Embedded Based Student Monitoring System

1
L.Sabaresh Kumar, 2S.Kunguma Vishnu,3 M.Roja, 4S.Gayathri,5A.Athiraja,
1,2,3,4
Students, 5Assistant Professor
1,2,3,4,5
Department of Electronics and Communication Engineering
1,2,3,4,5
Rathinam Technical Campus, Coimbatore,

Abstract— As we all know, students in the class with the absence of a staff are a dreaded nightmare for the neighboring
classes, where an important chapter is being taught. So, in order to prevent this from happening, we have the smart class
monitoring system. The device built with a sound sensor and audio board, which detects the levels of decibels produced
from the class without a staff. If the decibel reaches the limit set in the device, it automatically triggers the voice
message asking the students to keep silence and also will send the notification to the concerned head of the department
informing that the class is in the absence of a staff. this device notifies us whenever it detects loud conversation (the
sound level above 120db to 140db) and it also records the conversation and saves in a file. These devices are used in
silent zones like hospitals, libraries, labs, and also in schools and colleges to maintain decorum. This helps us to
maintain silence and also to identify noisy people so that necessary action can be against them.

Keywords: Smart class monitoring system, Automatically triggers, silent zones, hospitals

I. INTRODUCTION

As we know that speaking loudly is an annoying thing. Having such a co-worker in the office environment will
influence our work and productivity. When it comes to schools and colleges pedagogue or a praepostor can’t monitor
every last one all the time. It is very difficult to identify a noisy person. So it becomes obligatory to control students and
monitor the situation. This project is set to overcome these problems. So whenever sound crosses the certain sound limit
it will notify us and makes a small beep sound and also it records the sound which is above the set limits. So that we can
identify the noisy people and we can take the necessary actions. It is not just noise generated by students that are of
concern but electronic devices and other equipment can also make a loud noise which may disturb the students and
faculty. Through this device, we can also detect them and take necessary steps.

A. Electret microphone
The Electret microphone has two plates inside it just like a capacitor; the distance between the plates is directly
proportional to sound present in the environment. A very basic circuit to get started with microphone is shown below.
The recommended operating voltage is 2V but it can withstand up to 10V so you can even use a 9V battery, in the
circuit below I have used 5V to operate my microphone.

Always remember that microphone has polarity to make sure you connect the positive (output) terminal to supply
through the resistor and the ground terminal to the ground as shown in the circuit below.

An Electret Condenser microphone (a.k.a Condenser Microphone) is the most common type of transducer that is used to
detect or measure sound signals. It functions exactly as opposite of a normal speaker, that is when a sound signal is
detected it produces electrical signals.

B. Embedded System
It‘s a combination of hardware and software to perform a specific application. Embedded systems are commonly found
in consumer, industrial, automotive, medical, commercial and military applications. An embedded system is a
microcontroller or microprocessor based system which is designed to perform a specific task.

An embedded system has three components

It has hardware.
It has application software.
It has real time operating system (rtos) that supervises the application software and provide mechanism to let the
processor run a process as per scheduling by following a plan to control the latencies. Rtos defines the way the system
works. It sets the rules during the execution of application program. A small scale embedded system may not have rtos.
Easily customizable
Low power consumption
Low cost
Enhanced performance

II. EXISTING METHOD

The research aims to know the noise level by using the Arduino Uno as data processing input from sensors and called as
Sound Noise Level (SNL). The working principle of the instrument is as noise detector with the show notifications the
noise level on the LCD indicator and in the audiovisual form. Noise detection using the sensor is a condenser
microphone and LM 567 as IC op-amps, which are assembled so that it can detect the noise, which sounds are captured
by the sensor will turn the tide of sinusoidal voice became sine wave energy electricity (altering sinusoidal electric
current) that is able to responded to complaints by the Arduino Uno. The tool is equipped with a detector consists of a
set indicator LED and sound well as the notification from the text on LCD 16*2. The data acquisition system consists of
an analog sound sensor V2, Arduino Uno, display LED, and display seven segment. Sound sensor serves to convert
sound into electrical quantities. The microphone converts the sound pressure (Pa) to audio voltage (Volt). Noise
detection using the sensor is a electret condenser microphone with sensitivity of -56 dB relative to 1 V/µbar.

III. PROPOSEDSYSTEM

To overcome the problem that occurs in the existing system, we have proposed a methodology using embedded
system.In this project we will use a normal Electret Condenser microphone with Arduino and try measuring the sound
or noise pollution level in dB as close as possible to the actual value. We will use a normal amplifier circuit to amplify
the sound signals and feed it to Arduino in which we will use regression method to calculate the sound signals in dB. To
check if the values obtained are correct we can use

the “Sound Meter” android application, if you have a better meter you can use that for calibration. Do note that this
project does not aim to measure dB accurately and will just give values as close as possible to the actual value.

Fig.1 Block diagram

The block diagram of gsm based monitoring system is shown in block diagram waste bin is built on ardiuno board
platform. It is interfaced with a gsm modem (sim 900a) and the bin is equipped with sound sensor. Microcontroller is
used to interface the sensor system with gsm system. Then it sends the message to the concern person using gsm
system.16x2 lcd which shows warning message. Specification consists of arduino uno board which has atmega328 ic,
sound sensor module and gsm . Circuit for this arduino sound level meter is a very simple in which we have used the
lm386 audio amplifier circuit to amplify the signals from a condenser microphone and supply it to the analog port of
arduino. We have already used this lm386 ic to build a low voltage audio amplifier circuit and the circuit more or less
remains the same.
IV. ARDUINO UNO

A. ARDUINO UNO at Mega328

The Arduino UNO is a microcontroller board based on the ATmega328. It has 14 digital
Input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz crystal
oscillator, a USB connection, a power jack, an ICSP header, and a reset button. It contains
everything needed to Support the microcontroller; simply connect it to a computer with a USB cable
or power it with a AC-to-DC adapter or battery to get started. The Uno differs from all preceding
boards in that it does not use the FTDI USB-to-serial driver chip. The Uno and version 1.0will be
the reference versions of Arduino, moving forward. The Uno is the latest in a series of USB
Arduino boards, and the reference model for the Arduino platform; for a comparison with previous
versions.

Fig 5.1:
Arduino
Fig 2. Arduino UNO

V. PROGRAM AND OUTPUT

#include<LiquidCrystallcd>
LiquidCrystal
lcd(7,8,10,11,12,13);

int num_Measure = 128 ; // Set the number of measurements

int pinSignal = A0; // pin connected to pin O module sound sensor int redLed =
5;
long Sound_signal; // Store the value read Sound Sensor
long sum = 0 ; // Store the total value of n measurements long
level = 0 ; // Store the average value
int soundlow = 40;

int soundmedium = 500;

void setup ()
{

pinMode (pinSignal, INPUT); // Set the signal pin as input Serial.begin

(9600);
lcd.begin(16,2);

void loop ()

// Performs 128 signal readings

for ( int i = 0 ; i <num_Measure; i ++)

Sound_signal = analogRead (pinSignal);

sum =sum + Sound_signal;
}

level = sum / num_Measure; // Calculate the average value Serial.print("Sound Level: ");
lcd.print("Sound
Level= "); Serial.println
(level-33);
lcd.print(level-33);
if(level-33<soundlow)

lcd.setCursor(0,2);
lcd.print("Noise is
Normal");
digitalWrite(redLed,LOW
);
}

if(level-33>soundlow && level-33<soundmedium)

lcd.setCursor(0,2);
lcd.print("Noise is
Raising");
digitalWrite(redLed,LOW
);
}

if(level-33>soundmedium)

{
 lcd.setCursor(0,2);
lcd.print("Please Be
Quiet");
digitalWrite(redLed,HIG
H);
}

sum = 0 ; // Reset the sum of the measurement values

delay(200);
lcd.clear();

Fig 3. Displaying Output

VI. CONCLUSION
Thus the above project is an efficient noise detection with an automatic recording system that can be used in schools and
offices to identify noisy peoples. There are two aspects of the sound heard by the human ear. This aspect is loudness and
altitude. Loudness is related to energy in sound waves. The pitch of the sound states whether the sound is high like the
sound of a flute and a violin, or whether the sound is low as the sound of a bass and a drum. Physical quantity that
determines altitude is frequency. Human ear hearing range is between 20 Hz to 20,000 Hz. A tendency that the more
aged a person, then the person is increasingly unable to hear sounds with high frequency. In direct testing as a whole,
the device using a comparison scale obtained the results with the accuracy value of 99.93% and an error percentage of
0.067%. The next research is that it can be done to improve system design so that the results of 100% accuracy can be
obtained when measured.

REFERENCES

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