	~~Similar, ''Y'' and ''Z'' can be used to calculate the roll:~~	+
-		+
-	~~angle_in_radians = '''atan2'''(''y'', -''z'')~~	+
-		+
-	~~== Python ==~~	+
-		+
-	~~Using the sysfs interface:~~	+
-	~~<source lang="python">~~	+
-	~~def get_rotation():~~	+
-	~~f = open("/sys/class/i2c-adapter/i2c-3/3-001d/coord", 'r' )~~	+
-	~~coords = [int(w) for w in f.readline().split()]~~	+
-	~~f.close()~~	+
-	~~return coords~~	+
-	~~</source>~~	+
-		+
-	~~And using the D-Bus interface:~~	+
-	~~<source lang="python">~~	+
-	~~import dbus~~	+
-	~~bus = dbus.SystemBus()~~	+
-	~~accel = bus.get_object('com.nokia.mce',~~	+
-	~~'/com/nokia/mce/request',~~	+
-	~~'com.nokia.mce.request')~~	+
-	~~orientation , stand , face , x , y , z = accel.get_device_orientation()~~	+
-	~~</source>~~	+
-	x,y,z are the raw accelerometer measurements values, and the first three variables give text information about the device orientation. In particular, the first one informs about the landscape/portrait state.	+
-		+
-	~~== Smoothed C interface ==~~	+
-		+
-	~~This is a C function which returns smooth values from the accelerometer.~~	+
-	~~Designed for applications running at >=25fps (otherwise it lags)~~	+
-		+
-	~~(GPL code extracted from libliqbase: liqaccel.c)~~	+
-		+
-	~~<source lang="c">~~	+
-	~~static int ocnt=0;~~	+
-	~~static int oax=0;~~	+
-	~~static int oay=0;~~	+
-	~~static int oaz=0;~~	+
-		+
-	~~static const char *accel_filename = "/sys/class/i2c-adapter/i2c-3/3-001d/coord";~~	+
-		+
-	~~int liqaccel_read(int ax,int ay,int *az)~~	+
-	{	+
-	~~FILE *fd;~~	+
-	~~int rs;~~	+
-	~~fd = fopen(accel_filename, "r");~~	+
-	~~if(fd==NULL){ liqapp_log("liqaccel, cannot open for reading"); return -1;}~~	+
-	~~rs=fscanf((FILE*) fd,"%i %i %i",ax,ay,az);~~	+
-	~~fclose(fd);~~	+
-	~~if(rs != 3){ liqapp_log("liqaccel, cannot read information"); return -2;}~~	+
-	~~int bx=*ax;~~	+
-	~~int by=*ay;~~	+
-	~~int bz=*az;~~	+
-	~~if(ocnt>0)~~	+
-	{	+
-	ax=oax+(bx-oax)0.1;	+
-	ay=oay+(by-oay)0.1;	+
-	az=oaz+(bz-oaz)0.1;	+
-	}	+
-	~~oax=*ax;~~	+
-	~~oay=*ay;~~	+
-	~~oaz=*az;~~	+
-	~~ocnt++;~~	+
-	~~return 0;~~	+
-	}	+
-	~~</source>~~	+
-		+
-	~~[[Category:Development]]~~	+
-	~~[[Category:Fremantle]]~~	+
-	~~[[Category:Hardware]]~~	+
-	~~[[Category:Sensors~~]]	+

amigadave: use

2010-06-14T13:33:50Z

use <source>

← Older revision		Revision as of 13:33, 14 June 2010
Line 72:		Line 72:

	Using the sysfs interface:		Using the sysfs interface:
-	<~~pre~~>	+	<source lang="python">
	def get_rotation():		def get_rotation():
	f = open("/sys/class/i2c-adapter/i2c-3/3-001d/coord", 'r' )		f = open("/sys/class/i2c-adapter/i2c-3/3-001d/coord", 'r' )
Line 78:		Line 78:
	f.close()		f.close()
	return coords		return coords
-	</~~pre~~>	+	</source>

-	And using the D-Bus interface	+	And using the D-Bus interface:
-	<~~pre~~>	+	<source lang="python">
	import dbus		import dbus
	bus = dbus.SystemBus()		bus = dbus.SystemBus()
Line 88:		Line 88:
	'com.nokia.mce.request')		'com.nokia.mce.request')
	orientation , stand , face , x , y , z = accel.get_device_orientation()		orientation , stand , face , x , y , z = accel.get_device_orientation()
-	</~~pre~~>	+	</source>
	x,y,z are the raw accelerometer measurements values, and the first three variables give text information about the device orientation. In particular, the first one informs about the landscape/portrait state.		x,y,z are the raw accelerometer measurements values, and the first three variables give text information about the device orientation. In particular, the first one informs about the landscape/portrait state.

Line 98:		Line 98:
	(GPL code extracted from libliqbase: liqaccel.c)		(GPL code extracted from libliqbase: liqaccel.c)

-	<~~pre~~>	+	<source lang="c">
-		+
	static int ocnt=0;		static int ocnt=0;
	static int oax=0;		static int oax=0;
Line 131:		Line 130:
	return 0;		return 0;
	}		}
-	</~~pre~~>	+	</source>

	[[Category:Development]]		[[Category:Development]]

javiplx: /* Python & D-Bus */

2010-04-20T09:36:14Z

Python & D-Bus

← Older revision		Revision as of 09:36, 20 April 2010
Line 80:		Line 80:
	</pre>		</pre>

		+	And using the D-Bus interface
		+	<pre>
		+	import dbus
		+	bus = dbus.SystemBus()
		+	accel = bus.get_object('com.nokia.mce',
		+	'/com/nokia/mce/request',
		+	'com.nokia.mce.request')
		+	orientation , stand , face , x , y , z = accel.get_device_orientation()
		+	</pre>
		+	x,y,z are the raw accelerometer measurements values, and the first three variables give text information about the device orientation. In particular, the first one informs about the landscape/portrait state.

	== Smoothed C interface ==		== Smoothed C interface ==

onion: Categories

2010-03-26T08:14:10Z

milo: /* Using the data */

2010-02-23T17:47:54Z

Using the data

← Older revision		Revision as of 17:47, 23 February 2010
Line 61:		Line 61:
	== Using the data ==		== Using the data ==

-	The ''X'' and ''Y'' values can be used to calculate<ref>Tom Pycke, ''[http://tom.pycke.be/mav/69/accelerometer-to-attitude Accelerometer to pitch and roll]''</ref> the ~~roll~~ (that is, clockwise rotation) using the ''atan2'' function (note the inverted sign of ''y''):	+	The ''X'' and ''Y'' values can be used to calculate<ref>Tom Pycke, ''[http://tom.pycke.be/mav/69/accelerometer-to-attitude Accelerometer to pitch and roll]''</ref> the pitch (that is, clockwise rotation) using the ''atan2'' function (note the inverted sign of ''y''):

	angle_in_radians = '''atan2'''(''x'', -''y'')		angle_in_radians = '''atan2'''(''x'', -''y'')

-	Similar, ''Y'' and ''Z'' can be used to calculate the ~~pitch~~:	+	Similar, ''Y'' and ''Z'' can be used to calculate the roll:

	angle_in_radians = '''atan2'''(''y'', -''z'')		angle_in_radians = '''atan2'''(''y'', -''z'')

109.108.3.85: /* sysfs */

2010-02-21T13:55:48Z

sysfs

← Older revision		Revision as of 13:55, 21 February 2010
Line 50:		Line 50:
	\|-		\|-
	\| Bottom right corner down (approx.)		\| Bottom right corner down (approx.)
-	\| -~~500~~	+	\| -707
-	\| -~~500~~	+	\| -707
	\| 0		\| 0
	\|}		\|}

amigadave: wikify

2010-02-19T09:26:05Z

wikify

← Older revision		Revision as of 09:26, 19 February 2010
Line 1:		Line 1:
-	[[Fremantle]] provides an accelerometer API. ~~Currently<ref>~~[https://bugs.maemo.org/show_bug.cgi?id=4724 ~~#4724] ''Lack of official documentation on how to use the accelerometer''</ref> there are~~ two interfaces available:	+	[[Open development/Maemo roadmap/Fremantle\|Fremantle]] provides an accelerometer API. There are currently [https://bugs.maemo.org/show_bug.cgi?id=4724 two interfaces available]:
	# D-Bus		# D-Bus
	# sysfs		# sysfs
Line 123:		Line 123:
	</pre>		</pre>

-	~~== References ==~~	+	[[Category:Development]]
-		+	[[Category:Fremantle]]
-	~~<small>~~	+
-	~~<references/>~~	+
-	~~</small>~~	+
-		+
-	[[Category:Development]][[Category:Fremantle]]	+

amigadave: add [[Fremantle[[ link

2010-01-28T16:38:46Z

add [[Fremantle[[ link

← Older revision		Revision as of 16:38, 28 January 2010
Line 1:		Line 1:
-	Fremantle provides an accelerometer API. Currently<ref>[https://bugs.maemo.org/show_bug.cgi?id=4724 #4724] ''Lack of official documentation on how to use the accelerometer''</ref> there are two interfaces available:	+	[[Fremantle]] provides an accelerometer API. Currently<ref>[https://bugs.maemo.org/show_bug.cgi?id=4724 #4724] ''Lack of official documentation on how to use the accelerometer''</ref> there are two interfaces available:
	# D-Bus		# D-Bus
	# sysfs		# sysfs

189.115.169.82: /* sysfs */

2010-01-18T13:04:56Z

sysfs

← Older revision		Revision as of 13:04, 18 January 2010
Line 56:		Line 56:

	These are theoretical values. In real life your mileage will vary.		These are theoretical values. In real life your mileage will vary.
		+
		+	An example can be found at: [http://git.zimmerle.org/?p=inclinometer.git;a=summary]

	== Using the data ==		== Using the data ==

← Older revision		Revision as of 08:14, 26 March 2010
Line 125:		Line 125:
	[[Category:Development]]		[[Category:Development]]
	[[Category:Fremantle]]		[[Category:Fremantle]]
		+	[[Category:Hardware]]
		+	[[Category:Sensors]]