hand gesture remote control

8/6/2019 Hand Gesture Remote Control

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Justin Johnson, Joe Pommier, Mike Wang


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` A consumer device that just works

` Consists of a single box that can be plugged in,easily configured for your television, and will work

reliably indefinitely` Works with already functional infrared remote

control receivers built into most television sets

` Uses infrared light to track movements


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` Encompassescamera, clockgeneration, and logic

level translationcircuitry

` Camera is a Pixartinfrared sensitive

digital camera withonboard digital signalprocessing


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` Use a crystal oscillator and double inverters tocreate 25MHz clock

` Using an LTC4301 I2C bus buffer chip, perform

logic level translations between +5V on theArduino side and +3.3V on the camera side

` With properly written software, communicationwith the camera was successful


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` Laid out circuit in Eagle and ordered a PCB

` About to solder on the camera and realized thepins were reversed

` Had to re-layout the PCB` Tested the clock circuit by plotting the waveform

on an oscilloscope While the clock wasnt close to a perfect square wave,

the rise and fall was fast enough (


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` Simply an infrared LED modulated at 36KHz

` Turned on and off 67 times for various times,specified in milliseconds

` Tested by writing a simple program to loop throughvarious remote control codes that were recorded

` Verified that TV reacted in the way expected


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` Infrared 20x10 LEDsfor releasing Infraredlight flood

` 1.7 V, 50mADCvoltage and currentthrough each LED


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` PowerSupply: a 36V AC/DC Voltage Converter(Input 110V AC, Output 36V DC)

` Constant current source is made of 10 LM317

Voltage Regulator and 10 100ohm resistors` Each LM317 with a 100ohm resistor with it is

connected in series with each row of LEDs

` Input Voltage for each row of LEDs: ~36V

` Input Current for each row of LEDs: 50~55mA` System Power Consumption: ~20 Watts


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` Initially we used Current Mirrors for makingconstant current, including 11 NPN BJTtransistors: successfully simulated,inconsistent at proto-type performance

` We upgraded Current Mirrors to Wilson

Current Mirrors by adding extra transistors tothe mirrors in order to stabilize the outputs:successful at supporting a single row of LEDs,unsuccessful at supporting multi rows of LEDs

` We also thought of using Op-Amps, but its notcost-effective and it is hard to get Op-Amps

with 36V tolerance.


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` Why we chose LM317 circuit plan:*Initially we chose Current Mirrors for loweringmanufacturing cost, but neither Wilson CurrentMirrors norOp-Amp costs less than LM317.

*All other plans result over-heating problems forresistors as well as large power consumption


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` Current Measurements: our finaldesign shows that there is a currentbetween 52.1~53.1 mA DC currentthrough each row of LEDs with

consistent performance` LEDs have been on duty without a

single failure for more than 45minutes of testing since thecompletion of the LED Array.

` Temperature of resistors in the currentsource circuit has been significantlylowered.

Row# Current (mA)

1 52.3

2 52.5

3 52.5

4 52.1

5 53.1

6 52.6

7 52.8

8 52.9

9 52.4

10 52.8


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` Initializes and samplescoordinate data fromthe Pixart camera viaI2C.

` Stores and operates onthe data received fromthe camera.

` Upon successful

recognition of agesture, outputs thecorresponding signal tothe television.


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` At first, wanted to have a sliding window ofreceived coordinates with constant comparisons toan accepted gesture for all four of the availablepoints given by the camera.

` Due to the severe limitations of ourmicrocontroller, the gesture software had to betoned down.

` We decided to operate only on most prominent

received point, and only detect the mostrudimentary (straight line) gestures.


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` The recognizing algorithm stores (x,y) data into arrays.Upon seeing blank frames, or after one second datastorage, it sends this data to a function that looks for agesture.

` To find a gesture, we first find the distance the pointmoved in both the x and y directions. We then checkdirection of movement, and distance of movement todetermine whether or not we can consider the data tocontain a gesture.

` If a gesture is detected, we send a series of pulses tothe IR transmitter to control the television.


16/22

` The first version of the software that we used to testsimply relayed what the camera saw to a computerdesktop. This was used extensively in debugging thelater code and the hardware.

` The final software had to go through a coupleiterations as we did not know the capacity of theArduino, and so we had to compensate for a lowmemory, low processor situation.

` The software was then calibrated for minimum pixelmovement to help filter out small movements asgestures.


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` Once all the components were assembled, weaddressed fine-tuning issues

` We were unable to get enough infrared light to be

reflected off our fingers` We tried using aluminum foil to reflect more light

This provided more reflection, but the useful range waslimited to about one foot

A

ssembled a small LED

pen in order to provide a singlepoint source of light for the infrared camera


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` With this point source of light, we were able toexceed 6 feet of range

` Having overhead lights on interfered only if the

lights were in the line of sight


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To find better reflection material in order toincrease remote range and efficiency

To use stronger and fewer infrared LEDs for betterperformance and lowering manufacturing cost

To use more advanced cameras to increase

gesture detection ability


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` Low Cost Analysis:

Proposed Manufacturing Cost:Camera: $3~5

Microcontroller: $10~15

LM317 x10: $3~5

LEDs and other minorcomponents: < $5

Total: < $30

Part Quantity Cost per unit Total CostCamera/Wiimote 1 $40.00 $40.00

IR LEDs-880nm 250 $0.16 $40.25

IR LED-940nm 1 $0.11 $0.11

3300uF capacitor 1 $4.24 $4.24

Diode-1N4001 8 $0.04 $0.34

100uF capacitor 1 $0.20 $0.20

Power Transformer (120VAC->36VAC) 1 $13.09 $13.09

Zener Diode-36V 1 $0.28 $0.28

2W resistors 14 $0.05 $0.74

Circuit Boards 2 $3.00 $6.00

Microcontroller-Arduino 1 $30.00 $30.00

100pF capacitor 2 $0.20 $0.40

Hex Inverter 1 $0.10 $0.10

Crystal Oscillator 1 $5.71 $5.71

Consumable Materials 1 $3.00 $3.00

Total $144.47

Prototype Cost: $144.47Development cost for Natal: ???

Whats the price you are expecting from our potentialcompetitor Natal? $100? $200? or $300?


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` Fields which this low-cost gesture remote systemcan be applied at:

Basic TV Remote

ProjectorActive Video Game Devices

ConfidentialAccess Devices

Dancing and OtherEntertainment Devices


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THANK YOU FOR COMING TO OURPRESENTATION!

hand gesture remote control

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