Reports.GP2D120 History

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and make sure it doesnít add up to more than the amounf of current your voltage regulator can
to:
and make sure it doesnít add up to more than the amount of current your voltage regulator can
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Crys Moore did a nice write-up on [[http://itp.nyu.edu/~cm2878/crysmoore/?p=518| linearizing these sensors]] using Acroname's formulas on an Arduino. ''-tigoe''
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As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and the relatively narrow focus cone of the sensor outweighs the negatives for me. In certain ways, the ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]
to:
As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and the relatively narrow focus cone of the sensor outweighs the negatives for me. In certain ways, the Ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]
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'''The Sharp GP2D120'''

Original report: [[~pf372 | Paul Feder]]

ThisWiki:/uploads/Reports/gp.jpg

This is an Infrared (IR) sensor that detects changes in distance to an object
and outputs an analog voltage corresponding to how close or far away the object is to the sensor.
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The range of values that you get when connected to a computer through serial is about half of the 0-1023 range of a Potentiometer.

[[http://acroname.com/robotics/parts/R146-GP2D120.html |Acroname's page]] on the Sharp GP2D120\\
''this is a useful page. But a link to the original [[http://www.datasheetarchive.com/semiconductors/download.php?Datasheet=815287 |Sharp datasheet]] would be helpful as well. -[[~tigoe]]''


'''PROS and CONS'''
As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and the relatively narrow focus cone of the sensor outweighs the negatives for me. In certain ways, the ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]


'''Weak Points:'''

1. They have a dead zone right in front of the sensor which will yield garbage data.

2. They are nonlinear, and using an equation to convert it to linear data is processor heavy.

3. They have difficulty detecting transparent material.

4. They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire.

5. The readings have a fair bit of noise- you have to do some software filtering to smooth out the results.

'''Strong Points:'''

1. They are relatively cheap.

2. They are very easy to set up and use.

3. They have a rather focused beam of detection, which is a plus depending on the application.



'''How it works'''

[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]

Basically, there is an infrared emitting LED, and a lens, side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:

ThisWiki:/uploads/Reports/triangle.gif

The connections are pretty simple. There are three wires: Power (Vcc), Ground (GND), and Output (Vo).
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector (''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]'')

I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast.

Here are the Min/ Typ/ Max ratings when using a white piece of paper as the object the IR sensor is sensing.

* '''Measuring Distance (Range, or delta L)''': 4 cm - 30 cm
* '''Supply Voltage (Vcc)''': Happy: 4.5 V Ė 5.5 V (Unhappy: Min Ė0.3 V, Max 7 V)
* '''Output terminal voltage (Vo)''': Min 0.25 V, Typical 0.4 V, Max 0.55 V
* '''Output voltage difference (delta Vo)''': Min 1.75 V, Typical 2.0 V, Max 2.25 V
* '''The average supply current (Icc'''): Typical 33 mA, Max 50 mA

'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable. Here's a graph of the GP2D120's output curve (Y axis is Output Voltage (Vo), and the X axis is distance measured in cm):

ThisWiki:/uploads/Reports/120Graph.jpg

Here's a link to acroname's site, where they explain how to make the curve linear. I had trouble getting it to work perfectly however:
[[http://acroname.com/robotics/info/articles/irlinear/irlinear.html | How to make the output linear.]]

'''Supply Voltage (Vcc) Explained:''' This sensor is happiest when itís getting 4.5 Ė 5.5 V!

'''Output Voltage''' ''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''

'''Average Supply Current Explained:''' The Max current is what you would want to keep in
mind if you have a lot of other electronics hooked up to the breadboard.
You would want to find the sum of all the Max current values of all your electronics
and make sure it doesnít add up to more than the amounf of current your voltage regulator can
supply (e.g. 1000mA for a 7805 5V regulator).


'''Robotic Applications'''

I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. [[http://www.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]] The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]


'''Musical Applications'''

The IR sensor can be used to make a simple theremin instrument, which can raise and lower pitch depending on how close your hand is to the sensor.

Iíve been working on a musical instrument that uses two GPD120 sensors. The instrument is a cube that generates melodies (using Max/Msp), and I can tweak the phrasing of the melodies by waving my hands back and forth. In order to get around the dead zone issue, I constructed a box with a hole on two sides, with my two sensors mounted 2 inches back from the surface of the box. This way, I can bring my hands right up to the box without worrying about hitting that dead zone of the sensor.

In order to get around the noise of the sensor, through software, I lopped off a little bit of the range of the sensor on either end. Even though I lose a bit of range, the increased reliability is a big plus. The reason I took off the range far from the sensor is to ensure that any fluctuations in the sensor when there is nothing present wonít be sent to Max/MSP. The reason I took off some of the range close to the sensor is that even though I designed the cube in order so that I could bring my hand right up to the hole, the palm of my hand is not fully flush with the box, and therefore canít get exactly to the minimum distance the way a flat piece of paper would. By limiting the range, my hand can be right nexta to the box, or slightly away from the box, and both will give end of range values.
Deleted lines 0-92:
'''The Sharp GP2D120'''

Original report: [[~pf372 | Paul Feder]]

ThisWiki:/uploads/Reports/gp.jpg

This is an Infrared (IR) sensor that detects changes in distance to an object
and outputs an analog voltage corresponding to how close or far away the object is to the sensor.
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The range of values that you get when connected to a computer through serial is about half of the 0-1023 range of a Potentiometer.

[[http://acroname.com/robotics/parts/R146-GP2D120.html |Acroname's page]] on the Sharp GP2D120\\
''this is a useful page. But a link to the original [[http://www.datasheetarchive.com/semiconductors/download.php?Datasheet=815287 |Sharp datasheet]] would be helpful as well. -[[~tigoe]]''


'''PROS and CONS'''
As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and the relatively narrow focus cone of the sensor outweighs the negatives for me. In certain ways, the ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]


'''Weak Points:'''

1. They have a dead zone right in front of the sensor which will yield garbage data.

2. They are nonlinear, and using an equation to convert it to linear data is processor heavy.

3. They have difficulty detecting transparent material.

4. They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire.

5. The readings have a fair bit of noise- you have to do some software filtering to smooth out the results.

'''Strong Points:'''

1. They are relatively cheap.

2. They are very easy to set up and use.

3. They have a rather focused beam of detection, which is a plus depending on the application.



'''How it works'''

[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]

Basically, there is an infrared emitting LED, and a lens, side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:

ThisWiki:/uploads/Reports/triangle.gif

The connections are pretty simple. There are three wires: Power (Vcc), Ground (GND), and Output (Vo).
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector (''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]'')

I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast.

Here are the Min/ Typ/ Max ratings when using a white piece of paper as the object the IR sensor is sensing.

* '''Measuring Distance (Range, or delta L)''': 4 cm - 30 cm
* '''Supply Voltage (Vcc)''': Happy: 4.5 V Ė 5.5 V (Unhappy: Min Ė0.3 V, Max 7 V)
* '''Output terminal voltage (Vo)''': Min 0.25 V, Typical 0.4 V, Max 0.55 V
* '''Output voltage difference (delta Vo)''': Min 1.75 V, Typical 2.0 V, Max 2.25 V
* '''The average supply current (Icc'''): Typical 33 mA, Max 50 mA

'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable. Here's a graph of the GP2D120's output curve (Y axis is Output Voltage (Vo), and the X axis is distance measured in cm):

ThisWiki:/uploads/Reports/120Graph.jpg

Here's a link to acroname's site, where they explain how to make the curve linear. I had trouble getting it to work perfectly however:
[[http://acroname.com/robotics/info/articles/irlinear/irlinear.html | How to make the output linear.]]

'''Supply Voltage (Vcc) Explained:''' This sensor is happiest when itís getting 4.5 Ė 5.5 V!

'''Output Voltage''' ''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''

'''Average Supply Current Explained:''' The Max current is what you would want to keep in
mind if you have a lot of other electronics hooked up to the breadboard.
You would want to find the sum of all the Max current values of all your electronics
and make sure it doesnít add up to more than the amounf of current your voltage regulator can
supply (e.g. 1000mA for a 7805 5V regulator).


'''Robotic Applications'''

I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. [[http://www.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]] The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]


'''Musical Applications'''

The IR sensor can be used to make a simple theremin instrument, which can raise and lower pitch depending on how close your hand is to the sensor.

Iíve been working on a musical instrument that uses two GPD120 sensors. The instrument is a cube that generates melodies (using Max/Msp), and I can tweak the phrasing of the melodies by waving my hands back and forth. In order to get around the dead zone issue, I constructed a box with a hole on two sides, with my two sensors mounted 2 inches back from the surface of the box. This way, I can bring my hands right up to the box without worrying about hitting that dead zone of the sensor.

In order to get around the noise of the sensor, through software, I lopped off a little bit of the range of the sensor on either end. Even though I lose a bit of range, the increased reliability is a big plus. The reason I took off the range far from the sensor is to ensure that any fluctuations in the sensor when there is nothing present wonít be sent to Max/MSP. The reason I took off some of the range close to the sensor is that even though I designed the cube in order so that I could bring my hand right up to the hole, the palm of my hand is not fully flush with the box, and therefore canít get exactly to the minimum distance the way a flat piece of paper would. By limiting the range, my hand can be right nexta to the box, or slightly away from the box, and both will give end of range values.
Changed lines 9-10 from:
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The range of values that you get when connected to a computer through serial is about half of the 0-1023 range of a Potentiometer. Also, it is much noisier than a Pot. However, it is a super-cool sensor!
to:
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The range of values that you get when connected to a computer through serial is about half of the 0-1023 range of a Potentiometer.
Changed lines 15-17 from:
As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and set-up outweighs the negatives. In certain ways, the ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]
to:
'''PROS and CONS'''
As I have
discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and the relatively narrow focus cone of the sensor outweighs the negatives for me. In certain ways, the ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]
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'''The Sharp GP2D120'''

Original report: [[~pf372 | Paul Feder]]

ThisWiki:/uploads/Reports/gp.jpg

This is an Infrared (IR) sensor that detects changes in distance to an object
and outputs an analog voltage corresponding to how close or far away the object is to the sensor.
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The range of values that you get when connected to a computer through serial is about half of the 0-1023 range of a Potentiometer. Also, it is much noisier than a Pot. However, it is a super-cool sensor!

[[http://acroname.com/robotics/parts/R146-GP2D120.html |Acroname's page]] on the Sharp GP2D120\\
''this is a useful page. But a link to the original [[http://www.datasheetarchive.com/semiconductors/download.php?Datasheet=815287 |Sharp datasheet]] would be helpful as well. -[[~tigoe]]''


As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and set-up outweighs the negatives. In certain ways, the ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]


'''Weak Points:'''

1. They have a dead zone right in front of the sensor which will yield garbage data.

2. They are nonlinear, and using an equation to convert it to linear data is processor heavy.

3. They have difficulty detecting transparent material.

4. They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire.

5. The readings have a fair bit of noise- you have to do some software filtering to smooth out the results.

'''Strong Points:'''

1. They are relatively cheap.

2. They are very easy to set up and use.

3. They have a rather focused beam of detection, which is a plus depending on the application.


'''How it works'''

[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]

Basically, there is an infrared emitting LED, and a lens, side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:

ThisWiki:/uploads/Reports/triangle.gif

The connections are pretty simple. There are three wires: Power (Vcc), Ground (GND), and Output (Vo).
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector (''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]'')

I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast.

Here are the Min/ Typ/ Max ratings when using a white piece of paper as the object the IR sensor is sensing.

* '''Measuring Distance (Range, or delta L)''': 4 cm - 30 cm
* '''Supply Voltage (Vcc)''': Happy: 4.5 V Ė 5.5 V (Unhappy: Min Ė0.3 V, Max 7 V)
* '''Output terminal voltage (Vo)''': Min 0.25 V, Typical 0.4 V, Max 0.55 V
* '''Output voltage difference (delta Vo)''': Min 1.75 V, Typical 2.0 V, Max 2.25 V
* '''The average supply current (Icc'''): Typical 33 mA, Max 50 mA

'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable. Here's a graph of the GP2D120's output curve (Y axis is Output Voltage (Vo), and the X axis is distance measured in cm):

ThisWiki:/uploads/Reports/120Graph.jpg

Here's a link to acroname's site, where they explain how to make the curve linear. I had trouble getting it to work perfectly however:
[[http://acroname.com/robotics/info/articles/irlinear/irlinear.html | How to make the output linear.]]

'''Supply Voltage (Vcc) Explained:''' This sensor is happiest when itís getting 4.5 Ė 5.5 V!

'''Output Voltage''' ''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''


'''Average Supply Current Explained:''' The Max current is what you would want to keep in
mind if you have a lot of other electronics hooked up to the breadboard.
You would want to find the sum of all the Max current values of all your electronics
and make sure it doesnít add up to more than the amounf of current your voltage regulator can
supply (e.g. 1000mA for a 7805 5V regulator).


'''Robotic Applications'''

I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. [[http://www.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]] The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]

'''Musical Applications'''

The IR sensor can be used to make a simple theremin instrument, which can raise and lower pitch depending on how close your hand is to the sensor.

Iíve been working on a musical instrument that uses two GPD120 sensors. The instrument is a cube that generates melodies (using Max/Msp), and I can tweak the phrasing of the melodies by waving my hands back and forth. In order to get around the dead zone issue, I constructed a box with a hole on two sides, with my two sensors mounted 2 inches back from the surface of the box. This way, I can bring my hands right up to the box without worrying about hitting that dead zone of the sensor.

In order to get around the noise of the sensor, through software, I lopped off a little bit of the range of the sensor on either end. Even though I lose a bit of range, the increased reliability is a big plus. The reason I took off the range far from the sensor is to ensure that any fluctuations in the sensor when there is nothing present wonít be sent to Max/MSP. The reason I took off some of the range close to the sensor is that even though I designed the cube in order so that I could bring my hand right up to the hole, the palm of my hand is not fully flush with the box, and therefore canít get exactly to the minimum distance the way a flat piece of paper would. By limiting the range, my hand can be right nexta to the box, or slightly away from the box, and both will give end of range values.
Deleted lines 0-88:
'''The Sharp GP2D120'''

Original report: [[~pf372 | Paul Feder]]

ThisWiki:/uploads/Reports/gp.jpg

This is an Infrared (IR) sensor that detects changes in distance to an object
and outputs an analog voltage corresponding to how close or far away the object is to the sensor.
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The range of values that you get when connected to a computer through serial is about half of the 0-1023 range of a Potentiometer. Also, it is much noisier than a Pot. However, it is a super-cool sensor!

[[http://acroname.com/robotics/parts/R146-GP2D120.html |Acroname's page]] on the Sharp GP2D120\\
''this is a useful page. But a link to the original [[http://www.datasheetarchive.com/semiconductors/download.php?Datasheet=815287 |Sharp datasheet]] would be helpful as well. -[[~tigoe]]''


As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and set-up outweighs the negatives. In certain ways, the ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]


'''Weak Points:'''

1. They have a dead zone right in front of the sensor which will yield garbage data.

2. They are nonlinear, and using an equation to convert it to linear data is processor heavy.

3. They have difficulty detecting transparent material.

4. They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire.

5. The readings have a fair bit of noise- you have to do some software filtering to smooth out the results.

'''Strong Points:'''

1. They are relatively cheap.

2. They are very easy to set up and use.

3. They have a rather focused beam of detection, which is a plus depending on the application.


'''How it works'''

[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]

Basically, there is an infrared emitting LED, and a lens, side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:

ThisWiki:/uploads/Reports/triangle.gif

The connections are pretty simple. There are three wires: Power (Vcc), Ground (GND), and Output (Vo).
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector (''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]'')

I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast.

Here are the Min/ Typ/ Max ratings when using a white piece of paper as the object the IR sensor is sensing.

* '''Measuring Distance (Range, or delta L)''': 4 cm - 30 cm
* '''Supply Voltage (Vcc)''': Happy: 4.5 V Ė 5.5 V (Unhappy: Min Ė0.3 V, Max 7 V)
* '''Output terminal voltage (Vo)''': Min 0.25 V, Typical 0.4 V, Max 0.55 V
* '''Output voltage difference (delta Vo)''': Min 1.75 V, Typical 2.0 V, Max 2.25 V
* '''The average supply current (Icc'''): Typical 33 mA, Max 50 mA

'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable. Here's a graph of the GP2D120's output curve (Y axis is Output Voltage (Vo), and the X axis is distance measured in cm):

ThisWiki:/uploads/Reports/120Graph.jpg

Here's a link to acroname's site, where they explain how to make the curve linear. I had trouble getting it to work perfectly however:
[[http://acroname.com/robotics/info/articles/irlinear/irlinear.html | How to make the output linear.]]

'''Supply Voltage (Vcc) Explained:''' This sensor is happiest when itís getting 4.5 Ė 5.5 V!

'''Output Voltage''' ''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''


'''Average Supply Current Explained:''' The Max current is what you would want to keep in
mind if you have a lot of other electronics hooked up to the breadboard.
You would want to find the sum of all the Max current values of all your electronics
and make sure it doesnít add up to more than the amounf of current your voltage regulator can
supply (e.g. 1000mA for a 7805 5V regulator).


'''Robotic Application'''

I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. [[http://www.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]] The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]

'''Musical Application'''

Iíve been working on a musical instrument that uses two GPD120 sensors. The instrument is a cube that generates melodies (using Max/Msp), and I can tweak the phrasing of the melodies by waving my hands back and forth. In order to get around the dead zone issue, I constructed a box with a hole on two sides, with my two sensors mounted 2 inches back from the surface of the box. This way, I can bring my hands right up to the box without worrying about hitting that dead zone of the sensor.

In order to get around the noise of the sensor, through software, I lopped off a little bit of the range of the sensor on either end. Even though I lose a bit of range, the increased reliability is a big plus. The reason I took off the range far from the sensor is to ensure that any fluctuations in the sensor when there is nothing present wonít be sent to Max/MSP. The reason I took off some of the range close to the sensor is that even though I designed the cube in order so that I could bring my hand right up to the hole, the palm of my hand is not fully flush with the box, and therefore canít get exactly to the minimum distance the way a flat piece of paper would. By limiting the range, my hand can be right next to the box, or slightly away from the box, and both will give end of range values.
Changed lines 64-66 from:
to:
Here's a link to acroname's site, where they explain how to make the curve linear. I had trouble getting it to work perfectly however:
[[http://acroname.com/robotics/info/articles/irlinear/irlinear.html | How to make the output linear.]]
Changed lines 87-89 from:
In order to get around the noise of the sensor, through software, I lopped off a little bit of the range of the sensor on either end. Even though I lose a bit of range, the increased reliability is a big plus. The reason I took off the range far from the sensor is to ensure that any fluctuations in the sensor when there is nothing present wonít be sent to Max/MSP. The reason I took off some of the range close to the sensor is that even though I designed the cube in order so that I could bring my hand right up to the hole, the palm of my hand is not fully flush with the box, and therefore canít get exactly to the minimum distance the way a flat piece of paper would. By limiting the range, my hand can be all the way up to the box, or slightly away from the box, and both will give end of range values.
to:
In order to get around the noise of the sensor, through software, I lopped off a little bit of the range of the sensor on either end. Even though I lose a bit of range, the increased reliability is a big plus. The reason I took off the range far from the sensor is to ensure that any fluctuations in the sensor when there is nothing present wonít be sent to Max/MSP. The reason I took off some of the range close to the sensor is that even though I designed the cube in order so that I could bring my hand right up to the hole, the palm of my hand is not fully flush with the box, and therefore canít get exactly to the minimum distance the way a flat piece of paper would. By limiting the range, my hand can be right next to the box, or slightly away from the box, and both will give end of range values.
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'''Applications'''
to:
'''Robotic Application'''
Changed lines 81-82 from:
Musical Instrument:
to:
'''Musical Application'''
Changed lines 79-87 from:
I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. [[http://www.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]]

The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher
accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]


to:
I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. [[http://www.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]] The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]

Musical Instrument:

Iíve been working on a musical instrument that uses two GPD120 sensors. The instrument is a cube that generates melodies (using Max/Msp), and I can tweak the phrasing of the melodies by waving my hands back and forth. In order to get around the dead zone issue, I constructed a box with a hole on two sides, with my two sensors mounted 2 inches back from the surface of the box. This way, I can bring my hands right up to the box without worrying about hitting that dead zone of the sensor.

In order to get around the noise of the sensor, through software, I lopped off a little bit of the range of the sensor on either end. Even though I lose a bit of range, the increased reliability is a big plus. The reason I took off the range far from the sensor is to ensure that any fluctuations in the sensor when there is nothing present wonít be sent to Max/MSP. The reason I took off some of the range close to the sensor is that even though I designed the cube in order so that I could bring my hand right up to the hole, the palm of my hand is not fully flush with the box, and therefore canít get exactly to the minimum distance the way a flat piece of paper would. By limiting the range, my hand can be all the way up to the box, or slightly away from the box, and both will give end of range values.
Changed lines 15-16 from:
As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and set-up outweighs the negatives.
to:
As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and set-up outweighs the negatives. In certain ways, the ultrasonic sensor is more reliable in more situations than the IR. Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors: [[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]
Changed lines 83-89 from:
Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors:
[[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]


[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | Same Link as earlier in Sensor Report - A good intro to IR]]
to:

Changed lines 79-80 from:
The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]
to:
The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]
Changed lines 78-80 from:
I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications.
[[http://www
.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]]
to:
I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. [[http://www.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]]
The conclusion of this article was that they would use IR
sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications. For instance, this R2-D2 look-alike: [[http://acroname.com/robotics/gallery/ja/ja.html | JA bot]]
Changed lines 78-79 from:
[[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]
to:
I found an interesting presentation online for a "Smart Wheelchair" design, which uses Sharp IR sensors. The conclusion of this article was that they would use IR sensors in conjunction with Ultrasonic sensors for redundancy and thus higher accuracy. This method seems to be popular in many robotics applications.
Added lines 81-84:
Here is an article that delves into the limitations of the IR sensors and Ultrasonic sensors:
[[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]
Changed lines 82-84 from:
[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]
to:
[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | Same Link as earlier in Sensor Report - A good intro to IR]]
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Added line 81:
Added line 84:
Changed lines 79-81 from:
to:
[[http://www.wheelchairnet.org/WCN_WCU/SlideLectures/2002%20resna/LoPresti_RESNA2002/LoPresti.html | Smart Wheelchair with IR]]
[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]
Changed lines 78-79 from:
[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]
to:
[[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]]
Changed lines 78-79 from:
[[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]
to:
[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]
Changed lines 9-10 from:
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The values that you get when connected to a computer through serial range from about 0-600, rather than the full 0-1023 range of a Potentiometer. Also, it is much noisier than a Pot. However, it is a super-cool sensor!
to:
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The range of values that you get when connected to a computer through serial is about half of the 0-1023 range of a Potentiometer. Also, it is much noisier than a Pot. However, it is a super-cool sensor!
Changed lines 14-21 from:
'''How it works'''

[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]

Basically, there is an infrared emitting LED, and a lens, side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:

ThisWiki:/uploads/Reports/triangle.gif
to:
Changed lines 38-45 from:
to:
'''How it works'''

[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]

Basically, there is an infrared emitting LED, and a lens, side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:

ThisWiki:/uploads/Reports/triangle.gif
Changed lines 76-79 from:
to:
'''Applications'''

[[http://www.techgeek.com/subpage/index.phtml?topic=998 | Ultrasonic and IR Sensors Compared]
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to:
As I have discovered, there are some major weaknesses in IR sensors, listed below. However, all in all, the simplicity of use and set-up outweighs the negatives.
Changed lines 22-26 from:
The connections are pretty simple. There are three wires: Power (Vcc), Ground (GND), and Output (Vo).
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector (''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]'')

I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast.
to:
Added line 38:
Changed lines 40-45 from:
3. They have a rather focused beam of detection, which is a plus depending on the application (if you want a more general sweep of an area, an ultrasonic sensor might be better).


to:

3. They have a rather focused beam of detection, which is a plus depending on the application.



The connections are pretty simple. There are three wires: Power (Vcc), Ground (GND), and Output (Vo).
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector (''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]'')

I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast.
Changed lines 29-32 from:
1. They have a dead zone right in front of the sensor which will yield garbage data. <br>
2.
They are nonlinear, and using an equation to convert it to linear data is processor heavy. <br>
3. They have difficulty detecting transparent material. <br>
4.
They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire. <br>
to:
1. They have a dead zone right in front of the sensor which will yield garbage data.

2.
They are nonlinear, and using an equation to convert it to linear data is processor heavy.

3. They have difficulty detecting transparent material.

4.
They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire.
Changed lines 29-32 from:
1. They have a dead zone right in front of the sensor which will yield garbage data.
2. They are nonlinear, and using an equation to convert it to linear data is processor heavy.
3. They have difficulty detecting transparent material.
4. They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire.
to:
1. They have a dead zone right in front of the sensor which will yield garbage data. <br>
2.
They are nonlinear, and using an equation to convert it to linear data is processor heavy. <br>
3. They have difficulty detecting transparent material. <br>
4. They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire. <br>
Added lines 27-44:
'''Weak Points:'''

1. They have a dead zone right in front of the sensor which will yield garbage data.
2. They are nonlinear, and using an equation to convert it to linear data is processor heavy.
3. They have difficulty detecting transparent material.
4. They are subject to interference from other sources of IR light. For instance, if you point a remote control at it, the readings will go haywire.
5. The readings have a fair bit of noise- you have to do some software filtering to smooth out the results.

'''Strong Points:'''

1. They are relatively cheap.
2. They are very easy to set up and use.
3. They have a rather focused beam of detection, which is a plus depending on the application (if you want a more general sweep of an area, an ultrasonic sensor might be better).



Changed lines 2-4 from:
[[http://acroname.com/robotics/parts/R146-GP2D120.html |Acroname's page]] on the Sharp GP2D120\\
''this is a useful page. But a link to the original [[http://www.datasheetarchive.com/semiconductors/download.php?Datasheet=815287 |Sharp datasheet]] would be helpful as well. -[[~tigoe]]''
to:
Added lines 11-13:
[[http://acroname.com/robotics/parts/R146-GP2D120.html |Acroname's page]] on the Sharp GP2D120\\
''this is a useful page. But a link to the original [[http://www.datasheetarchive.com/semiconductors/download.php?Datasheet=815287 |Sharp datasheet]] would be helpful as well. -[[~tigoe]]''
Changed lines 11-12 from:
It is almost identical to the GP2D12, only the GP2D120 has a shorter range.
to:
It is almost identical to the GP2D12, only the GP2D120 has a shorter range. The values that you get when connected to a computer through serial range from about 0-600, rather than the full 0-1023 range of a Potentiometer. Also, it is much noisier than a Pot. However, it is a super-cool sensor!
Changed lines 34-35 from:
'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable. Here's a graph of the GP2D120's output curve:
to:
'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable. Here's a graph of the GP2D120's output curve (Y axis is Output Voltage (Vo), and the X axis is distance measured in cm):
Changed lines 36-38 from:
[[Attach:Graph.jpg]
to:
ThisWiki:/uploads/Reports/120Graph.jpg
Changed lines 34-37 from:
'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable.
to:
'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable. Here's a graph of the GP2D120's output curve:

[[Attach:Graph.jpg]
Changed lines 40-42 from:
Output Voltage ''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''
to:
'''Output Voltage''' ''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''
Changed lines 22-25 from:
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector.
''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]''
I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast, freaking my microprocessor out.
to:
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector (''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]'')

I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast.
Changed lines 36-37 from:
''a graph of the range, and a diagram of the sensor might help here -[[~tigoe]]''
to:
Changed lines 14-16 from:
[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor]]
There is an Infrared Emitting LED
, and an Infrared reciever (which is a lens), side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:
to:
[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor can be found here, at Acroname]]

Basically, there is an infrared emitting LED
, and a lens, side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:
Changed lines 23-24 from:
Et Voila!
to:
''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]''
I've tried to use the GP2D120 without a by-pass capacitor, and my Pic chip would lose power, and restart, because presumably the detector drew too much current too fast, freaking my microprocessor out.
Changed lines 40-41 from:
Output Voltage*
to:
Output Voltage ''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''
Changed lines 50-57 from:
[=*=]THINGS IíM NOT TOTALLY SURE ABOUT:
BY-PASS CAPACITOR. What does by-pass refer to?

''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]''

OUTPUT VOLTAGE: HMMMMÖ What exactly is the difference between Vo and delta Vo?

''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''
to:
Changed lines 17-18 from:
ThisWiki:/uploads/Reports/triangle.jpg
to:
ThisWiki:/uploads/Reports/triangle.gif
Changed lines 17-18 from:
[[Attach:triangle.gif]]
to:
ThisWiki:/uploads/Reports/triangle.jpg
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[[Attach:gptriangle.gif]]
to:
[[Attach:triangle.gif]]
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Changed line 15 from:
There is an Infrared Emitting LED, and an Infrared reciever, side by side. When an object is in front of the sensor, the reciever will sense the reflected IR light off of the object. Based on the angle of the reflection, distance is detected:
to:
There is an Infrared Emitting LED, and an Infrared reciever (which is a lens), side by side. Inside the unit is a CCD that recieves the light from the lens. When an object is in front of the sensor, the CCD will "see" the reflected IR light off from the object. Based on the angle of the reflection, distance is detected:
Added lines 13-17:
'''How it works'''
[[http://www.acroname.com/robotics/info/articles/sharp/sharp.html | A good intro to the sensor]]
There is an Infrared Emitting LED, and an Infrared reciever, side by side. When an object is in front of the sensor, the reciever will sense the reflected IR light off of the object. Based on the angle of the reflection, distance is detected:
[[Attach:gptriangle.gif]]
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[[Attach:gp.jpg]]
to:
ThisWiki:/uploads/Reports/gp.jpg
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[[Attach:gp2d120.jpg]]
to:
[[Attach:gp.jpg]]
Deleted line 9:
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ThisWiki:/uploads/Reports/gp2d120.jpg
to:
[[Attach:gp2d120.jpg]]

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[[Attach:gp2d120.jpg]]
to:
ThisWiki:/uploads/Reports/gp2d120.jpg
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[[Attach:gp2d120.jpg]]
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[[http://acroname.com/robotics/parts/R146-GP2D120.html]]\\
''this is a useful page. But a link to the original Sharp datasheet would be helpful as well. -[[~tigoe]]''
to:
[[http://acroname.com/robotics/parts/R146-GP2D120.html |Acroname's page]] on the Sharp GP2D120\\
''this is a useful page. But a link to the original [[http://www.datasheetarchive.com/semiconductors/download.php?Datasheet=815287 |Sharp datasheet]] would be helpful as well. -[[~tigoe]]''
Changed lines 23-27 from:
'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor,
you will get reliable readings. The output curve is non-linear; the closer you get, the more
the voltage increases per distance increment. However, when you get too close to the sensor,
the output voltage drops suddenly, and past that point, the output values are not reliable.
to:
'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor, you will get reliable readings. The output curve is non-linear; the closer you get, the more the voltage increases per distance increment. However, when you get too close to the sensor, the output voltage drops suddenly, and past that point, the output values are not reliable.
Changed lines 34-37 from:
and make sure it doesnít add up to more than the amounf of current your voltage regulator can supply (e.g. 1000mA for a
7805 5V regulator).
to:
and make sure it doesnít add up to more than the amounf of current your voltage regulator can
supply (e.g. 1000mA for a 7805 5V regulator).
Changed lines 44-46 from:
''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply.
They're usually placed as close to the sensor as possible. -[[~tigoe]]''
to:
''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply. They're usually placed as close to the sensor as possible. -[[~tigoe]]''
Changed lines 48-49 from:
''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range,
the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''
to:
''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range, the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''
Changed lines 2-3 from:
[[http://acroname.com/robotics/parts/R146-GP2D120.html]]
to:
[[http://acroname.com/robotics/parts/R146-GP2D120.html]]\\
''this is a useful page. But a link to the original Sharp datasheet would be helpful as well. -[[~tigoe]]''
Added lines 48-50:

''delta Vo refers to the voltage range, as it corresponds to the distance range. For example, for a 4-30cm range,
the output voltage range is 1.95 - 2.25 volts. -[[~tigoe]]''
Changed lines 16-28 from:
'''Measuring Distance (Range, or delta L)''': 4 cm - 30 cm

'''Supply Voltage (Vcc)''': Happy: 4.5 V Ė 5.5 V (Unhappy: Min Ė0.3 V, Max 7 V)

'''Output terminal voltage (Vo)''': Min 0.25 V, Typical 0.4 V, Max 0.55 V

'''Output voltage difference (delta Vo)''': Min 1.75 V, Typical 2.0 V, Max 2.25 V

'''The average supply current (Icc'''): Typical 33 mA, Max 50 mA



Measuring
Distance Explained: As long as you donít put objects closer than 4cm to the sensor,
to:
* '''Measuring Distance (Range, or delta L)''': 4 cm - 30 cm
* '''Supply Voltage (Vcc)''': Happy: 4.5 V Ė 5.5 V (Unhappy: Min Ė0.3 V, Max 7 V)
* '''Output terminal voltage (Vo)''': Min 0.25 V, Typical 0.4 V, Max 0.55 V
* '''Output voltage difference (delta Vo)''': Min 1.75 V, Typical 2.0 V, Max 2.25 V
* '''The average supply current (Icc'''): Typical 33 mA, Max 50 mA

'''Measuring Distance Explained:''' As long as you donít put objects closer than 4cm to the sensor,
Changed lines 27-28 from:
Supply Voltage (Vcc) Explained: This sensor is happiest when itís getting 4.5 Ė 5.5 V!
to:
''a graph of the range, and a diagram of the sensor might help here -[[~tigoe]]''

'''Supply Voltage (Vcc) Explained:'''
This sensor is happiest when itís getting 4.5 Ė 5.5 V!
Changed line 33 from:
Average Supply Current Explained: The Max current is what you would want to keep in
to:
'''Average Supply Current Explained:''' The Max current is what you would want to keep in
Changed lines 36-38 from:
and make sure it doesnít add up to more than 1000mA.
to:
and make sure it doesnít add up to more than the amounf of current your voltage regulator can supply (e.g. 1000mA for a
7805 5V regulator)
.
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''bypass capacitors are decoupling capacitors. They smooth out any dips and spikes in the sensor's power supply.
They're usually placed as close to the sensor as possible. -[[~tigoe]]''
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Original report: [[~pf372 | Paul Feder]]
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Supply Voltage (Vcc) Explained: This sensor is happiest when itís getting 4.5 Ė 5 V!
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Supply Voltage (Vcc) Explained: This sensor is happiest when itís getting 4.5 Ė 5.5 V!
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[[http://acroname.com/robotics/parts/R146-GP2D120.html]]
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*THINGS IíM NOT TOTALLY SURE ABOUT:
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[=*=]THINGS IíM NOT TOTALLY SURE ABOUT:
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'''The Sharp GP2D120'''

This is an Infrared (IR) sensor that detects changes in distance to an object
and outputs an analog voltage corresponding to how close or far away the object is to the sensor.
It is almost identical to the GP2D12, only the GP2D120 has a shorter range.

The connections are pretty simple. There are three wires: Power (Vcc), Ground (GND), and Output (Vo).
In order to keep the circuit happy, you should put a by-pass capacitor * of 10uF between Vcc and GND near the detector.
Et Voila!

Here are the Min/ Typ/ Max ratings when using a white piece of paper as the object the IR sensor is sensing.

'''Measuring Distance (Range, or delta L)''': 4 cm - 30 cm

'''Supply Voltage (Vcc)''': Happy: 4.5 V Ė 5.5 V (Unhappy: Min Ė0.3 V, Max 7 V)

'''Output terminal voltage (Vo)''': Min 0.25 V, Typical 0.4 V, Max 0.55 V

'''Output voltage difference (delta Vo)''': Min 1.75 V, Typical 2.0 V, Max 2.25 V

'''The average supply current (Icc'''): Typical 33 mA, Max 50 mA



Measuring Distance Explained: As long as you donít put objects closer than 4cm to the sensor,
you will get reliable readings. The output curve is non-linear; the closer you get, the more
the voltage increases per distance increment. However, when you get too close to the sensor,
the output voltage drops suddenly, and past that point, the output values are not reliable.

Supply Voltage (Vcc) Explained: This sensor is happiest when itís getting 4.5 Ė 5 V!

Output Voltage*

Average Supply Current Explained: The Max current is what you would want to keep in
mind if you have a lot of other electronics hooked up to the breadboard.
You would want to find the sum of all the Max current values of all your electronics
and make sure it doesnít add up to more than 1000mA.


*THINGS IíM NOT TOTALLY SURE ABOUT:
BY-PASS CAPACITOR. What does by-pass refer to?
OUTPUT VOLTAGE: HMMMMÖ What exactly is the difference between Vo and delta Vo?