Introduction: Sign Language Glove
The development of the devices that help the deaf and mute people to communicate with normal people began a long time ago. They find difficulties to express their thoughts or to convey their message to other people so that the researchers attempt different ways in order to produce a device that may give them a better quality of the life to work in basic situations. To achieve this, the system combines the use of a set of different modules, such as gesture recognition, sign language analysis and synthesis, speech analysis and synthesis, haptic, into an innovative multimodal interface available to disabled users. In the recent years, there is a rapid increase in the number of speech - disabled victims due to several reasons like by birth, oral diseases, accidents, etc… and need for the Electronic Assistive. This project is useful for the deaf and dumb, it can also be used for the (speechless) patients with half of their bodies paralyzed and who are not able to speak but are able to move their fingers. The project has been used Glove which will assist those people who are suffering from any kind of speech defect to communicate through their hand pressures. The glove will record hand press made by the user and then the glove will translate these press into visual form as well as in audio form. Demonstrated is the use of flex force sensors to detect the finger's presses.
· Flex Sensors
· Power Supply Circuitry
Step 1: UNDERSTAND THE SYSTEM DESIGN
An Embedded System is a combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to perform a specific function. An embedded system is a microcontroller-based, software driven, reliable, real-time control system, autonomous, or human or network interactive, operating on diverse physical variables and in diverse environments and sold into a competitive and cost conscious market.
An embedded system is not a computer system that is used primarily for processing, not a software system on PC or UNIX, not a traditional business or scientific application. High-end embedded & lower end embedded systems. High-end embedded system - Generally 32, 64 Bit Controllers used with OS. Examples Personal Digital Assistant and Mobile phones etc .Lower end embedded systems - Generally 8,16 Bit Controllers used with an minimal operating systems and hardware layout designed for the specific purpose. Examples Small controllers and devices in our everyday life like Washing Machine, Microwave Ovens, where they are embedded in.
Step 2: BLOCK DIAGRAM AND COLETING SYSTEM COMPONENTS
- Raspberry Pi
- Flex Sensors
- Power Supply Circuitry
- Push Buttons
Step 3: ACCELEROMETER
Why we used an accelerometer?
An accelerometer has great specifications and properties that helped us work with an ease to achieve the desired result when it comes to this project. Below are some of those specifications.
· 3-axis sensing
· Small, low-profile package
· 4 mm × 4 mm × 1.45 mm LFCSP
· Low power - 350 μA (typical)
· Single-supply operation (1.8 V to 3.6 V)
· 10,000 g shock survival
· Excellent temperature stability
· BW adjustment with a single capacitor per axis
· RoHS/WEEE lead-free compliant
Step 4: LIQUID CRYSTAL DISPLAY
Step 5: FLEX SENSOR
The main or heart our project is the flex sensor. One side of the sensor is printed with a polymer ink that has conductive particles embedded in it. When the sensor is straight, the particles give the ink a resistance of about 30k Ohms. When the sensor is bent away from the ink, the conductive particles move further apart, increasing this resistance (to about 50k-70K Ohms when the sensor is bent to 90°). When the sensor straightens out again, the resistance returns to the original value. By measuring the resistance, you can determine how much the sensor is being bent.
Step 6: DIODES , LED ,RESISTORS ,CAPACITORS
Diodes of number IN4001, IN4002, IN4003, IN4004, IN4005,IN4006 and IN4007 have maximum reverse bias voltage capacity of 50V and maximum forward current capacity of 1 Amp.
Diode of same capacities can be used in place of one another. Besides this diode of more capacity can be used in place of diode of low capacity but diode of low capacity cannot be used in place of diode of high capacity. For example, in place of IN4002; IN4001 or IN4007 can be used but IN4001 or IN4002 cannot be used in place of IN4007.The diode BY125made by company BEL is equivalent of diode from IN4001 to IN4003. BY 126 is equivalent to diodes IN4004 to 4006 and BY 127 is equivalent to diode IN4007.
Diodes have the characteristic of passing current in only one direction only. However, unlike a resistor, a diode does not behave linearly with respect to the applied voltage as the diode has an exponential current-voltage ( I-V ) relationship and therefore we cannot described its operation by simply using an equation such as Ohm’s law.
Light emitting diode (LED) lighting is becoming more and more popular, as incandescent lamps are being phased out globally. LEDs have several advantages over incandescent lamps, including energy efficiency, robustness, long lifetime, and good temporal stability. The three latter features make LEDs attractive candidates as new photometric standards.
White LEDs do not produce a full spectrum, like an incandescent light bulb does. This has to do with the process that produces the light/photons. In an LED, when an electron crosses the PN junction, the electron itself drops to a lower energy state, and the excess energy is emitted as a photon. This voltage drop is basically constant, therefore the energy of the photons emitted, and the color of light produced is basically constant.
The unwanted inductance, excess noise, noise, and temperature coefficient are mainly dependent on the technology used in manufacturing the resistor. They are not normally specified individually for a particular family of resistors manufactured using a particular technology. A family of discrete resistors is also characterized according to its form factor, that is, the size of the device and position of its leads (or terminals) which is relevant in the practical manufacturing of circuits using them.
A capacitor or condenser is a passive electronic component consisting of a pair of conductors separated by a dielectric. When a voltage potential difference exists between the conductors, an electric field is present in the dielectric. This field stores energy and produces a mechanical force between the plates. The effect is greatest between wide, flat, parallel, narrowly separated conductors.
Step 7: During the Process
Step 8: USING TANKERCARD IN DISINGING
Using the tankercard was one of the interesting stage of the work as we first time we use it . and print all this model in the 3D printer which take a lot of time .
Step 9: SOFTWARE
project we used Raspberry Pi as the brain for running and simulating the system. Raspberry Pi is a general-purpose computer, usually with a Linux operating system, and the ability to run multiple programs. It’s best used when you need a full-fledged computer: driving a more complicated robot, performing multiple tasks, doing intense calculations (as for Bitcoin or encryption). In this chapter we will illustrate the main functions in Raspberry Pi and how to setup the software.
Raspberry Pi 3, used in the project, is a later version of the microcontroller family. Below are several specifications that led to choosing it.
Required things for the work
There are numerous equipment that are necessary post preparation of the Raspberry Pi. These things include:
· Power Supply
To connect to a power socket using micro USB (at least 2.5 amps)
· microSD card
To store all files and the Raspberry Pi OS operating system.
· Keyboard and a mouse
To type and move around system functions.
· TV or computer screen
To view the Raspberry Pi OS desktop environment
To connect the monitor
To play sounds on the system
2.3 Setting up the SD card
SD cards can be purchased with NOOBS, operating system installer for the Raspberry Pi, preinstalled from different retailers outside of Saudi Arabia. Since we couldn’t find one, the team had to install it following the beneath steps:
Step 10: SETTING UP THE SD CARD
Download and launch the Raspberry Pi Imager
Step 11: SETTING UP THE SD CARD
• After finishing the download, click it to launch the installer
Step 12: SETTING UP THE SD CARD
• Click the WRITE button
Step 13: SETTING UP THE SD CARD
· wait for the Raspberry Pi Imager to finish writing
· Once you get the following message, you can eject your SD card
Step 14: STARTING UP RASPBERRY PI
Pi doesn’t have a power switch. As soon as you connect it to a power outlet, it will turn on.
· Plug the power supply into a socket and connect it to your Raspberry Pi’s power port.
You should see a red LED light up on the Raspberry Pi, which indicates that Raspberry Pi is connected to power. As it starts up (this is also called booting), you will see raspberries appear in the top left-hand corner of your screen.
Step 15: STARTING UP RASPBERRY PI
When you start your Raspberry Pi for the first time, the Welcome to Raspberry Pi application will pop up and guide you through the initial setup.
- Click on Next to start the setup.
- Set your Country, Language, and Timezone, then click on Next again.
Click on Restart to finish the setup.
Step 16: TECHNICAL - WORK PIRNCIPLE
Force Sensor is use a resistive-based technology. The application of a force to the active sensing area of the sensor results in a change in the resistance of the sensing element in inverse proportion to the force applied. The principle behind the Flexi Force Sensor is that when the sensor is unloaded, its resistance is very high (greater than 5 MΩ). This resistance decreases when force is applied to the active sensor area. The sensors are constructed of two layers of substrate. This substrate is composed of polyester film .On each layer, a conductive material (silver) is applied, followed by a layer of pressure-sensitive ink. Adhesive is then used to laminate the two layers of substrate together to form the sensor. The silver circle on top of the pressure-sensitive ink defines the active sensing area. Silver extends from the sensing area to the connectors at the other end of the sensor, forming the conductive leads terminated with a solder able male square pin. In order for the Flexi Force Sensors to obtain correct readings, they must necessary to use a puck (is a piece of rigid material or polymer smaller than the sensing area). These pucks were needed because they translate a direct force into a more distributed force on the sensor, making them more sensitive. Pucks were created by using thin artificial leather trimmed slightly into a smaller area than the sensor area itself (7mm in diameter). They were attached by insertion in a special made glove.
Step 17: CALIBRATION
Calibration is the method by which the sensor's electrical output is related to an actual engineering unit, such as Pounds or Newton. To calibrate, apply a known force to the sensor, and equate the electronic circuit output to this force. The sensor should be calibrated at the same circumstance as for which testing will occur. This is important to get accurate results.
To verify and test the proposed system practically, placing different weights of values (203.39, 100.29, 98.55, 50.29) gram over the sensing area (puck) and distribute the applied load across the sensing area to ensure accurate force readings. Flex Force Sensor has been connected to an ohmmeter, each weight is produced specific resistance readings that enable the plotting of the curve of the sensor resistance R versus the weight W. This curve represents the behavior characteristic of the sensor. Placing different weights value (203.39, 100.29, 98.55, 50.29) gram over the sensing area (puck) the resistance output related to this weights are (6, 33.2, 39.9, 120) milliohm. Transfer these results to Microsoft Excel program to draw the results.
Then the voltage readings have been measured using the same weights and the same procedures of the pervious experiment then the curves of the sensor voltage V versus the weight W have been plotted. Each curve represents one word that it should display on LCD and heard by voice record module, Placing different weights value (203.39, 100.29, 98.55, 50.29) gram over the sensing area the voltage output related to this weights by using the first sensor V0 are (35, 20, 13, 4) volt. Below is characteristic for word (Hello).
Placing different weights value (203.39, 100.29, 98.55, 50.29) gram over the sensing area the voltage output related to this weights by using the second sensor V1 are (24, 16, 14, 9) volt.
The same procedure was done for the rest of the words configured for this project.
The relation between weights - voltages and weights - resistances should be linear. The nonlinearity may be obtained in the curves because of the differences in the Flex Sensors sensitivities, so that there are dissimilarities between the readings. The proposed experimental circuit uses an inverting operational amplifier arrangement to produce an analog output based on the sensor resistance and a fixed reference resistance (RF). In this circuit, the sensitivity of the sensor could be adjusted by changing the reference resistance (RF) and/or drive voltage (VT); a lower reference resistance and/or drive voltage will make the sensor less sensitive, and increase its active force range. The value of CF is used to eliminate the noise introduced in the circuit (forming low pass filter with cut off frequency depending on RF and CF. The cut off frequency can be calculated according to the equation:
This operational amplifier need to operate with 5v and - 5v that provided by the two regulators and these regulators have been provided with 9v by power supply or two rechargeable batteries.
Step 18: PROGRAMMING CODE
Step 19: SCHEMATIC DIAGRAM
Step 20: Final Oration
Step 21: Last Stage Pacing and Delivery of the Project
Step 22: *** Thank You ***
In the end of this lovely journey we dedicate this project with big thanks and a lot of appreciation to our Supervisor Eng. Majed Alsuraihi who helped us a lot with this project, Eng. Tariq Algamdi head of the electronic departments and to all our teachers in the electronics department, as well as Dr. Jaber Yamani and we hope that it would become well known application as we will improve it in the future as we expand our Knowledge in this field of electronics.
we had some engineers and doctor’s Those who have taught us well and we have all the affection and respect for them and It is not easy for us to leave this place and consider this to be the end of this journey , but we will keep in touch to gain more knowledge as much as we can.
Eng. Majdi Alhowsawi
Eng. Faisal Aleliany
Eng. Hamed Salamah
Eng. Mohammed Alzahrani