Speaking aid for dumb - a simple project

ABSTRACT

      Speaking aid for dumb convert the gestures used by the dumb persons to sound. When a dumb person communicates using gestures, corresponding sounds will be heard through speaker. This will help the dumb people communicate with normal people who do not understand their gestures. LED-LDR networks are used for sensing the gestures. A flexible tube is placed between LED and LDR for passing the light. The LED-LDR network is placed on a glove worn by the dumb person. According to the finger bending, LDR resistance varies. The output of the sensor is converted to voltage and interfaced to   a LABVIEW through Arduino. The corresponding prerecorded sounds are played through loud speakers. This work produced sound for the gestures for the numbers 0 to 9 for which it was designed.

INTRODUCTION

      The dumb people can’t communicate with normal people effectively because they use gestures for communication and this method is not familiar for normal people. Speaking aid for dumb helps to reduce this difficulty by producing sound for each gestures.

The gestures are sensed using LED-LDR network placed on the glove worn by dump person. The voltage output produced is amplified and is interfaced to LABVIEW through Arduino. Prerecorded sounds are played through loud speakers according to finger movement. This work focuses on the production of sound output for the gestures of digits.

BLOCK DIAGRAM

       The block diagram for the Speaking Aid for Dump is given below. It contains mainly four parts. 

speaking aid for dumb: block diagram

HAND

      Speaking aid converts the hand gestures to sounds especially 0 to 9. So we have to sense the hand gestures. And the way of expressing this numbers is as follows.

gestures for numbers 0 to 9

LED-LDR NETWORK (SENSOR)

      The LED-LDR network is used to sense the hand movement. This sensor network has uses a combination of  LED and LDR. The LED produces light and this light is sensed using the LDR.

Here the LEDs are used as light source in the sensor. White LEDs are placed in black coated tube, so that any wave does not penetrate to outside. When a 3V supply is provided, it will glow with high intensity

light dependent resistor (LDR) is a resistor whose resistance decreases with increasing incident light intensity

LED-LDR sensor

the above shows the sensor. LED and LDR are placed on either side of a tube covered by a black coating. LED is connected with a power supply of 3v. Intensity of light is inversely proportional to resistance of LDR. So as the tube becomes straight, the resistance of LDR decreases

LABVIEW ARDUINO INTERFACING:

      Setting up the LabVIEW Interface for Arduino is a six step process that you will only need to complete once. Follow the instructions below to start creating applications with the LabVIEW Interface for Arduino.

 1. Install LabVIEW

  

2. Install the NI-VISA drivers

3. Install JKI VI Package Manager (VIPM) Community Edition.

4. Install the LabVIEW Interface for Arduino.

5. Connect your Arduino to your PC as described.

6. Load the LabVIEW Interface for Arduino Firmware onto your Arduino.

CIRCUIT DIAGRAM

circuit diagram

So the circuit can be divided into  two parts:

    Wheatstone bridge

    Differential amplifier

The output voltage of the differential amplifier is Rf/R1(V2-V1).

The voltage obtained at the nodes of wheatstone bridge are:

• When finger kept straight, V2-V1 = 0.18V
• When finger is bent,          V2-V1 = 0.42V 

We have to convert this voltage range into 0 to 5V, analog input range of Arduino uno. So we designed a differential amplifier with a gain of 10. Hence the output of amplifier is either 1.8V or 4.2V.

So,              

                 Rf/R1=10

Here,        

                 Rf = 10K         &     R1 = 1K

LABVIEW PROGRAMMING

The sensor output voltage obtained is given to LABVIEW through Arduino. This analog voltage is compared to a reference voltage and a Boolean logic is used to select the appropriate sound file. The Boolean logic is designed based on the table given below:

Boolean logic for selecting sound file

ALGORITHM:

• Arduino reads the analog input.
• Compare it with a reference voltage,3V.
• If voltage is less than 3V,finger is straight, it is assumed as logic 0.
• If voltage is greater than 3V,finger is bent, it is assumed as logic 1.
• Now deduce the digital expression using logic gates.

1        ZERO = A0.A1.A2.A3.A4

2        ONE = A0.A1’.A2.A3.A4

3        TWO = A0.A1’.A2’.A3.A4

4        THREE = A0’.A1’.A2’.A3.A4

5        FOUR = A0.A1’.A2’.A3’.A4’

6        FIVE = A0’.A1’.A2’.A3’.A4’

7        SIX = A0.A1’.A2’.A3’.A4

8        SEVEN = A0.A1’.A2’.A3.A4’

9        EIGHT = A0.A1’.A2.A3’.A4’

    10    NINE = A0.A1.A2’.A3’.A4’

block diagram (labview)

front panel

PROCEDURE

• Give power supply to the circuit
• Connect arduino to LABVIEW
• Wear the glove
• Run the program
• Move the fingers according to the  numbers

speaking aid for dumb- designed by me