iDine A Camera based Multi-touch Dining table Tejas D Kulkarni Abhisheyk Gaur Himanshu Raghav Ankur Mishra

Outline Project overview Project overview Project-specific success criteria Project-specific success criteria Block diagram Block diagram Component selection rationale Component selection rationale Packaging design Packaging design Schematic and theory of operation Schematic and theory of operation PCB layout PCB layout Software design / development status Software design / development status Project completion timeline Project completion timeline Questions / discussion Questions / discussion

Project 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” box EMD will be compromised of 5” by 3” by 1” box – A 2.4” graphical LCD is mounted on of the faces of this box – Three color LED's to indicate the mode of operation of EMD – A SD card slot on of the side – An 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 5 3 1

Packaging Design : Reverse View

Theory of Operation and Schematic

Theory of operation Microcontroller : PIC24FJ128GA010 Microcontroller : PIC24FJ128GA010 – Operating voltage is 3.3 V at 32 MHz – Drives Bluetooth (UART), SD Card (SPI), Coulomb counter (GPIO) and Graphical LCD (UART) – PCB provides pinouts for programming the microcontroller (3 pins – serial clock, serial data and program enable)

Theory of operation Power and Battery management Power and Battery management – A 7.2 V rechargeable Li-Ion battery – LTC-1731 IC charger circuit for charging via a AC/DC adapter (9V, 2 A) – LTC-4150 Battery coulomb counter which generates interrupts as a means to measure battery life – A 5V and 3.3V voltage (1 A current) regulators to power the main circuit

Theory of operation Graphical LCD (DX 160) Graphical LCD (DX 160) – Operates at 5 V and requires 45mA to drive the LCD at 100% backlight – LTC-1129 voltage regulator to translate TTL logic between 5V and 3.3V to communicate with the microcontroller – Operates at 115k baudrate, no parity and 1 stop bit

Theory of operation SD Card SD Card – Operating at 3.3V in SPI Mode (16 MHz) Bluetooth (BlueSmirf module) Bluetooth (BlueSmirf module) – Operating at 5V at 2.5 GHz – An Intersil CD401 low-to-high voltage shifter to interface the module with the microcontroller – Runs at 115k baudrate, no parity and 1 stop bit

PCB Layout

Considerations: -Two major section – Microcontrollers (Peripherals) and Power supply system. -Separation due to Analog Circuit Noise. -Separate GND planes tied together -Trace width of 40 mils for power circuit, 12 mils for digital circuit. Digital Section: PIC24 Microcontroller, Bluetooth module, SD-Card module, LTC4150 Coulomb counter, LCD DX-160, Push buttons.

PCB Layout Analog Section: LT1510 battery charger, two DE-SW0XX switching voltage regulators, input from 9V wall adaptor. Microcontroller Layout considerations: -4 decoupling capacitors for power supply. -Placed on reverse side of PCB to save space. -GND plane to provide easy access to GND signals for these capacitors -Headers placed close to MCU for debugging. -Peripherals laid out on PCB so that they are closet to respective pins on microcontroller to avoid crossing.

PCB Layout Power supply Layout considerations: -Power provided using 7.2 Li-ion rechargeable battery -9V DC input from wall adaptor for recharging and direct supply -100 mils trace for 9V input. -Use of bulk decoupling capacitor to remove noise -LT1510 charger consists of high freq. circulating GND path, hence GND plane would be used beneath charger to keep traces to GND minimum -Inductor required for high freq. circuit (no GND plane beneath it) -Two DE-SW0XX voltage regulator. Would be kept away to reduce RF noise they might cause. -GND plane would act as heat sink. External heat sink might be added if required later on.

Top Level

Microcontroller

Power Circuit

Software Design Multi-touch table Software Multi-touch table Software – A Kalman filter to predict the movement of blobs in video frames with Background subtraction Here xk = new position Vuk = change due to velocity Vuk = change due to velocity yk = position with noise tolerance yk = position with noise tolerance

Software Design “Time To Live” learning algorithm to quickly diminish stationary objects and other background objects “Time To Live” learning algorithm to quickly diminish stationary objects and other background objects Stationary blobsTTL= 4 sec Touch Table

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

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

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

Project completion timeline TASK TIMELINE Final PCB layout 11 th March, 2010 Initial circuit testing (breadboard) 10 th March, 2010 Bluetooth protocol 24 th March, 2010 SD Card API 29 th March, 2010 Graphical LCD drivers 31 st March, 2010 Multi-touch table hardware 25 th March, 2010 Multi-touch table software testing 1 st April, 2010 PCB testing 10 th April, 2010 Packaging1 st April, 2010

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