PSoC Torch Height Sensing - Revision history

ChuckH: /* Cypress PSoC4 Pioneer Board for Capacitive Torch Height Sensing */

2014-09-21T22:52:21Z

Cypress PSoC4 Pioneer Board for Capacitive Torch Height Sensing

← Older revision		Revision as of 22:52, 21 September 2014
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	The PSoc4 ("Programmable System on a Chip") is a small ARM microcontroller with flexible peripherals. One of the peripheral functions is Cypress' "CapSense" capacitive touch sensing. A relevant demo project, using the Arduino-form-factor "Pioneer" board is [http://www.element14.com/community/message/76985 here].		The PSoc4 ("Programmable System on a Chip") is a small ARM microcontroller with flexible peripherals. One of the peripheral functions is Cypress' "CapSense" capacitive touch sensing. A relevant demo project, using the Arduino-form-factor "Pioneer" board is [http://www.element14.com/community/message/76985 here].

			Update: there is a smaller Cypress dev board now for only $ 4

	[[Image:ProximityDetection.jpg]]		[[Image:ProximityDetection.jpg]]

ChuckH: /* ChuckH testing */

2014-01-10T15:50:13Z

ChuckH testing

← Older revision		Revision as of 15:50, 10 January 2014
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	== ChuckH testing ==		== ChuckH testing ==
			=== 10 Jan 2014 ===
			Important note on PSoC4 capacitance sensing: must use PRS clock mode to avoid nonlinear "dead spots" in sigma-delta A to D conversion.
	===12 August 2013===		===12 August 2013===
	Make 4-sector ring for testing.		Make 4-sector ring for testing.

ChuckH: /* ChuckH testing */

2013-08-13T04:41:41Z

ChuckH testing

← Older revision		Revision as of 04:41, 13 August 2013
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	== ChuckH testing ==		== ChuckH testing ==
			===12 August 2013===
			Make 4-sector ring for testing.

			[[Image:QuadRing.jpg\|300px]]
	===29 July 2013===		===29 July 2013===
	Current thoughts:		Current thoughts:
	# Coil spring support (see 24-July pics) is nifty for tolerating side impacts, but it swivels too freely about its vertical axis. Maybe it's just too cute and we should use a solid piece of conduit instead.		# Coil spring support (see 24-July pics) is nifty for tolerating side impacts, but it swivels too freely about its vertical axis. Maybe it's just too cute and we should use a solid piece of conduit instead.
	# I am skeptical about the performance of the ring sensor over edges, holes, and ~~aything~~ else that is not a simple uniform plate of metal.		# I am skeptical about the performance of the ring sensor over edges, holes, and anything else that is not a simple uniform plate of metal.
	## Simple minded control would cause torch to dive down when approaching an edge or passing a cutout		## Simple minded control would cause torch to dive down when approaching an edge or passing a cutout
	## Logic could tell z-axis to "hold position" (i.e. stop tracking) if we know that an edge or gap is coming up, but this would require much more sophisticated and brittle CAM programming		## Logic could tell z-axis to "hold position" (i.e. stop tracking) if we know that an edge or gap is coming up, but this would require much more sophisticated and brittle CAM programming

ChuckH: /* 29 July 2013 */

2013-07-29T21:32:23Z

29 July 2013

← Older revision		Revision as of 21:32, 29 July 2013
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	## Logic could tell z-axis to "hold position" (i.e. stop tracking) if we know that an edge or gap is coming up, but this would require much more sophisticated and brittle CAM programming		## Logic could tell z-axis to "hold position" (i.e. stop tracking) if we know that an edge or gap is coming up, but this would require much more sophisticated and brittle CAM programming
	## My preferred solution would be a 4-sector ring, and assuming that at least one sector will be over solid metal. There may still be corner cases missed by a "track Z by the closest sector reading" policy but not many.		## My preferred solution would be a 4-sector ring, and assuming that at least one sector will be over solid metal. There may still be corner cases missed by a "track Z by the closest sector reading" policy but not many.
	## Most commercial cap-sense ICs are set up to handle lots of inputs (i.e. keypads) so this is only a ring-fabrication and wiring issue.		## Most commercial cap-sense ICs are set up to handle lots of inputs (i.e. keypads) so this is only a ring-fabrication and wiring issue. Making the ring out of PC-board material sounds good.

	===27 July 2013===		===27 July 2013===

ChuckH: /* 29 July 2013 */

2013-07-29T21:31:18Z

29 July 2013

← Older revision		Revision as of 21:31, 29 July 2013
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	# I am skeptical about the performance of the ring sensor over edges, holes, and aything else that is not a simple uniform plate of metal.		# I am skeptical about the performance of the ring sensor over edges, holes, and aything else that is not a simple uniform plate of metal.
	## Simple minded control would cause torch to dive down when approaching an edge or passing a cutout		## Simple minded control would cause torch to dive down when approaching an edge or passing a cutout
	## Logic could tell z-axis to "hold position" (i.e. stop tracking) if we know ~~about the~~ edge or gap, but this would require much more sophisticated and brittle CAM programming		## Logic could tell z-axis to "hold position" (i.e. stop tracking) if we know that an edge or gap is coming up, but this would require much more sophisticated and brittle CAM programming
	## My preferred solution would be a 4-sector ring, and assuming that at least one sector will be over solid metal. There may still be corner cases missed by a "track Z by the closest sector reading" policy but not many.		## My preferred solution would be a 4-sector ring, and assuming that at least one sector will be over solid metal. There may still be corner cases missed by a "track Z by the closest sector reading" policy but not many.
	## Most commercial cap-sense ICs are set up to handle lots of inputs (i.e. keypads) so this is only a ring-fabrication and wiring issue.		## Most commercial cap-sense ICs are set up to handle lots of inputs (i.e. keypads) so this is only a ring-fabrication and wiring issue.

	===27 July 2013===		===27 July 2013===
	[[Image:Flatring500_150.png\|thumb\|0.05-in steps .50-.15-.50 in]]		[[Image:Flatring500_150.png\|thumb\|0.05-in steps .50-.15-.50 in]]

ChuckH: /* ChuckH testing */

2013-07-29T21:30:15Z

ChuckH testing

← Older revision		Revision as of 21:30, 29 July 2013
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	== ChuckH testing ==		== ChuckH testing ==

			===29 July 2013===
			Current thoughts:
			# Coil spring support (see 24-July pics) is nifty for tolerating side impacts, but it swivels too freely about its vertical axis. Maybe it's just too cute and we should use a solid piece of conduit instead.
			# I am skeptical about the performance of the ring sensor over edges, holes, and aything else that is not a simple uniform plate of metal.
			## Simple minded control would cause torch to dive down when approaching an edge or passing a cutout
			## Logic could tell z-axis to "hold position" (i.e. stop tracking) if we know about the edge or gap, but this would require much more sophisticated and brittle CAM programming
			## My preferred solution would be a 4-sector ring, and assuming that at least one sector will be over solid metal. There may still be corner cases missed by a "track Z by the closest sector reading" policy but not many.
			## Most commercial cap-sense ICs are set up to handle lots of inputs (i.e. keypads) so this is only a ring-fabrication and wiring issue.
	===27 July 2013===		===27 July 2013===
	[[Image:Flatring500_150.png\|thumb\|0.05-in steps .50-.15-.50 in]]		[[Image:Flatring500_150.png\|thumb\|0.05-in steps .50-.15-.50 in]]

ChuckH: /* 24 July 2013 */

2013-07-27T23:51:04Z

24 July 2013

← Older revision		Revision as of 23:51, 27 July 2013
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	## Wood split clamp provides electrical insulation for ring		## Wood split clamp provides electrical insulation for ring

	[[Image:RingOnSpring.JPG\|~~320px~~]]		[[Image:RingOnSpring.JPG\|160px]] [[Image:ring_on_spring_test.jpg\|480px]]

	===21 July 2013===		===21 July 2013===

ChuckH: /* 27 July 2013 */

2013-07-27T23:47:47Z

27 July 2013

← Older revision		Revision as of 23:47, 27 July 2013
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	===27 July 2013===		===27 July 2013===
			[[Image:Flatring500_150.png\|thumb\|0.05-in steps .50-.15-.50 in]]
	Results from new flat aluminum sensing ring		Results from new flat aluminum sensing ring
	# Signal is large, had to adjust PSoC A to D parameters to avoid overload		# Signal is large, had to adjust PSoC A to D parameters to avoid overload

ChuckH: /* ChuckH testing */

2013-07-27T23:43:04Z

ChuckH testing

← Older revision		Revision as of 23:43, 27 July 2013
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	== ChuckH testing ==		== ChuckH testing ==

			===27 July 2013===

			Results from new flat aluminum sensing ring
			# Signal is large, had to adjust PSoC A to D parameters to avoid overload
			# Easily discriminates .050 inch steps, verified up to 0.5 inch standoff
			# Loss of signal strength at edge of plate: 0.25 inch standoff over solid plate measures the same as 0.10 inch standoff centered over plate edge.

	===24 July 2013===		===24 July 2013===

ChuckH: /* 24 July 2013 */

2013-07-25T05:57:09Z

24 July 2013

← Older revision		Revision as of 05:57, 25 July 2013
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	# Coil spring mount		# Coil spring mount
	## Protects against accidental damage because it bends when hit but springs back to original position		## Protects against accidental damage because it bends when hit but springs back to original position
	## ~~Hollow~~ center ~~provides~~ a grounded secondary shield ~~around coax signal line~~		## Coax signal line runs through hollow center of coil spring, providing a grounded secondary shield
	## Wood split clamp provides electrical insulation for ring		## Wood split clamp provides electrical insulation for ring