Bots-hitechnic-compass - Revision history

Charliep at 21:06, 29 February 2016

2016-02-29T21:06:45Z

← Older revision		Revision as of 21:06, 29 February 2016
Line 2:		Line 2:
	----		----
	== HiTechnic compass ==		== HiTechnic compass ==
	Copy the [http://cs.earlham.edu/~~~leemasa~~/~~robotics~~/hicompass.py hicompass library] into the directory of the rest of your NXT libraries		Copy the [http://cluster.earlham.edu/~charliep/courses/cs382/hicompass.py hicompass library] into the directory of the rest of your NXT libraries

	* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]		* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]

Leemasa: /* Functions */

2010-04-04T19:55:12Z

Functions

← Older revision		Revision as of 19:55, 4 April 2010
Line 12:		Line 12:
	*CompassSensor(bot, port) - declares a HiTechnic compass object		*CompassSensor(bot, port) - declares a HiTechnic compass object
	*get_manufacturer() - returns the eight-character string in the "manufacturer" block of the device (should be HiTechnc)		*get_manufacturer() - returns the eight-character string in the "manufacturer" block of the device (should be HiTechnc)
	*get_type() - returns the eight-character string in the "Type" block of the device (should be Compass)		*get_type() - returns the eight-character string in the "Type" block of the device (should be "Compass ")
			** Note the extra space after Compass
	*get_sample(tries=5) - returns the heading measurement of the sensor in degrees clockwise from due North.		*get_sample(tries=5) - returns the heading measurement of the sensor in degrees clockwise from due North.
	**Although bus errors wit the hicompass are relatively rare, get_sample() automatically tries again if it fails to get a heading.		**Although bus errors wit the hicompass are relatively rare, get_sample() automatically tries again if it fails to get a heading.

Leemasa: /* HiTechnic compass */

2010-04-04T19:21:01Z

HiTechnic compass

← Older revision		Revision as of 19:21, 4 April 2010
Line 2:		Line 2:
	----		----
	== HiTechnic compass ==		== HiTechnic compass ==
	Copy the [http://cs.earlham.edu/~leemasa/robotics/hicompass.py hicompass library] into your NXT ~~directory~~		Copy the [http://cs.earlham.edu/~leemasa/robotics/hicompass.py hicompass library] into the directory of the rest of your NXT libraries

	* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]		* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]

Leemasa: /* HiTechnic compass */

2010-04-04T19:20:26Z

HiTechnic compass

← Older revision		Revision as of 19:20, 4 April 2010
Line 12:		Line 12:
	*CompassSensor(bot, port) - declares a HiTechnic compass object		*CompassSensor(bot, port) - declares a HiTechnic compass object
	*get_manufacturer() - returns the eight-character string in the "manufacturer" block of the device (should be HiTechnc)		*get_manufacturer() - returns the eight-character string in the "manufacturer" block of the device (should be HiTechnc)
			*get_type() - returns the eight-character string in the "Type" block of the device (should be Compass)
	*get_sample(tries=5) - returns the heading measurement of the sensor in degrees clockwise from due North.		*get_sample(tries=5) - returns the heading measurement of the sensor in degrees clockwise from due North.
	**Although bus errors wit the hicompass are relatively rare, get_sample() automatically tries again if it fails to get a heading.		**Although bus errors wit the hicompass are relatively rare, get_sample() automatically tries again if it fails to get a heading.
Line 24:		Line 25:
	=== Examples ===		=== Examples ===
	Plug your compass into port four and place the following code somewhere in a program that already works with your robot		Plug your compass into port four and place the following code somewhere in a program that already works with your robot
	import hicompass		import nxt.hicompass
	bot = (whatever variable you use to refer to your bot)		bot = (whatever variable you use to refer to your bot)
	compass = hicompass.CompassSensor(bot,PORT_4)		compass = hicompass.CompassSensor(bot,PORT_4)

Leemasa: /* Calibrating the Compass */

2010-03-25T13:31:24Z

Calibrating the Compass

← Older revision		Revision as of 13:31, 25 March 2010
Line 39:		Line 39:
	#*The size and precision of the circle is unimportant as long as the robot can make a full revolution		#*The size and precision of the circle is unimportant as long as the robot can make a full revolution
	#Set your compass sensor to calibrate mode and instruct your robot to drive in a circle		#Set your compass sensor to calibrate mode and instruct your robot to drive in a circle
	#*~~The~~ robot ~~should~~ make between one and a half and two revolutions in about twenty seconds and stop		#*Your program should tell the robot to make between one and a half and two revolutions in about twenty seconds and stop
	#Be sure to set your compass sensor back to measure mode when you are done!		#Be sure to set your compass sensor back to measure mode when you are done!

Leemasa: /* Notes */

2010-03-09T01:15:26Z

Notes

← Older revision		Revision as of 01:15, 9 March 2010
Line 47:		Line 47:
	*Make sure the sensor is steady. The more it bounces around the less accurate your readings will be		*Make sure the sensor is steady. The more it bounces around the less accurate your readings will be
	*Keep the sensor at least four inches from your NXT brick and six from your motors. They generate magnetic fields that will result in inaccurate readings.		*Keep the sensor at least four inches from your NXT brick and six from your motors. They generate magnetic fields that will result in inaccurate readings.
			*Writing to the sensor (changing modes) takes a finite amount of time. Writing multiple times in succession or writing and immediately trying to get a sample is likely to return a bus error.
			**Multiple consecutive reads are not an issue.

Leemasa: /* Functions */

2010-03-09T01:12:49Z

Functions

← Older revision		Revision as of 01:12, 9 March 2010
Line 12:		Line 12:
	*CompassSensor(bot, port) - declares a HiTechnic compass object		*CompassSensor(bot, port) - declares a HiTechnic compass object
	*get_manufacturer() - returns the eight-character string in the "manufacturer" block of the device (should be HiTechnc)		*get_manufacturer() - returns the eight-character string in the "manufacturer" block of the device (should be HiTechnc)
	*get_sample() - returns the heading measurement of the sensor in degrees clockwise from due North.		*get_sample(tries=5) - returns the heading measurement of the sensor in degrees clockwise from due North.
	**Although bus errors wit the hicompass are relatively rare, get_sample() automatically tries again if it fails to get a heading.		**Although bus errors wit the hicompass are relatively rare, get_sample() automatically tries again if it fails to get a heading.
			***You may specify the number of tries before it fails as the first argument, but the default is five
			*get_relative_heading(target=0) - returns the heading relative to target. Returns a value between -180 and 180.
			*is_in_range(min,max) - returns whether the compass heading is within the specified range.
			**To get a range of the opposite side of the circle, reverse max and min
	*calibrate_mode() - sets the compass to calibrate mode to correct for magnetic interference.		*calibrate_mode() - sets the compass to calibrate mode to correct for magnetic interference.
	**see Calibrating the Compass below		**see Calibrating the Compass below
	*measure_mode() - sets the compass to measure mode. The compass is in this mode by default		*measure_mode() - sets the compass to measure mode. The compass is in this mode by default

Leemasa: /* HiTechnic compass */

2010-03-08T15:38:26Z

HiTechnic compass

← Older revision		Revision as of 15:38, 8 March 2010
Line 2:		Line 2:
	----		----
	== HiTechnic compass ==		== HiTechnic compass ==
	[http://cs.earlham.edu/~leemasa/robotics/hicompass.py hicompass library]		Copy the [http://cs.earlham.edu/~leemasa/robotics/hicompass.py hicompass library] into your NXT directory

	* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]		* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]
Line 20:		Line 20:
	=== Examples ===		=== Examples ===
	Plug your compass into port four and place the following code somewhere in a program that already works with your robot		Plug your compass into port four and place the following code somewhere in a program that already works with your robot
			import hicompass
	bot = (whatever variable you use to refer to your bot)		bot = (whatever variable you use to refer to your bot)
	compass = hicompass.CompassSensor(bot,PORT_4)		compass = hicompass.CompassSensor(bot,PORT_4)

Leemasa: /* HiTechnic compass */

2010-03-08T15:37:19Z

HiTechnic compass

← Older revision		Revision as of 15:37, 8 March 2010
Line 2:		Line 2:
	----		----
	== HiTechnic compass ==		== HiTechnic compass ==
	[http://cs.earlham.edu/~leemasa/robotics/hicompass.py hicompass~~.py~~]		[http://cs.earlham.edu/~leemasa/robotics/hicompass.py hicompass library]

	* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]		* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]

Leemasa: /* HiTechnic compass */

2010-03-08T15:36:39Z

HiTechnic compass

← Older revision		Revision as of 15:36, 8 March 2010
Line 1:		Line 1:
	Back to [https://wiki.cs.earlham.edu/index.php/Robotics-2010 Robotics Main Page]		Back to [https://wiki.cs.earlham.edu/index.php/Robotics-2010 Robotics Main Page]
	----		----
	=== HiTechnic compass ===		== HiTechnic compass ==
			[http://cs.earlham.edu/~leemasa/robotics/hicompass.py hicompass.py]

	* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]		* Detailed design and usage information for the HiTechnic [http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NMC1034 compass sensor]
	* ~~Because~~ of the ~~way~~ the ~~registers are mapped you can use~~ the ~~<code>UltrasonicSensor</code> class to work with this compass~~. ~~The value returned by <code>get_sample()</code> is 1/2~~ the ~~actual~~ heading ~~in degrees, that~~ is ~~you multiply the returned value by 2 to calculate the heading.~~		** Note: The description of how heading is stored in the sensor is incorrect. 0x44 points to the low byte and 0x45 points to the high bit. In other words, the formula for getting heading is (0x44) + 255*(0x45)
	* Calibration is rarely necessary and shouldn't be an issue for us in the near-~~term.~~
	* ~~Example code:~~
	~~#!/usr/bin/env python~~		=== Functions ===
	~~# This example uses~~ the "~~plain~~" ~~UltraSonic~~ (~~i.e. digital~~) ~~sensor interface~~		Expect more functions in the near future
	~~# with~~ the ~~HiTechnic compass~~ sensor. ~~The compass_heading~~() ~~function~~		*CompassSensor(bot, port) - declares a HiTechnic compass object
	~~# attempts~~ to ~~do the conversion~~ to ~~degrees (but omits~~ the ~~adder register~~		*get_manufacturer() - returns the eight-character string in the "manufacturer" block of the device (should be HiTechnc)
	~~# as documented by HiTechnic~~).		*get_sample() - returns the heading measurement of the sensor in degrees clockwise from due North.
			**Although bus errors wit the hicompass are relatively rare, get_sample() automatically tries again if it fails to get a heading.
	~~import time~~		*calibrate_mode() - sets the compass to calibrate mode to correct for magnetic interference.
	~~import nxt.locator~~		**see Calibrating the Compass below
	from nxt.sensor import *		*measure_mode() - sets the compass to measure mode. The compass is in this mode by default

	~~def id_nxt~~(b):		=== Examples ===
	~~name, host, signal_strength, user_flash~~ = b.~~get_device_info~~()		Plug your compass into port four and place the following code somewhere in a program that already works with your robot
	print ~~'NXT brick name: %s' % name~~
	~~print 'Host address: %s' % host~~		bot = (whatever variable you use to refer to your bot)
	~~print 'Bluetooth signal strength: %s' % signal_strength~~		compass = hicompass.CompassSensor(bot,PORT_4)
	~~print 'Free user flash: %s' % user_flash~~		print compass.get_manufacturer()
			heading = compass.get_sample()
	~~def compass_heading~~(~~b, p~~):		while heading > 10:
	~~# Because of limitations in the UltraSonic interface it returns 1/2 the~~		heading = compass.get_sample()
	~~# actual~~ heading.		print 'Heading: ', heading
	~~return UltrasonicSensor(b, p)~~.get_sample() * 2
			This will tell the sensor to collect headings until it is within ten degrees East of due North.
	~~print 'Looking for brick 1 ...'~~
	~~sock~~ = ~~nxt~~.~~locator.find_one_brick~~(~~host='00:16:53:06:ED:B8', name='NXT'~~)		=== Calibrating the Compass ===
			#Assemble a mobile robot that can drive in a circle
	~~if sock:~~		#*The size and precision of the circle is unimportant as long as the robot can make a full revolution
	print '~~Found brick 1'~~		#Set your compass sensor to calibrate mode and instruct your robot to drive in a circle
	~~else~~:		#*The robot should make between one and a half and two revolutions in about twenty seconds and stop
	~~print~~ '~~Timed-out~~, ~~no NXT bricks found, exiting'~~		#Be sure to set your compass sensor back to measure mode when you are done!
	~~exit~~
			=== Notes ===
	~~if sock:~~		The compass sensor is a very sensitive device. Here are some tips to make sure you get accurate readings
	~~print 'Connecting to~~ the ~~brick ...'~~		*Keep the sensor level
	~~bot~~ = ~~sock.connect()~~		*Make sure the sensor is steady. The more it bounces around the less accurate your readings will be
			*Keep the sensor at least four inches from your NXT brick and six from your motors. They generate magnetic fields that will result in inaccurate readings.
	~~if bot:~~
	~~print 'Connected~~ to ~~the brick'~~
	~~else:~~
	~~print 'Timed-out connecting~~ to ~~brick 1, exiting'~~
	~~exit~~

	~~if bot:~~
	~~id_nxt(bot)~~

	~~while 1:~~
	~~try:~~
	~~print 'Compass heading: ', compass_heading(bot, PORT_4)~~
	~~time~~.~~sleep(1)~~
	~~continue~~
	~~except:~~
	~~time~~.~~sleep(1)~~
	~~continue~~