iDine A Camera based Multi-touch Dining table

Tejas D Kulkarni

Abhisheyk Gaur

Himanshu Raghav

Ankur Mishra

OutlineOutline

• Project overview Project overview • Project-specific success criteriaProject-specific success criteria• Block diagramBlock diagram• Component selection rationaleComponent selection rationale• Packaging designPackaging design• Schematic and theory of operationSchematic and theory of operation• PCB layoutPCB layout• Software design / development statusSoftware design / development status• Project completion timelineProject completion timeline• Questions / discussionQuestions / discussion

Project OverviewProject Overview

A multi-touch interface for a dining table which supports menu browsing, order placement, music and / or game selection.

A handheld device which acts as a centralized control for an array of multi-touch enabled dining tables.

Wireless medium of exchange between the controlling handheld device and the multi-touch enabled table

Change / update of menu supported through a SD Card interface

An ability to wirelessly exchange information between the Intel Atom and External Managing device via Bluetooth interface

An ability to read/write data such as menu items, items ordered, statistics, feedback and other preferences from a SD card interface

An ability to display information obtained from the touch interface such as the food item ordered, billing information and other data on a Graphical LCD on the External Managing Device

An ability to detect and process multiple fingers and gestures on the touch table via a Intel Atom board

An ability to charge the battery of the External Managing Device and monitor its status on the LCD

Success Criteria

BLOCK DIAGRAM

Component selection rationale

• Microcontroller: PIC24FJ128GA010

• C Compiler Optimized Instruction Set 

• Great debugging support (development board available)

• Satisfies our peripherals requirements: 2 SCI and 1 SPI

• Can handle medium to high computations (required for display on graphical LCD)

• Has sufficient memory for graphics and other drivers (128 KB flash and 8 KB RAM)

Component selection rationale

• Bluetooth Modem: BlueSMiRF Gold

• Required for consistent communication with the Atom board 

• Provides flexible configurations (via command set) over wireless transmission

• Low power consumption (25mA Avg. current draw)

• Small size (suited for a handheld device)

• SD/MMC Breakout Board

• Required for memory 

• Easily configurable

• Supports push-push type socket for SD Card

Packaging Design

• EMD will be compromised of 5” by 3” by 1” boxEMD will be compromised of 5” by 3” by 1” box– A 2.4” graphical LCD is mounted on of the faces of this A 2.4” graphical LCD is mounted on of the faces of this

boxbox

– Three color LED's to indicate the mode of operation of Three color LED's to indicate the mode of operation of EMDEMD

– A SD card slot on of the sideA SD card slot on of the side

– An outlet to charge the Li-Ion batteryAn outlet to charge the Li-Ion battery

• PCB will be compromised of size 4” by 2.5”PCB will be compromised of size 4” by 2.5”

Packaging Design : Front View

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3

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Packaging Design : Reverse View

Theory of Operation and Schematic

Theory of operation• Microcontroller : PIC24FJ128GA010Microcontroller : PIC24FJ128GA010

– Operating voltage is 3.3 V at 32 MHzOperating voltage is 3.3 V at 32 MHz

– Drives Bluetooth (UART), SD Card Drives Bluetooth (UART), SD Card (SPI), Coulomb counter (GPIO) and (SPI), Coulomb counter (GPIO) and Graphical LCD (UART)Graphical LCD (UART)

– PCB provides pinouts for programming PCB provides pinouts for programming the microcontroller (3 pins – serial clock, the microcontroller (3 pins – serial clock, serial data and program enable)serial data and program enable)

Theory of operation

• Power and Battery managementPower and Battery management– A 7.2 V rechargeable Li-Ion batteryA 7.2 V rechargeable Li-Ion battery

– LTC-1731 IC charger circuit for charging LTC-1731 IC charger circuit for charging via a AC/DC adapter (9V, 2 A) via a AC/DC adapter (9V, 2 A)

– LTC-4150 Battery coulomb counter LTC-4150 Battery coulomb counter which generates interrupts as a means to which generates interrupts as a means to measure battery lifemeasure battery life

– A 5V and 3.3V voltage (1 A current) A 5V and 3.3V voltage (1 A current) regulators to power the main circuitregulators to power the main circuit

Theory of operation• Graphical LCD (DX 160)Graphical LCD (DX 160)

– Operates at 5 V and requires 45mA to Operates at 5 V and requires 45mA to drive the LCD at 100% backlightdrive the LCD at 100% backlight

– LTC-1129 voltage regulator to translate LTC-1129 voltage regulator to translate TTL logic between 5V and 3.3V to TTL logic between 5V and 3.3V to communicate with the microcontrollercommunicate with the microcontroller

– Operates at 115k baudrate, no parity Operates at 115k baudrate, no parity and 1 stop bitand 1 stop bit

Theory of operation• SD CardSD Card

– Operating at 3.3V in SPI Mode (16 MHz)Operating at 3.3V in SPI Mode (16 MHz)

• Bluetooth (BlueSmirf module)Bluetooth (BlueSmirf module)– Operating at 5V at 2.5 GHzOperating at 5V at 2.5 GHz

– An Intersil CD401 low-to-high voltage An Intersil CD401 low-to-high voltage shifter to interface the module with the shifter to interface the module with the microcontrollermicrocontroller

– Runs at 115k baudrate, no parity and 1 Runs at 115k baudrate, no parity and 1 stop bitstop bit

PCB Layout

PCB Layout

Considerations:Considerations:-Two major section – Microcontrollers (Peripherals) and Power -Two major section – Microcontrollers (Peripherals) and Power

supply system.supply system.

-Separation due to Analog Circuit Noise.-Separation due to Analog Circuit Noise.

-Separate GND planes tied together-Separate GND planes tied together

-Trace width of 40 mils for power circuit, 12 mils for digital circuit.-Trace width of 40 mils for power circuit, 12 mils for digital circuit.

Digital Section:Digital Section:PIC24 Microcontroller, Bluetooth module, SD-Card module,PIC24 Microcontroller, Bluetooth module, SD-Card module,

LTC4150 Coulomb counter, LCD DX-160, Push buttons. LTC4150 Coulomb counter, LCD DX-160, Push buttons.

PCB LayoutAnalog Section:Analog Section:LT1510 battery charger, two DE-SW0XX switching voltageLT1510 battery charger, two DE-SW0XX switching voltage

regulators, input from 9V wall adaptor.regulators, input from 9V wall adaptor.

Microcontroller Layout considerations:Microcontroller Layout considerations:-4 decoupling capacitors for power supply.-4 decoupling capacitors for power supply.

-Placed on reverse side of PCB to save space.-Placed on reverse side of PCB to save space.

-GND plane to provide easy access to GND signals for these -GND plane to provide easy access to GND signals for these

capacitorscapacitors

-Headers placed close to MCU for debugging.-Headers placed close to MCU for debugging.-Peripherals laid out on PCB so that they are closet to respective -Peripherals laid out on PCB so that they are closet to respective

pins on microcontroller to avoid crossing. pins on microcontroller to avoid crossing.

PCB LayoutPower supply Layout considerations:Power supply Layout considerations:

-Power provided using 7.2 Li-ion rechargeable battery-Power provided using 7.2 Li-ion rechargeable battery-9V DC input from wall adaptor for recharging and direct supply-9V DC input from wall adaptor for recharging and direct supply-100 mils trace for 9V input. -100 mils trace for 9V input. -Use of bulk decoupling capacitor to remove noise-Use of bulk decoupling capacitor to remove noise-LT1510 charger consists of high freq. circulating GND path, -LT1510 charger consists of high freq. circulating GND path,

hence GND plane would be used beneath charger to keep hence GND plane would be used beneath charger to keep traces to GND minimumtraces to GND minimum

-Inductor required for high freq. circuit (no GND plane beneath it)-Inductor required for high freq. circuit (no GND plane beneath it)-Two DE-SW0XX voltage regulator. Would be kept away to -Two DE-SW0XX voltage regulator. Would be kept away to

reduce RF noise they might cause.reduce RF noise they might cause.-GND plane would act as heat sink. External heat sink might be -GND plane would act as heat sink. External heat sink might be

added if required later on.added if required later on.

Top Level

Microcontroller

Power Circuit

Software Design

• Multi-touch table SoftwareMulti-touch table Software– A Kalman filter to predict the movement A Kalman filter to predict the movement

of blobs in video frames with Background of blobs in video frames with Background subtractionsubtraction

Here xk = new positionHere xk = new position

Vuk = change due to velocityVuk = change due to velocity

yk = position with noise toleranceyk = position with noise tolerance

Software Design

• ““Time To Live” learning algorithm to quickly Time To Live” learning algorithm to quickly diminish stationary objects and other diminish stationary objects and other background objectsbackground objects

Stationary blobs TTL= 4 sec

Touch Table Touch Table

Software Design

• Bluetooth Module – Able to interface it with the Bluetooth Module – Able to interface it with the Intel Atom board (receive and send data at Intel Atom board (receive and send data at 115k baud)115k baud)

Software Design

• Graphical LCD – Able to draw ASCII characters Graphical LCD – Able to draw ASCII characters and developed an API to draw custom shapes and developed an API to draw custom shapes such as : Circles, lines and rectanglessuch as : Circles, lines and rectangles

Software Design

• SD Card: An API to read and write data to SD SD Card: An API to read and write data to SD Card. Until now, the read function and Card. Until now, the read function and initializing functions work flawlessly. FAT16 API initializing functions work flawlessly. FAT16 API in progress.in progress.

Project completion timeline TASK TIMELINE

Final PCB layout 11th March, 2010

Initial circuit testing (breadboard) 10th March, 2010

Bluetooth protocol 24th March, 2010

SD Card API 29th March, 2010

Graphical LCD drivers 31st March, 2010

Multi-touch table hardware 25th March, 2010

Multi-touch table software testing 1st April, 2010

PCB testing 10th April, 2010

Packaging 1st April, 2010

Question ?