ChepkwonyChatterjee - Revision history

imported>Psych2012: /* PCB Layout */

2012-06-16T19:32:41Z

PCB Layout

← Older revision		Revision as of 19:32, 16 June 2012
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	[[File:Final_Layout.JPG\|center\|thumb\|PCB Layout]]		[[File:Final_Layout.JPG\|center\|thumb\|PCB Layout]]
			[[File:Final.jpg\|center\|thumb\|Assembled circuit board]]

	== Results ==		== Results ==

imported>Psych2012: /* System Optics (Future work) */

2012-06-09T16:49:50Z

System Optics (Future work)

← Older revision		Revision as of 16:49, 9 June 2012
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	== System Optics ''(Future work)'' ==		== System Optics ''(Future work)'' ==
	The electronic circuitry design and assembly has been completed, however the design and integration of the optics of the system is still pending. This ~~component~~ is an interesting challenge. The requirement is a system that is capable of transporting the light from the assembly to a remote location (this will likely be to an fMRI machine).		The electronic circuitry design and assembly has been completed, however the design and integration of the optics of the system is still pending. This is an interesting challenge. The requirement is a system that is capable of transporting the light from the assembly to a remote location (this will likely be to an fMRI machine).

	An idea ~~could be~~ the use of a bundle of Optical fibers packed together and sheathed in ~~some~~ a plastic tube coating. This would form a reliable ~~but~~ flexible transportation medium. ~~The advantage here would be~~ that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:		An idea is the use of a bundle of Optical fibers packed together and sheathed in a plastic tube coating. This would form a reliable and flexible transportation medium. A feature of this design is that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:
	[[File:Center-surround.jpg\|center\|thumb\|border\|'''Sample''' fiber bundle center surround pattern]]		[[File:Center-surround.jpg\|center\|thumb\|border\|'''Sample''' fiber bundle center surround pattern]]

imported>Psych2012: /* System Optics */

2012-06-09T16:33:40Z

System Optics

← Older revision		Revision as of 16:33, 9 June 2012
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	[[File:Gamma_Resp.png\|center\|thumb\|Gamma Response]]		[[File:Gamma_Resp.png\|center\|thumb\|Gamma Response]]

	== System Optics ==		== System Optics ''(Future work)'' ==
	The electronic circuitry design and assembly has been completed, however the design and integration of the optics of the system is still pending. This component is an interesting challenge. The requirement is a system that is capable of transporting the light from the assembly to a remote location (this will likely be to an fMRI machine).		The electronic circuitry design and assembly has been completed, however the design and integration of the optics of the system is still pending. This component is an interesting challenge. The requirement is a system that is capable of transporting the light from the assembly to a remote location (this will likely be to an fMRI machine).

imported>Psych2012: /* System Optics */

2012-06-09T16:31:04Z

System Optics

← Older revision		Revision as of 16:31, 9 June 2012
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	An idea could be the use of a bundle of Optical fibers packed together and sheathed in some a plastic tube coating. This would form a reliable but flexible transportation medium. The advantage here would be that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:		An idea could be the use of a bundle of Optical fibers packed together and sheathed in some a plastic tube coating. This would form a reliable but flexible transportation medium. The advantage here would be that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:
	[[File:Center-surround.jpg\|center\|thumb\|border\|Sample center surround pattern ~~that might be considered~~]]		[[File:Center-surround.jpg\|center\|thumb\|border\|'''Sample''' fiber bundle center surround pattern]]

	== Conclusions ==		== Conclusions ==

imported>Psych2012 at 16:30, 9 June 2012

2012-06-09T16:30:18Z

← Older revision		Revision as of 16:30, 9 June 2012
Line 165:		Line 165:

	An idea could be the use of a bundle of Optical fibers packed together and sheathed in some a plastic tube coating. This would form a reliable but flexible transportation medium. The advantage here would be that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:		An idea could be the use of a bundle of Optical fibers packed together and sheathed in some a plastic tube coating. This would form a reliable but flexible transportation medium. The advantage here would be that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:
	[[File:Center-surround.jpg\|center\|thumb Sample center surround pattern that might be considered]]		[[File:Center-surround.jpg\|center\|thumb\|border\|Sample center surround pattern that might be considered]]

	== Conclusions ==		== Conclusions ==

imported>Psych2012: /* System Optics */

2012-06-09T16:29:27Z

System Optics

← Older revision		Revision as of 16:29, 9 June 2012
Line 165:		Line 165:

	An idea could be the use of a bundle of Optical fibers packed together and sheathed in some a plastic tube coating. This would form a reliable but flexible transportation medium. The advantage here would be that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:		An idea could be the use of a bundle of Optical fibers packed together and sheathed in some a plastic tube coating. This would form a reliable but flexible transportation medium. The advantage here would be that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:
	[[File:Center-surround.jpg\|center\|thumb]]		[[File:Center-surround.jpg\|center\|thumb Sample center surround pattern that might be considered]]

	== Conclusions ==		== Conclusions ==

imported>Psych2012: /* System Optics */

2012-06-09T16:28:58Z

System Optics

← Older revision		Revision as of 16:28, 9 June 2012
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	The electronic circuitry design and assembly has been completed, however the design and integration of the optics of the system is still pending. This component is an interesting challenge. The requirement is a system that is capable of transporting the light from the assembly to a remote location (this will likely be to an fMRI machine).		The electronic circuitry design and assembly has been completed, however the design and integration of the optics of the system is still pending. This component is an interesting challenge. The requirement is a system that is capable of transporting the light from the assembly to a remote location (this will likely be to an fMRI machine).

	An idea could be the use of a bundle of Optical fibers packed together and sheathed in some a plastic tube coating. This would form a reliable but flexible transportation medium.		An idea could be the use of a bundle of Optical fibers packed together and sheathed in some a plastic tube coating. This would form a reliable but flexible transportation medium. The advantage here would be that bundles from the distinct 7 channel assemblies could be taken and combined in any pattern within the sheath for final delivery. A sample of something that might be possible to do is:
			[[File:Center-surround.jpg\|center\|thumb]]
	~~This is an open problem so any help or feedback would help~~.

	== Conclusions ==		== Conclusions ==

imported>Psych2012: /* PCB Layout */

2012-06-09T16:23:50Z

PCB Layout

← Older revision		Revision as of 16:23, 9 June 2012
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	The selection of Resistor Values were a combination of Simulation trials and back-of-the-envelope calculations. The value of maximum current flowing through an LED is 0.5A and with a 1.2 Ohm sense and feedback resistor the expected power is 0.3W. I chose a power value of 0.5W to have some headroom.		The selection of Resistor Values were a combination of Simulation trials and back-of-the-envelope calculations. The value of maximum current flowing through an LED is 0.5A and with a 1.2 Ohm sense and feedback resistor the expected power is 0.3W. I chose a power value of 0.5W to have some headroom.

			Arduino Pins to connect for PWM output: '''Digital pins 2,3,5,6,7,8,11,12,13,44,45,46'''

	Initially I designed a PCB layout and it came back from the printers and some of the through holes were too small. Finally the important through hole/pad dimensions I used were:		Initially I designed a PCB layout and it came back from the printers and some of the through holes were too small. Finally the important through hole/pad dimensions I used were:

imported>Psych2012: /* Appendix II - Work partition */

2012-06-09T16:21:11Z

Appendix II - Work partition

← Older revision		Revision as of 16:21, 9 June 2012
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	<br>		<br>
	Firmware edits - Isaac Chepkwony, Tirthankar Chatterjee		Firmware edits - Isaac Chepkwony, Tirthankar Chatterjee
			<br>
			Help and advice from Robert Dougherty, Research Director Stanford Center for Neurobiological Imaging.

imported>Psych2012: /* PCB Layout */

2012-06-09T16:19:24Z

PCB Layout

← Older revision		Revision as of 16:19, 9 June 2012
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	To calculate the acceptable PCB trace dimensions I used [http://circuitcalculator.com/wordpress/2006/01/31/pcb-trace-width-calculator/ this website]. ExpressPCB specified that according to their manufacturing process the traces usually come out as having a thickness of about 47 um. For the Ambient Temperature Parameter I used 27 degree C, with a tolerance of 15-20 degrees. The trace length I adjusted according to the layout dimensions. I made the PCB design with 2 Metal Layers single sided board design. The picture below shows the final layout.		To calculate the acceptable PCB trace dimensions I used [http://circuitcalculator.com/wordpress/2006/01/31/pcb-trace-width-calculator/ this website]. ExpressPCB specified that according to their manufacturing process the traces usually come out as having a thickness of about 47 um. For the Ambient Temperature Parameter I used 27 degree C, with a tolerance of 15-20 degrees. The trace length I adjusted according to the layout dimensions. I made the PCB design with 2 Metal Layers single sided board design. The picture below shows the final layout.

			The selection of Resistor Values were a combination of Simulation trials and back-of-the-envelope calculations. The value of maximum current flowing through an LED is 0.5A and with a 1.2 Ohm sense and feedback resistor the expected power is 0.3W. I chose a power value of 0.5W to have some headroom.

	Initially I designed a PCB layout and it came back from the printers and some of the through holes were too small. Finally the important through hole/pad dimensions I used were:		Initially I designed a PCB layout and it came back from the printers and some of the through holes were too small. Finally the important through hole/pad dimensions I used were: