daqProposal

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EE-321 DATA ACQUISITION & INTERFACINGP R O J E C T P R O P O S A L :

CONTINUUM FINGERBOARDTH E TOU C H SY N TH ESI ZER

ANUM AJMAL 2013-10-0156

M. HARIS USMANI 2013-10-0058

SHER HASSAN RAZA 2013-10-0029

MUHAMMAD FAHAD FAROOQ 2013-10-0049


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CONTINUUM FINGERBOARD 2

C ON T E N T S :

BLOCKDIAGRAM.PG. 3

AIMS ANDOBJECTIVES....... . . . . . . . . . . . .. . . . . . . . . . .PG. 4

TENTATIVEPROCEDURE............PG. 5

TENTATIVEALGORITHM...PG. 5

ADDITIONALFEATURES...PG. 6

WORKDISTRIBUTION ...PG. 7


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BLOCK DIAGRAM:

Analogue to Digital

Conversion of

Voltage Level

received

Algorithm gives x

and y

Sound generation of

the Note

corresponding to

the x- y coordinate

IR Transmitters

IR SENSORS

IR SENSORS

IR Transmitters

Sound Signal to

External Effect

Processor and

Amplifier


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AIMS & OBJECTIVES:

The Continuum is a relatively new musical instrument invented by Dr. Haken at the

EE Dept. of University of Illinois, USA. It is used for special effects in a wide genre of

music. It is radically different from a conventional keyboard, as the notes that are

produced are continuous in response (pitch, volume etc) and there are three-axes of

input rather than just two.

We aspire to create a Digital Replica of the Continuum that uses an IR Array (2D or

3D) to capture the musicians finger position and the Signal Generation Capabilities

of ATMEL Atmega16 to generate musical notes. We want to primarily focus on the

Input Device rather than the Audio Processing, as it more relevant to our course.

We aim to implement a 2D IR Array to be used as a Touch Screen for a DigitalSynthesizer

Our Priorities for the Design:1. Robustness and Accuracy for this Input Device2. Least Latency for Response: the Input Detection and Output Signal

Generation/Processing

3. Quality/Sample Rate of Audio Produced Additional Challenges/Bonus*:

1. Continuous Output in All Axes2. Multi-finger Detection3. 3-Axes Detection

*if time permits


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TENTATIVE PROCEDURE:

1) We will start by working on our IR sensors. We will experiment to find: Howthey can be used most effectively? Whats their LargestRange? How to get

better reception, using pulsed or continuous input signal? Maximumthreshold distance beyond which our IR sensors will not give as a useful

change in voltage?

2) After the efficient working of IR sensors has been established, we make asample 2x2 square to help us make a working algorithm. Analog Multiplexers

will be used to interface the IR sensors to the micro-controllers ADC Input.

3) Once the algorithm (a highly customized version of scan and multiplex) hasbeen made, it can be extended to any number of rows and columns we like.The limitation here being that we need to scan and detect the x and y

coordinates without a substantial delay or latency. We need to start sound

processing after we make the 2x2 algorithm because that will also eat up a lot

of processing power of the micro-controller and will also play a substantial

part in the delay. If not possible, we will have to use 2 microcontrollers.

On a totally separate subject once we have the x and y coordinates we can do

anything with them. That is that we can either make a continuum or we can make a

virtual keyboard/ touch screen anything.

4) Once the XY (or XYZ) positions are captured, we can focus on producing theaccurate frequencies for the notes. Our audio-part of the algorithm will use

the X-axis for the Pitch Calculation and Y-axis for the volume.

TENTATIVE ALGORITHM:

Input Device: our objective is to design an algorithm that will automatically adjust toignore IR Environmental Noise. There are two approaches:

1) The system takes some time to warm up and calibrate itseld. This means that

before the device can be used, it sets itself some noise level values. For example, we

just turned the device on. The device calculates the voltage received on every IR

sensor individually. And then uses that voltage as a benchmark for further


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calculations. This is done when the micro controller is reset or maybe set on an

external interrupt.

2) The second way is to repeat the above but do it every time the loop runs. This

maybe done by giving a square wave signal to the IR Emitters, and then sampling

the IR Sensors at a low and a high signal. Although this method is much moreaccurate, we have a limit on the speed and further discussion on the merits of each

technique can only be done once we have coded and checked it out.

Sound Generation:

A specific algorithm will be used to generate sin waves of the particular frequencies.

These frequencies will be converted to Analog and given out to the Effect Pedal and

Amplifier.

We plan to implement 14 x-axis levels (spanning from C4 to C#5), to allow us to play

a melody that fits in almost one octave.

ADDITIONAL FEATURES

1. Continuous Output in All Axes:Right now, we intend to quantize the regions on the screen and then play the

tunes corresponding to the respective regions. (Example: Swipping your

finger across plays Quantized Notes i.e. A, A#, B and so on like a Keyboad.)

If time permits, we will try to implement a continuous x-y calculation instead

of discrete x-y positions. This will enable us to implement a continuum

instrument in essence.


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2. Multi-finger Detection:Our basic model consists of the movement of one finger. If we get this done

perfectly, we will work on capturing multiple fingers moving on the screen at

the same time.

3. 3-Axes Detection:If time permits we shall extend this model to 3D and also try generating other

functionalities by detection of the x y z coordinates.

WORK DISTRIBUTION

Hardware

Design

Software

(Coding)

Algorithm

Design

Documentation

& Research

Anum Ajmal

M. Haris Usmani

Sher Hassan Raza

Muhammad Fahad

Farooq

Documents

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