Presentation Discrete Distributed Sensor Matrix 2009 MohammadTahaBintahir

8/17/2019 Presentation Discrete Distributed Sensor Matrix 2009 MohammadTahaBintahir

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By

Mohammad Bintahir

Gunjan Patel


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• Multi-touch and multi-modal technologies have existedsince 80’s

• Only recently has the technology been cost efficient androbust enough to allow full implementation of environments

where these technologies can be utilized, cheaply andeffectively.

• The recent developments of multi-touch technology such asthe Apple iPhone, Microsoft Thingsight and Jeff Han’sTouch wall to name a few examples, show the increasingneed, demand, use and popularity of these devices.

• The combination of these events and the needs for a trulyversatile multi-touch and multi-modal hardware hasprompted the development of this project.


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The objective of this project is to design and prototype animplementation of a hardware device that will allow for thedetection of multi-modal inputs. The device will allow for multi-touch and multi-user interaction with a defined focus to create astable modular hardware prototype based on a discretedistributed sensor array.


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• Implement a method of expanding the digital workflowenvironment in such a way that natural intuitive humaninteractions can be developed and implemented to facilitatecollaboration of multiple users and workflows togetherseamlessly.

• The user can manipulate, share and transfer digital content inways not associated with the use of traditional personalcomputers.

• Touch-based interaction offers several advantages over currentWIMP based interfaces, especially when it comes to the use ofphysical objects or widgets in interactive scenarios.

• Traditional multi-point and multi-user collaboration systemstypically rely on projectionsand cameras.

• While camera based gesture recognition methods are mostcommonly used, they often suffer from integral flaws such aslighting conditions, occlusion, and field of view


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This capstone introduces a new sensing architecture, which willfacilitate new and emerging interactive models, it is based onDiscrete Distributed Sensors.

The method of sensing proposed will accurately track the position

of the user’s inputs in 2-Dimentional space and will be able tocalculate the pressure of the input.

In its elemental design it will be constructed using a basic voltagedivider circuit shown below.


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Below is Level 0 of the Discrete Distributed Sensor Matrix, whereIR signal as input with power of 5V DC and output is a twodimensional matrix containing IR intensity data across themodule.

Discrete Distributed Sensor

Matrix

IR Input Signal

Power, 5V DC

Sensor Data Output Signal


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This is Level 1 cascaded architecture used to detect multi-modal inputsbased on IR signal.

The First Stage – 16x8 array of IR Sensor s are used as the Input sourcesthat provide a relative Vout that based off the level of IR intensity that thesensor can detect.

Second Stage – is the Analog to Digital conversion step that converts theSensor Data Output Signal into a Quantized Data output signal.

The Final Stage – is where the data is processed and a digitized signal issent to the computer to allow for blob analysis.


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This is an overview of Level 2 design of how the DiscreteDistributed sensor matrix prototype looks like.

ADC

ADC

ADC

ADC

ADC

ADC

ADC

ADC

ADC

ADC

ADC

ADC

ADC

ADC

Mi c r o c on t r ol l er Uni t

16 x 8 Infrared Sensors

SPIUSB


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SPI

Master

SCLK

MOSI

SS

MISO1

MISO2

MISO3

SCLK

MOSI

SS

MISO

SCLK

MOSI

SSMISO

SCLK

MOSI

SS

MISO

SPI

Slave

SPISlave

SPI

Slave

SPI BUS Design

Figure below represents the SPI BUS Design that allows for

communication between the ADC and MCU – SPI Masterrepresents the MCU and SPI Slave represents the ADC.


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This prototype consist of 32 discrete distributed sensor matrix form, and it wastested successfully.


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Final design consists of same essential voltagedivider circuit shown previously in 16 x 8 sensorsarrays.

The total prototype will consist of 128 sensors

Parallel data processing and acquisitions allows forfaster and more responsive detection of inputs

Prototype is designed in a 16:9 format that willallow easy scalability on traditional LCD screens.


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Prototype: Sensor Schematic


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Prototype: MCU Motherboard Schematic


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• This is the final design of 16x8 discrete distributes sensor matrix, where totalof 128 IR sensors are used. It is two board design and its currently mounted

withmicrocontrollerunit.


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This is the front view of 128 IR sensorssoldered on PCB.


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This is 2nd PCB, where ADC and capacitors aresoldered.


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Software consist of three critical components:

1. Microcontroller code

2. Blob analysis and tracking on the computer

3. Implementing interface design


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Essentially the microcontroller code isresponsible for polling each individual sensorand extrapolating IR intensity from input

source. We do this by implementing unique row and

column address where at each pass themicrocontroller sets high each column and

polls each sensor by accessing the channels 1 to8 of the ADC to obtain 2-D array of 12-bitsensor data.


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When the first frame of the data has beencaptured in this 2-D array, it is used as a staticreference for threshold calculations. Where

each subsequent frame is compared to this firstframe. The resulting 2-D array is ourcompensated sensor data.

This compensated sensor data is than

transmitted via USB to computer.


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The resulting data received from the MCU isthan instructed into a low resolution, highframe rate video feed.

This video feed is analyzed by using computervision techniques.

The technique, that was implemented is basedof the principle of growing regions. Where eachsensor value above predefined user controlledthreshold is noted and its position is recorded.


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These sensor values are than grouped ifadjacent sensor values are also above thespecified threshold level.

Each of these groups is than assigned an IDand its XY co-ordinates are noted.

The resulting identification is now tracked andcan be utilized for third party interfacingapplications.


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The tracked IDs and positions can now be usedto develop applications such as this:


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Have a nice Day…

Documents

Presentation Discrete Distributed Sensor Matrix 2009 MohammadTahaBintahir