Led sensor - Revision history

FabienM: /* How does it work ? */

2008-09-25T19:33:00Z

‎How does it work ?

2008-09-25T19:32:30Z

Undo revision 4655 by FabienM (Talk)

2008-09-25T19:29:04Z

2008-09-25T19:22:24Z

‎How does it work ?

2008-09-25T19:03:19Z

‎How does it work ?

2008-09-24T20:55:32Z

2008-08-24T18:26:52Z

2008-08-04T20:28:58Z

2008-08-03T19:31:35Z

2008-08-03T19:14:13Z

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 To test this phenomena, I have used a pin of the FPGA, and design a little component/IP that provides the discharging time in a register.
 = How does it work ? =
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 When led is charged, fsm disconnect ''cathode'' and count until the ''value''
-reach 0. The result of count is available on 16bits read register.
+reach 0. The result of count is available on 16bits read register (named
 [[Image:ledtouchgraph.png|500px|center]]

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 = How does it work ? =
@@ Line 19: / Line 23: @@
 When led is charged, fsm disconnect ''cathode'' and count until the ''value''
-reach 0. The result of count is available on 16bits read register (named
+reach 0. The result of count is available on 16bits read register.
-counter). Counter can be convert in time with formula :
 [[Image:ledtouchgraph.png|500px|center]]

@@ Line 1: / Line 1: @@
 = How does it work ? =
@@ Line 23: / Line 19: @@
 When led is charged, fsm disconnect ''cathode'' and count until the ''value''
-reach 0. The result of count is available on 16bits read register.
+reach 0. The result of count is available on 16bits read register (named
 [[Image:ledtouchgraph.png|500px|center]]

@@ Line 7: / Line 7: @@
 Ledsensor ip formed by by four entities :
-[[Image:structledtouch.png|300px|center]]
+[[Image:structledtouch.png|500px|center]]
@@ Line 18: / Line 18: @@
 [[Image:ledtouchschema.png|300px|center]]
 = Code =

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 Ledsensor ip formed by by four entities :
 * '''cnt''' : like «counter» this entity provide counter to measure ledcapacitor discharge, it also provide charge period timing.
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 * '''fsm''' : This is the main component of the IP, this state machine drive the component. The working of the fsm is describe below :
 = Code =

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-According to [http://www.merl.com/reports/docs/TR2003-35.pdf this] paper, a simple led can be a light sensor if it used in reverse mode. In fact if led is used in invert, it become a variable capacitance.
+According to [http://www.merl.com/reports/docs/TR2003-35.pdf this paper], a simple LED can be a light sensor if used in reverse mode. In fact if LED is used in invert, it becomes a variable capacitance.
+To test this phenomena, I have used a pin of the FPGA, and design a little component/IP that provides the discharging time in a register.
-To test this phenomena , I used to pin of the FPGA, and design a little component that provide the discharging time in a register.
 = Code =
@@ Line 8: / Line 7: @@
 [http://fabienmarteau.free.fr/images/synthesis.tar.gz here]
-= How that work ? =
+= How does it work ? =
 [[Image:ledtouchschema.png|300px|center]]
 = Results =
-With a green standard led that give :
+With a green standard led, that gives :
 [[Image:greenplot.png|300px|center]]

← Older revision		Revision as of 20:28, 4 August 2008
Line 3:		Line 3:

	To test this phenomena , I used to pin of the FPGA, and design a little component that provide the discharging time in a register.		To test this phenomena , I used to pin of the FPGA, and design a little component that provide the discharging time in a register.
		+
		+	= Code =
		+
		+	[http://fabienmarteau.free.fr/images/synthesis.tar.gz here]

	= How that work ? =		= How that work ? =

← Older revision		Revision as of 19:14, 3 August 2008
Line 4:		Line 4:
	To test this phenomena , I used to pin of the FPGA, and design a little component that provide the discharging time in a register.		To test this phenomena , I used to pin of the FPGA, and design a little component that provide the discharging time in a register.

−	[[Image:ledtouchschema.png]]	+
		+	[[Image:ledtouchschema.png\|300px\|center]]