Vibratory Clock - Revision history

BrianLesperance: /* Design Description */

2008-03-21T08:08:34Z

Design Description

← Older revision		Revision as of 03:08, 21 March 2008
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	===Design Description===		===Design Description===

	The PIC sends a digitized version of three sine waves to the DAC for conversion. The signal then passes through a LPF filter before going to a power amplifier and finally the speakers themselves, which vibrate the surface plate.		The PIC sends a digitized version of three sine waves to the [[PIC18F4520:_Serial_Digital-to-Analog_Conversion\|DAC]] for conversion. The signal then passes through a LPF filter before going to a power amplifier and finally the speakers themselves, which vibrate the surface plate.

	<b>Digital-to-Analog Converter</b>		<b>Digital-to-Analog Converter</b>

BrianLesperance: /* Design Description */

2008-03-21T08:04:28Z

Design Description

← Older revision		Revision as of 03:04, 21 March 2008
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	<b>Digital-to-Analog Converter</b>		<b>Digital-to-Analog Converter</b>

	The PIC would step through the sampled sine wave, stored in program memory, and send the values to the DAC. Since we need 3 individual sine waves, we selected the [http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1251 Maxim MAX520], a quad DAC IC. It uses I<sup>2</sup>C with which our PIC easily interfaces and a simple message protocol.		The PIC would step through the sampled sine wave, stored in program memory, and send the values to the DAC. Since we need 3 individual sine waves, we selected the [http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1251 Maxim MAX520], a quad DAC IC. It uses I<sup>2</sup>C with which our PIC easily interfaces and a simple message protocol. With I<sup>2</sup>C, normally the protocol describes a start and stop bit. In between that there are a hardware address byte and subsequent message bytes. Since there are 3 hardware address pins on this IC up to 8 (2<sup>3</sup>) can be used on a single I<sup>2</sup>C bus. After the address byte, the first message byte indicates which converter in the quad DAC that the following message is for (software address). The second message byte is the 8-bit value for the previously selected converter. Several converters (in the same DAC IC) can be spoken to within the same start and stop bits by simply repeating the software address message and the converter value message for the different converters in a single DAC IC.

	<b>Design Evolution</b>		<b>Design Evolution</b>

BrianLesperance: /* Software Design */

2008-03-21T07:34:57Z

Software Design

← Older revision		Revision as of 02:34, 21 March 2008
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	[[media:Team22_code.c\|Full Code]]		[[media:Team22_code.c\|Full Code]]

	~~===Code~~ Description~~===~~		<b>Description</b>

	The PIC has a sine wave stored in program memory in the form of a look-up table (LUT~~) (really not necessary but larger projects might need this~~). The main code simply steps through the LUT and outputs that value to the DAC. This will create a "stepping" sine wave, which get smoothed out by the passive LPF before the signal is sent to the power amplifier. There is a interrupt service routine that occurs every .825 seconds to alternate between two orthogonal line sinks, to create a node to which a time piece will go. Additionally, every 10 seconds within the interrupt, the time is changed in that the position of the node moves to the next hour. Our code has the hour positions hard coded and simply steps through all of them. More positions can easily be added for better resolution, which would be useful in an hour hand.		The PIC has a sine wave stored in program memory in the form of a look-up table (LUT). The main code simply steps through the LUT and outputs that value to the DAC. This will create a "stepping" sine wave, which get smoothed out by the passive LPF before the signal is sent to the power amplifier. There is an interrupt service routine that occurs every .825 seconds to alternate between two orthogonal line sinks, to create a node to which a time piece will go. Additionally, every 10 seconds within the interrupt, the time is changed in that the position of the node moves to the next hour. Our code has the hour positions hard coded and simply steps through all of them. More positions can easily be added for better resolution, which would be useful in an hour hand.

	===Flowchart===

	==Results==		==Results==

JenniferBreger: /* Results */

2008-03-20T22:12:54Z

Results

← Older revision		Revision as of 17:12, 20 March 2008
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	==Results==		==Results==
	[[Image:VibratoryClock.jpg\|right\|Bird's-eye view of the Vibratory Clock\|thumb\|~~300px~~]]		[[Image:VibratoryClock.jpg\|right\|Bird's-eye view of the Vibratory Clock\|thumb\|350px]]

	We were able to get our project working so that the plate moves an object placed anywhere on the plate to the correct time and then moves the objects around the clock face, acting as the hour "hand" of a clock. However, we increased the speed so that it takes about 2 minutes for objects placed on the clock to move around so that it is easy to demonstrate. Check out the working Vibratory Clock [http://www.youtube.com/watch?v=KhgTNCfdwZw here].		We were able to get our project working so that the plate moves an object placed anywhere on the plate to the correct time and then moves the objects around the clock face, acting as the hour "hand" of a clock. However, we increased the speed so that it takes about 2 minutes for objects placed on the clock to move around so that it is easy to demonstrate. Check out the working Vibratory Clock [http://www.youtube.com/watch?v=KhgTNCfdwZw here].

JenniferBreger: /* Mechanical Design */

2008-03-20T22:12:23Z

Mechanical Design

← Older revision		Revision as of 17:12, 20 March 2008
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	*adjustable legs: 3 rods: 3/8"-16; 4" long; 6 nuts total		*adjustable legs: 3 rods: 3/8"-16; 4" long; 6 nuts total

	[[Image:speaker_supports.jpg\|right\|Pylons connecting the speakers to the platform\|thumb\|~~200px~~]]		[[Image:speaker_supports.jpg\|right\|Pylons connecting the speakers to the platform\|thumb\|300px]]

	''Speakers:''		''Speakers:''

JenniferBreger: /* Theory */

2008-03-20T22:07:33Z

Theory

← Older revision		Revision as of 17:07, 20 March 2008
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	===Theory===		===Theory===
	[[Image:theory.jpg\|right\|Diagram of theory\|thumb\|~~250px~~]]		[[Image:theory.jpg\|right\|Diagram of theory\|thumb\|300px]]

	Through his [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm research], Professor Lynch discovered that when a platform is rotated about a line beneath it, orthogonal sinks and nodes can be created. These can be adjusted by placing speaker vibrations at different amplitudes and phases. This concept can be applied to create a node at any point on the platform, but is most easily explained when two speakers are placed at equal amplitudes and opposite phases, creating a sink between the two speakers. As illustrated in the diagram, a line sink is created along Line 1 by placing Speaker B and Speaker C at equal amplitude but opposite phases, while holding Speaker A is off. If several small objects were placed on the plate at this point, all the objects would converge to the central line of the plate. A second line sink, orthogonal to the first, is created along Line 2 by once again placing Speakers B and C at equal amplitudes but this time in phase with each other. Speaker A is placed at a small amplitude and out of phase with speakers B and C, which moves the line sink slightly away from the edge of the plate.		Through his [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm research], Professor Lynch discovered that when a platform is rotated about a line beneath it, orthogonal sinks and nodes can be created. These can be adjusted by placing speaker vibrations at different amplitudes and phases. This concept can be applied to create a node at any point on the platform, but is most easily explained when two speakers are placed at equal amplitudes and opposite phases, creating a sink between the two speakers. As illustrated in the diagram, a line sink is created along Line 1 by placing Speaker B and Speaker C at equal amplitude but opposite phases, while holding Speaker A is off. If several small objects were placed on the plate at this point, all the objects would converge to the central line of the plate. A second line sink, orthogonal to the first, is created along Line 2 by once again placing Speakers B and C at equal amplitudes but this time in phase with each other. Speaker A is placed at a small amplitude and out of phase with speakers B and C, which moves the line sink slightly away from the edge of the plate.

JenniferBreger: /* Theory */

2008-03-20T22:07:13Z

Theory

← Older revision		Revision as of 17:07, 20 March 2008
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	===Theory===		===Theory===
	[[Image:theory.jpg\|right\|Diagram of theory\|thumb\|~~200px~~]]		[[Image:theory.jpg\|right\|Diagram of theory\|thumb\|250px]]

	Through his [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm research], Professor Lynch discovered that when a platform is rotated about a line beneath it, orthogonal sinks and nodes can be created. These can be adjusted by placing speaker vibrations at different amplitudes and phases. This concept can be applied to create a node at any point on the platform, but is most easily explained when two speakers are placed at equal amplitudes and opposite phases, creating a sink between the two speakers. As illustrated in the diagram, a line sink is created along Line 1 by placing Speaker B and Speaker C at equal amplitude but opposite phases, while holding Speaker A is off. If several small objects were placed on the plate at this point, all the objects would converge to the central line of the plate. A second line sink, orthogonal to the first, is created along Line 2 by once again placing Speakers B and C at equal amplitudes but this time in phase with each other. Speaker A is placed at a small amplitude and out of phase with speakers B and C, which moves the line sink slightly away from the edge of the plate.		Through his [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm research], Professor Lynch discovered that when a platform is rotated about a line beneath it, orthogonal sinks and nodes can be created. These can be adjusted by placing speaker vibrations at different amplitudes and phases. This concept can be applied to create a node at any point on the platform, but is most easily explained when two speakers are placed at equal amplitudes and opposite phases, creating a sink between the two speakers. As illustrated in the diagram, a line sink is created along Line 1 by placing Speaker B and Speaker C at equal amplitude but opposite phases, while holding Speaker A is off. If several small objects were placed on the plate at this point, all the objects would converge to the central line of the plate. A second line sink, orthogonal to the first, is created along Line 2 by once again placing Speakers B and C at equal amplitudes but this time in phase with each other. Speaker A is placed at a small amplitude and out of phase with speakers B and C, which moves the line sink slightly away from the edge of the plate.

JenniferBreger at 22:04, 20 March 2008

2008-03-20T22:04:53Z

← Older revision		Revision as of 17:04, 20 March 2008
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	[[Image:theory.jpg\|right\|Diagram of theory\|thumb\|200px]]		[[Image:theory.jpg\|right\|Diagram of theory\|thumb\|200px]]

	Through his [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm research], Professor Lynch discovered that when a platform is rotated about a line ~~placed~~ beneath it, orthogonal sinks ~~create~~ nodes ~~which~~ can be adjusted by placing speaker vibrations at different amplitudes and phases. This concept can be applied to create a node at any point on the platform but is most easily explained when two speakers are placed at equal amplitudes and opposite phases ~~to place~~ a sink between two speakers. As illustrated in the diagram a sink is created along Line 1 by placing Speaker B and Speaker C at equal amplitude but opposite ~~phase~~ while holding Speaker A ~~steady~~. A second sink orthogonal to the first is created along Line 2 by once again placing Speakers B and C at equal ~~amplitude~~ but this time in phase with each other. Speaker A ~~remains~~ ~~stationary~~.		Through his [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm research], Professor Lynch discovered that when a platform is rotated about a line beneath it, orthogonal sinks and nodes can be created. These can be adjusted by placing speaker vibrations at different amplitudes and phases. This concept can be applied to create a node at any point on the platform, but is most easily explained when two speakers are placed at equal amplitudes and opposite phases, creating a sink between the two speakers. As illustrated in the diagram, a line sink is created along Line 1 by placing Speaker B and Speaker C at equal amplitude but opposite phases, while holding Speaker A is off. If several small objects were placed on the plate at this point, all the objects would converge to the central line of the plate. A second line sink, orthogonal to the first, is created along Line 2 by once again placing Speakers B and C at equal amplitudes but this time in phase with each other. Speaker A is placed at a small amplitude and out of phase with speakers B and C, which moves the line sink slightly away from the edge of the plate.

	Lines 1 and 2 in the example ~~can be used to~~ create a node at 12 o'clock by alternating between the radial (Line 1) and orthogonal (Line 2) phases~~. In the radial phase, we created a sink along the diameter of the plate between the two speakers that were not along the line through~~ 12 o'clock ~~and~~ 6 ~~o'clock,~~ ~~namely~~ ~~speakers B and C~~. If ~~several~~ ~~small objects were placed on~~ the ~~plate~~ at ~~this point,~~ all the ~~objects~~ ~~would~~ ~~converge~~ to the ~~central~~ ~~line of the plate~~. ~~Next, in~~ order to create the ~~orthogonal sink that would create a node~~ at ~~12 o'clock, we placed speakers B and C in phase and at equal amplitude. However, in order to counteract~~ the ~~forces~~ ~~from speakers B and C~~, we ~~put~~ ~~speaker~~ ~~A (~~the ~~speaker~~ at 12 ~~o'clock)~~ at a ~~weak~~ ~~amplitude~~ ~~and~~ ~~180~~ ~~degrees~~ ~~out~~ ~~of phase with speakers B and C in the orthogonal~~ ~~phase~~.		Lines 1 and 2 in the example create a node at 12 o'clock by alternating between the radial (Line 1) and orthogonal (Line 2) phases (12 o'clock is located above Speaker A). This concept was the used to create all of the even number nodes on the clock face. In order to create the nodes at the odd numbers, we slightly changed the amplitudes of the speakers at the previous time until the correct placement was found.

	This concept was the used to create all of the even number nodes on the clock face. In order to create the nodes at the odd numbers, we slightly changed the amplitudes of the speakers at the previous time until the correct placement was found.

	Although theoretically our design should have allowed us to program the clock using symmetry, due to slight imperfections in the design and in the electrical components, we had to use some trial and error methods to place the nodes correctly. Nonetheless, the theory allowed us to create nodes almost exactly where we wanted them to be.		Although theoretically our design should have allowed us to program the clock using symmetry, due to slight imperfections in the design and in the electrical components, we had to use some trial and error methods to place the nodes correctly. Nonetheless, the theory allowed us to create nodes almost exactly where we wanted them to be.
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	===Achievements===		===Achievements===

	*<b>Independent Speaker Control</b> — each speaker was able to ~~operate~~ entirely independently of the other two in terms of amplitude and phase.		*<b>Independent Speaker Control</b> — each speaker was able to be controlled entirely independently of the other two in terms of amplitude and phase.
	*<b>Line Sinks</b> — objects placed at any point on the platform moved to a point on a single line.		*<b>Line Sinks</b> — objects placed at any point on the platform moved to a point on a single line.
	*<b>Nodes</b> — two line sinks were created to move an object at any point on the platform to a single specified point elsewhere on the platform.		*<b>Nodes</b> — two line sinks were created to move an object at any point on the platform to a single specified point elsewhere on the platform.

DanielPinkawa: /* Theory */

2008-03-20T20:12:26Z

Theory

← Older revision		Revision as of 15:12, 20 March 2008
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	Through his [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm research], Professor Lynch discovered that when a platform is rotated about a line placed beneath it, orthogonal sinks create nodes which can be adjusted by placing speaker vibrations at different amplitudes and phases. This concept can be applied to create a node at any point on the platform but is most easily explained when two speakers are placed at equal amplitudes and opposite phases to place a sink between two speakers. As illustrated in the diagram a sink is created along Line 1 by placing Speaker B and Speaker C at equal amplitude but opposite phase while holding Speaker A steady. A second sink orthogonal to the first is created along Line 2 by once again placing Speakers B and C at equal amplitude but this time in phase with each other. Speaker A remains stationary.		Through his [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm research], Professor Lynch discovered that when a platform is rotated about a line placed beneath it, orthogonal sinks create nodes which can be adjusted by placing speaker vibrations at different amplitudes and phases. This concept can be applied to create a node at any point on the platform but is most easily explained when two speakers are placed at equal amplitudes and opposite phases to place a sink between two speakers. As illustrated in the diagram a sink is created along Line 1 by placing Speaker B and Speaker C at equal amplitude but opposite phase while holding Speaker A steady. A second sink orthogonal to the first is created along Line 2 by once again placing Speakers B and C at equal amplitude but this time in phase with each other. Speaker A remains stationary.

	Lines 1 and 2 in the example can be used to create a node at 12 o'clock by alternating between the radial (Line 1) and orthogonal (Line 2)phases. In the radial phase, we created a sink along the diameter of the plate between the two speakers that were not along the line through 12 o'clock and 6 o'clock, namely speakers B and C. If several small objects were placed on the plate at this point, all the objects would converge to the central line of the plate. Next, in order to create the orthogonal sink that would create a node at 12 o'clock, we placed speakers B and C in phase and at equal amplitude. However, in order to counteract the forces from speakers B and C, we put speaker A (the speaker at 12 o'clock) at a weak amplitude and 180 degrees out of phase with speakers B and C in the orthogonal phase.		Lines 1 and 2 in the example can be used to create a node at 12 o'clock by alternating between the radial (Line 1) and orthogonal (Line 2) phases. In the radial phase, we created a sink along the diameter of the plate between the two speakers that were not along the line through 12 o'clock and 6 o'clock, namely speakers B and C. If several small objects were placed on the plate at this point, all the objects would converge to the central line of the plate. Next, in order to create the orthogonal sink that would create a node at 12 o'clock, we placed speakers B and C in phase and at equal amplitude. However, in order to counteract the forces from speakers B and C, we put speaker A (the speaker at 12 o'clock) at a weak amplitude and 180 degrees out of phase with speakers B and C in the orthogonal phase.

	This concept was the used to create all of the even number nodes on the clock face. In order to create the nodes at the odd numbers, we slightly changed the amplitudes of the speakers at the previous time until the correct placement was found.		This concept was the used to create all of the even number nodes on the clock face. In order to create the nodes at the odd numbers, we slightly changed the amplitudes of the speakers at the previous time until the correct placement was found.

DanielPinkawa: /* Mechanical Design */

2008-03-20T18:56:46Z

Mechanical Design

← Older revision		Revision as of 13:56, 20 March 2008
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	*adjustable legs: 3 rods: 3/8"-16; 4" long; 6 nuts total		*adjustable legs: 3 rods: 3/8"-16; 4" long; 6 nuts total

	[[Image:speaker_supports.jpg\|right\|thumb\|200px]]		[[Image:speaker_supports.jpg\|right\|Pylons connecting the speakers to the platform\|thumb\|200px]]

	''Speakers:''		''Speakers:''