Reoprts.LEDAsPhotodiode History

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Changed line 116 from:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had (which was around 20 - 300). Did I miss or mistake anything? I also tried claen-lense green LEDs but still got the same result.
to:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had (which was around 20 - 300). Did I miss or mistake anything? I also tried claen-lens green LEDs but still got the same result.
Changed lines 3-4 from:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but also sensored the touch of fingers. At first, I thought there should be some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode! Actually, the LED, as its name (Light Emitting Diode) implies, is electrically a diode and can be used as a detection device similar to a photodiode. But there are some restrictions:
to:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen on a LED matrix. That LED matrix not only lighted but also sensedthe touch of fingers. At first, I thought there should be some secret behind and the LED matrix he used must be a special one. After discussing and simple trial with Tom Igoe, I found that any LED could be used as photdiode! Actually, the LED, as its name (Light Emitting Diode) implies, is electrically a diode and can be used as a detection device similar to a photodiode. But there are some restrictions:
Changed line 116 from:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything? I also tried claen-lense green LEDs but still got the same result.
to:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had (which was around 20 - 300). Did I miss or mistake anything? I also tried claen-lense green LEDs but still got the same result.
Changed lines 64-65 from:
In [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.MPG | video1 ]](200k, mpg), it shows how the relationship is between LED-matrix and portb.7 LED. Portb.7 LED lights up when I use coverlet on LED matrix. [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.MPG | Video2 ]](250k, mpg) shows that how serial changes accomanpying with the covering.
to:
In [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.MPG | video1 ]](200k, mpg), it shows how the relationship is between LED-matrix and portb.7 LED. Portb.7 LED lights up when I use coverlet on LED matrix. [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.MPG | Video2 ]](250k, mpg) shows that how serial changes accomanpying with covering the LEDs.
Changed lines 64-65 from:
In [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.MPG | video1 ]](200k, mpg), it shows how the relationship is between LED-matrix and portb.7 LED. Portb.7 LED lights up when I use coverlet on LED matrix. [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.MPG | Video2 ]](250, mpg) shows that how serial changes accomanpying with the covering.
to:
In [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.MPG | video1 ]](200k, mpg), it shows how the relationship is between LED-matrix and portb.7 LED. Portb.7 LED lights up when I use coverlet on LED matrix. [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.MPG | Video2 ]](250k, mpg) shows that how serial changes accomanpying with the covering.
Changed lines 64-65 from:
In [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.MPG | video1 ]](880k, avi), it shows how the relationship is between LED-matrix and portb.7 LED. Portb.7 LED lights up when I use coverlet on LED matrix. [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.MPG | Video2 ]](700k, avi) shows that how serial changes accomanpying with the covering.
to:
In [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.MPG | video1 ]](200k, mpg), it shows how the relationship is between LED-matrix and portb.7 LED. Portb.7 LED lights up when I use coverlet on LED matrix. [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.MPG | Video2 ]](250, mpg) shows that how serial changes accomanpying with the covering.
Deleted lines 112-113:
Deleted lines 114-115:
The problem happened probably because I didn't hook power pins up directly and only to analog-in pins.
Changed lines 116-119 from:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything? (I had tried to put resistor between power and LED on porta.0 but in vain. Not sure if I wired in the right way.) -Tom's answer: Change LEDs to those with clean lens.
#The green and yellow LED work pretty well and red LED is totally out of control. Also, super light LED can't tranfer data steadily. Why?
#There is a little bit delay between sensing and lighting. Why?
#When I touch
the power pin of the green LED, the data runs back and forth between 1-3. What does that mean?
to:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything? I also tried claen-lense green LEDs but still got the same result.
#When I touch the power pin of the green LED,
the data runs back and forth between 1-3. What does that happen?
#Why is there a little bit delay between sensing and lighting? Also, the LED is not sensitive so that I think there will be more trouble when I use LED dot matrix. The cover shell will interfere with the sensing substantially.
Changed lines 63-66 from:
http://itp.nyu.edu/~thl238/sensor/LEDSensing/03.jpg
See video here [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.AVI | video1 ]](880k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.AVI | video2 ]](700k, avi).
Video 1 just shows the Row-Column-Scanning I am useing. Then
I change my PicBasic code into 2 parts (as shown below). The fisrt part is row-column-scanning to light LEDs, just like video1. The second part is row-column-scanning to give voltage in reverse way to make LEDs work as photodiodes. But I get nothing changing in serial out, as shown in video 2.
to:
http://itp.nyu.edu/~thl238/sensor/LEDSensing/04.jpg
In [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.MPG | video1 ]](880k, avi), it shows how the relationship is between LED-matrix and portb.7 LED. Portb.7 LED lights up when I use coverlet on LED matrix. [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.MPG | Video2 ]](700k, avi) shows that how serial changes accomanpying with the covering.
Changed lines 68-69 from:
<coming soon>
to:
http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing-schematic2.jpg
Changed lines 1-2 from:
[-Report by Guy Lee, last update 4/3/06-]
to:
[-Report by Guy Lee, last update 4/30/06-]
Changed line 62 from:
In this step, I used 2x2 LED matrix as photodiodes matrix with row-column-scanning. But it didnt work well. The serial data didn't change at all.
to:
In this step, I used 2x2 LED matrix as photodiodes matrix with row-column-scanning. But it didnt work very well. The Leds didn't work separately. Only when did I cover all 4 LEDs that serial numbers started declining from 3.
Changed lines 89-90 from:
adcVar VAR byte[2]
to:
adcVar VAR byte
Changed lines 92-109 from:

high portb.7

'to light LEDs

portd=%00000000
for rows = 0 to 1
dArray.0[rows] = 1
portb=%11111111
for cols = 0 to 1
bArray.0[cols] = 0
pause 50
bArray.0[cols] = 1
next
pause 50
dArray.0 [rows] = 0
next
to:
Changed line 100 from:
pause 1000
to:
pause 10
Changed lines 102-107 from:
serout2 tx, n9600, ["adcVar[",DEC cols,44,DEC rows,"]= ",DEC adcVar[rows],10,13]
to:
serout2 tx, n9600, ["adcVar[",DEC cols,44,DEC rows,"]= ",DEC adcVar[rows],10,13]
if adcVar <=2 then
high portb.7
pause 100
low portb.7
endif
Added lines 114-115:
Changed lines 32-33 from:
What's going on here is when I cover the LED on porta.0 much enough (here means value<=2), the LED on portb.7 will be triggered to light up. Here is my code:
to:
The test is doing when I cover the poarta.0 LED dark enough (seria data value <= 2), tehn the LED on portb.7 will be triggered to light up. Porta.0 LED is reversed by its pins to get negative voltage. Below is my code:
Changed line 62 from:
In this step, I extened to 2x2 LED matrix as photodiodes by row-column-scanning but it didnt run well. The numbers from serial port didn't change. All I got was only 0.
to:
In this step, I used 2x2 LED matrix as photodiodes matrix with row-column-scanning. But it didnt work well. The serial data didn't change at all.
Added lines 128-129:
The problem happened probably because I didn't hook power pins up directly and only to analog-in pins.
Changed lines 17-18 from:
5. [[ http://www.merl.com/projects/LEDcomm/ | Mitsubishi Electric Research Lab : Sensing and Communication Using Bi-Directional LEDs ]]
to:
5. [[ http://www.merl.com/projects/LEDcomm/ | Mitsubishi Electric Research Lab - Sensing and Communication Using Bi-Directional LEDs ]]
Changed lines 17-18 from:
5. [[ http://www.merl.com/projects/LEDcomm/ | Mitsubishi Electric Research Lab:Sensing and Communication Using Bi-Directional LEDs ]]
to:
5. [[ http://www.merl.com/projects/LEDcomm/ | Mitsubishi Electric Research Lab : Sensing and Communication Using Bi-Directional LEDs ]]
Changed lines 21-22 from:
Below are the tests I did:
to:
Below is the test I did:
Changed lines 16-17 from:
4. [[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]
to:
4. [[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]\\
5. [[ http://www.merl.com/projects/LEDcomm/ | Mitsubishi Electric Research Lab:Sensing and Communication Using Bi-Directional LEDs
]]
Changed lines 64-65 from:
to:
Video 1 just shows the Row-Column-Scanning I am useing. Then I change my PicBasic code into 2 parts (as shown below). The fisrt part is row-column-scanning to light LEDs, just like video1. The second part is row-column-scanning to give voltage in reverse way to make LEDs work as photodiodes. But I get nothing changing in serial out, as shown in video 2.
Changed lines 68-69 from:
<picture>
to:
<coming soon>
Changed lines 9-10 from:
#To use the LED as an optical detector, do not forward bias the LED into quadrant # 1 of the current-voltage (I-V). (Quadrant 1 is when the operating voltage and current are both positive.) Allow the LED to operate in the solar cell mode, quadrant #4 (operating voltage is positive, current is negative), or in the photodiode mode quadrant #3 (operating voltage is positive, current is negative).
to:
#To use the LED as an optical detector, do not forward bias the LED into quadrant # 1 of the current-voltage (I-V). (Quadrant 1 is when the operating voltage and current are both positive.) Allow the LED to operate in the solar cell mode, quadrant #4 (operating voltage is positive, current is negative), or in the photodiode mode quadrant #3 (operating voltage is positive, current is negative - ? ).
Changed lines 5-6 from:
'''rule'''
to:
'''Rule'''
Changed lines 3-4 from:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but also sensored the touch of fingers. At first, I thought there should be some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode! Actually, the LED, as its name(Light Emitting Diode) implies, is electrically a diode and can be used as a detection device similar to a photodiode. But there are some restrictions:
to:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but also sensored the touch of fingers. At first, I thought there should be some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode! Actually, the LED, as its name (Light Emitting Diode) implies, is electrically a diode and can be used as a detection device similar to a photodiode. But there are some restrictions:
Changed lines 1-2 from:
[-Report by Guy Lee, last update 3/26/06-]
to:
[-Report by Guy Lee, last update 4/3/06-]
Changed lines 63-64 from:
to:
See video here [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing4.AVI | video1 ]](880k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing5.AVI | video2 ]](700k, avi).
Changed line 126 from:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything? (I had tried to put resistor between power and LED on porta.0 but in vain. Not sure if I wired in the right way.) -Tom's answer: Change your LEDs to those with clean lens.
to:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything? (I had tried to put resistor between power and LED on porta.0 but in vain. Not sure if I wired in the right way.) -Tom's answer: Change LEDs to those with clean lens.
Deleted line 68:
Deleted lines 122-123:
Changed lines 126-127 from:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything? (I had tried to put resistor between power and LED on porta.0 but in vain. Not sure if I wired in the right way.)
Tom's answer: Change your LEDs to those with clean lens.
to:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything? (I had tried to put resistor between power and LED on porta.0 but in vain. Not sure if I wired in the right way.) -Tom's answer: Change your LEDs to those with clean lens.
Changed line 61 from:
In this step, I extened to 3x3 LED matrix as photodiodes by row-column-scanning but it didnt run well. The numbers from serial port didn't change. All I got was only 0.
to:
In this step, I extened to 2x2 LED matrix as photodiodes by row-column-scanning but it didnt run well. The numbers from serial port didn't change. All I got was only 0.
Added line 61:
In this step, I extened to 3x3 LED matrix as photodiodes by row-column-scanning but it didnt run well. The numbers from serial port didn't change. All I got was only 0.
Changed lines 64-65 from:
In this step, I extened to 3x3 LED matrix as photodiodes by row-column-scanning but it didnt run well. The numbers from serial port didn't change. All I got was only 0. Here is my schematic:
to:
Here is my schematic:
Added lines 61-62:
http://itp.nyu.edu/~thl238/sensor/LEDSensing/03.jpg
Changed lines 60-63 from:
In this step, I used LED matrix as photodiode matrix by row-column-scanning but it didnt go well. The numbers didn't change and got all 0. Here is my schematic:

picture
to:

In this step, I extened to 3x3 LED matrix as photodiodes by row-column-scanning but it didnt run well. The numbers from serial port didn't change. All I got was only 0. Here is my schematic:

<picture>
Added line 67:
Added lines 89-103:
'to light LEDs

portd=%00000000
for rows = 0 to 1
dArray.0[rows] = 1
portb=%11111111
for cols = 0 to 1
bArray.0[cols] = 0
pause 50
bArray.0[cols] = 1
next
pause 50
dArray.0 [rows] = 0
next
Changed line 116 from:
bArray.0[cols] = 0
to:
'bArray.0[cols] = 0
Added lines 120-121:
Changed lines 18-19 from:
I am also working on touch panel simultaneously as an input device for my project [[ http://itp.nyu.edu/~thl238/daPass | daPass ]]. However, I prefer to use LED as both my input and output device if I can succeed it hopefully.
to:
I am also working on touch panel simultaneously as an input device for my project [[ http://itp.nyu.edu/~thl238/daPass | daPass ]]. However, I prefer to use LED which can be both input and output device for my project if I can conquer hopefully.
Changed lines 11-12 from:
Related links:
to:
'''Related links'''
Deleted line 11:
Changed lines 15-16 from:
4. [[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]\\
to:
4. [[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]
Changed line 15 from:
3. [http://140.113.239.162/2/modules/news/article.php?storyid=26 | Introduction of diode (Chinese Big5) ]]\\
to:
3. [[ http://140.113.239.162/2/modules/news/article.php?storyid=26 | Introduction of diode (Chinese Big5) ]]\\
Changed lines 13-17 from:
-[[ http://www.sensorsynergy.com/helpfulhints.htm | Using LED as photodiode ]]\\
-[[ http://www.allaboutcircuits.com/vol_3/chpt_3/1.html | Introduction of diode ]]\\
-[http://140.113.239.162/2/modules/news/article.php?storyid=26 | Introduction of diode (Chinese Big5) ]]\\
-[[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]\\
to:
1. [[ http://www.sensorsynergy.com/helpfulhints.htm | Using LED as photodiode ]]\\
2. [[ http://www.allaboutcircuits.com/vol_3/chpt_3/1.html | Introduction of diode ]]\\
3. [http://140.113.239.162/2/modules/news/article.php?storyid=26 | Introduction of diode (Chinese Big5) ]]\\
4. [[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]\\
Changed lines 12-16 from:
-[[ http://www.sensorsynergy.com/helpfulhints.htm | Using LED as photodiode ]]
-[[ http://www.allaboutcircuits.com/vol_3/chpt_3/1.html | Introduction of diode ]]
-[http://140.113.239.162/2/modules/news/article.php?storyid=26 | Introduction of diode (Chinese Big5) ]]
-[[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]
to:
-[[ http://www.sensorsynergy.com/helpfulhints.htm | Using LED as photodiode ]]\\
-[[ http://www.allaboutcircuits.com/vol_3/chpt_3/1.html | Introduction of diode ]]\\
-[http://140.113.239.162/2/modules/news/article.php?storyid=26 | Introduction of diode (Chinese Big5) ]]\\
-[[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]\\
Added line 6:
Changed lines 11-13 from:
To get more information, check [[ http://www.sensorsynergy.com/helpfulhints.htm | here ]].
To know more about photodiode, check [[
http://www.tpub.com/neets/book7/26g.htm | here ]].
to:
Related links:
-[[
http://www.sensorsynergy.com/helpfulhints.htm | Using LED as photodiode ]]
-[[ http://www.allaboutcircuits.com/vol_3/chpt_3/1.html | Introduction of diode ]]
-[http://140.113.239.162/2/modules/news/article.php?storyid=26 | Introduction of diode (Chinese Big5) ]]
-[[ http://www.tpub.com/neets/book7/26g.htm | Introduction of photodiode ]]
Changed lines 19-22 from:
Below is the test I did:

'''test 1'''
to:
Below are the tests I did:

'''[test 1]'''
Changed line 27 from:
'''schematic'''
to:
[schematic]
Added lines 32-33:
[PicBasic code]
Changed line 58 from:
'''test 2'''
to:
'''[test 2]'''
Added lines 13-14:
I am also working on touch panel simultaneously as an input device for my project [[ http://itp.nyu.edu/~thl238/daPass | daPass ]]. However, I prefer to use LED as both my input and output device if I can succeed it hopefully.
Added lines 17-18:
'''test 1'''
Changed lines 52-53 from:
My next step is to apply this on LED matrix to continue my project [[ http://itp.nyu.edu/~thl238/daPass | daPass ]]. Hopefully, it's a better way than using a touch panel for my input and more approaching to what I want!
to:
'''test 2'''
In this step, I used LED matrix as photodiode matrix by row-column-scanning but it didnt go well. The numbers didn't change and got all 0. Here is my schematic:

picture

[PicBasic code]

[@
DEFINE OSC 4

TRISA = %11111111
TrisB = %00000000
TRISC = %10000000
TRISD = %00000000
ADCON1 = %10000010

rows var byte
cols var byte
bArray var portb
dArray var portd
tx var portc.6
rx var portc.7
n9600 con 16468
adcVar VAR byte[2]

main

high portb.7

'LEDs are sensing

for cols = 0 to 1
bArray.0[cols] = 1
portd=%11111111
for rows = 0 to 1
dArray.0[rows] = 0
pause 1000
adcin rows, adcVar[rows]
serout2 tx, n9600, ["adcVar[",DEC cols,44,DEC rows,"]= ",DEC adcVar[rows],10,13]
dArray.0[rows] = 1
next
bArray.0[cols] = 0
next

goto main
@]
Added line 101:
Tom's answer: Change your LEDs to those with clean lens.
Changed lines 11-12 from:
to:
To know more about photodiode, check [[ http://www.tpub.com/neets/book7/26g.htm | here ]].
Changed lines 3-4 from:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but also sensored the touch of fingers. At first, I thought there should be some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode so easily! Below is the test I did:
to:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but also sensored the touch of fingers. At first, I thought there should be some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode! Actually, the LED, as its name(Light Emitting Diode) implies, is electrically a diode and can be used as a detection device similar to a photodiode. But there are some restrictions:

'''rule'''
#LEDs will not respond as rapidly to optical rise and fall times and PN or PIN photodiodes.
#LEDs will only detect light of wavelength shorter than the wavelength of light that the LED would emit if it was put in a circuit that forward biased the LED.
#To use the LED as an optical detector, do not forward bias the LED into quadrant # 1 of the current-voltage (I-V). (Quadrant 1 is when the operating voltage and current are both positive.) Allow the LED to operate in the solar cell mode, quadrant #4 (operating voltage is positive, current is negative), or in the photodiode mode quadrant #3 (operating voltage is positive, current is negative).

To get more information, check [[ http://www.sensorsynergy.com/helpfulhints.htm | here ]].

Below is the test I did:
Changed lines 3-4 from:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but also sensored the touch of fingers. In the begining, I thought there should be some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode so easily! Below is the test I did:
to:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but also sensored the touch of fingers. At first, I thought there should be some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode so easily! Below is the test I did:
Changed line 9 from:
Here is the schematic:
to:
'''schematic'''
Added line 44:
#When I touch the power pin of the green LED, the data runs back and forth between 1-3. What does that mean?
Changed lines 12-13 from:
What is going on here is when I cover the LED on porta.0 much enough, the LED on portb.7 will be triggered to light up. Here is my code:
to:
What's going on here is when I cover the LED on porta.0 much enough (here means value<=2), the LED on portb.7 will be triggered to light up. Here is my code:
Changed lines 7-8 from:
Check video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing3.AVI | video3 ]] (serial data display, 500k, avi). Here is the schematic:
to:
Check video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing3.AVI | video3 ]] (serial data display, 500k, avi).

Here
is the schematic:
Changed lines 7-8 from:
Check video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing3.AVI | video3 ]] (serial data display, 500k, avi).
to:
Check video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing3.AVI | video3 ]] (serial data display, 500k, avi). Here is the schematic:

http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing-schematic.jpg
Changed lines 7-8 from:
Check video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video3 ]] (serial data display, 500k, avi).
to:
Check video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing3.AVI | video3 ]] (serial data display, 500k, avi).
Changed lines 38-39 from:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything?
#The green and yellow LED work pretty well and red LED is totally out of control. Also, super light LED cant tranfer data steadily. Why?
to:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything? (I had tried to put resistor between power and LED on porta.0 but in vain. Not sure if I wired in the right way.)
#The green and yellow LED work pretty well and red LED is totally out of control. Also, super light LED can't
tranfer data steadily. Why?
Changed lines 9-10 from:
When I covered the LED on porta.0 much enough, the LED on portb.7 would be triggered to light up. Here is my code:
to:
What is going on here is when I cover the LED on porta.0 much enough, the LED on portb.7 will be triggered to light up. Here is my code:
Changed lines 7-8 from:
Video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video3 ]] (serial data display, 500k, avi).
to:
Check video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video3 ]] (serial data display, 500k, avi).
Changed line 5 from:
I used porta.0 for wiring a LED analog in and portb.7 for another LED output.
to:
I used porta.0 for a LED analog-in and portb.7 for another LED output.
Changed line 38 from:
#I got numbers of range only 0 - 3, instead of what Tom Igoe had yesterday 20 - 300. Did I miss or mistake anything?
to:
#I got numbers of range only 0 - 3, much less beautiful than what Tom Igoe had yesterday (which was around 20 - 300). Did I miss or mistake anything?
Changed line 38 from:
#I only got numbers of range 0 - 3, instead of what Tom Igoe had yesterday around 20 - 300. Did I miss anything?
to:
#I got numbers of range only 0 - 3, instead of what Tom Igoe had yesterday 20 - 300. Did I miss or mistake anything?
Changed lines 3-4 from:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but sensored the touch of fingers. In the begining, I thought there should some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode easily! Below is the test I did:
to:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but also sensored the touch of fingers. In the begining, I thought there should be some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode so easily! Below is the test I did:
Added lines 35-36:
My next step is to apply this on LED matrix to continue my project [[ http://itp.nyu.edu/~thl238/daPass | daPass ]]. Hopefully, it's a better way than using a touch panel for my input and more approaching to what I want!
Changed lines 3-5 from:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han
]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but sensored the touch of fingers. In the begining, I thought there should some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode easily! Below is the test I did:
to:
In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han ]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but sensored the touch of fingers. In the begining, I thought there should some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode easily! Below is the test I did:
Changed lines 7-8 from:
Video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, .avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, .avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video3 ]] (serial data display, 500k, .avi).
to:
Video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video3 ]] (serial data display, 500k, avi).
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#
to:
#There is a little bit delay between sensing and lighting. Why?
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[-Report by Guy Lee, last update 3/26/06-]

In the project [[ http://mrl.nyu.edu/~jhan/ledtouch/index.html | LED Touch Sensing ]] by [[ http://mrl.nyu.edu/~jhan/ | Jeff Han
]], I saw a magic happen to a LED matrix. That LED matrix not only lighted but sensored the touch of fingers. In the begining, I thought there should some secret behind and the LED matrix he used must be some special treasure. After discussing with Tom Igoe, I found that any LED could be used as photdiode easily! Below is the test I did:

I used porta.0 for wiring a LED analog in and portb.7 for another LED output.
http://itp.nyu.edu/~thl238/sensor/LEDSensing/01.jpg http://itp.nyu.edu/~thl238/sensor/LEDSensing/02.jpg
Video here: [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video1 ]] (800k, .avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing2.AVI | video2 ]] (500k, .avi), [[ http://itp.nyu.edu/~thl238/sensor/LEDSensing/LEDSensing1.AVI | video3 ]] (serial data display, 500k, .avi).

When I covered the LED on porta.0 much enough, the LED on portb.7 would be triggered to light up. Here is my code:

[@
DEFINE OSC 4

TRISA = %11111111
ADCON1 = %10000010
tx var portc.6
rx var portc.7
n9600 con 16468
adcVar var word

main

adcin 0, adcVar
serout2 tx, n9600, [DEC adcVar, 13]
if adcVar<=2 then
high portb.7
else
low portb.7
endif
pause 100

goto main
@]

'''Questions'''
#I only got numbers of range 0 - 3, instead of what Tom Igoe had yesterday around 20 - 300. Did I miss anything?
#The green and yellow LED work pretty well and red LED is totally out of control. Also, super light LED cant tranfer data steadily. Why?
#