3. Implementation - sakshichougule/Women-Safety-device GitHub Wiki

This chapter concentrates on system specifications and their architecture. It also includes the algorithm and detailed Flow Chart.

3.1 Specifications and final system architecture

We have used the Arduino Uno Microcontroller board, power supply, GPS module, emergency switch, Buzzer, and GSM module.

3.1.1 Arduino Uno

The Arduino Uno Microcontroller board has 14 digital Input-Output pins, 6 analog InputOutput pins, and it can be programmed using the Arduino IDE tool. It is powered using a USB cable externally using a 9V battery, it accepts voltages between 7 and 20 volts.

3.1.2 Emergency switch

A switch is a gadget used to separate and associate an electric circuit voluntarily and to open and close a circuit. When the switch is pressed it will send signals to the microcontroller, which activates the GPS module and sends coordinates via GSM.

3.1.3 Regulated Power Supply

The power supplies change over high voltage Alternating current mains power to some reasonable low voltage supply for driving the electronic circuits.

3.1.4 GPS Module

GPS receiver is a route framework. GPS captures the signs and locates the victim’s position. The standard data format supported by the GPS is NMEA. NMEA stands for the National Marine Electronics Association. To understand the NMEA message structure. We shall consider the example below:

$GPRMC,162789.417,A,3621.5755,S,17898.3516,E,0.23,459.61,322698,*10

NMEA format starts with the $ character, and each data field is being separated by a comma. GP represents a GPS position RMC-Recommended, Minimum Specific GNSS Data 1 = Status of the data 2 = Latitude Value 3 = North/South Direction 4 = Longitude Direction 5 = West/East Direction 6 = NA 7 = NA 8 = Speed on ground 9 = Course on ground 10 = Variations 11 = Directional Variation 12 = Checksum

3.1.5 GSM modem

A GSM module is an advanced type of modem that has a slot for a SIM card and operates just like a mobile phone. They can be used for receiving and sending SMS and MMS messages. To control these Modem’s AT commands are used. AT is the abbreviation for Attention. Here in our project, we have used GSM Sim900A modem which is an easy long-range interface with a sim slot supporting 2G and 3G networks. It can be easily interfaced with a GPS module to receive and send information.

The AT commands used by the GSM modem are described in Table 3.1

3.1.6 Temperature Sensor

LM35 is an Integrated Circuit Temperature sensor as the input varies based on the temperature around it the output voltage also varies. It is an affordable and compact IC that can be used to measure accurate temperature. It has a range from -55°C to 150°C. It can be connected to the Arduino Uno Board.

3.1.7 Sound Sensor

A sound sensor helps to detect the sound if it exceeds the set threshold value. The sound level threshold is adjusted via an onboard potentiometer. When the sound level exceeds a certain threshold the led on the detector is illuminated.

3.1.8 Pulse Sensor

Pulse Sensor is basically a heart-rate sensor. It can be easily interfaced with Arduino. It has the capability of recording heart rate and heart rate variability. Pulse Sensor adds noise cancellation circuitry and amplification to the hardware. Pulse Sensor works with either a 3V or 5V Arduino power.

3.2 Algorithm

The Women Safety Device consists of various components that include: Arduino Uno Microcontroller, GPS modem, GSM modem, Buzzer, sensors like Temperature sensor, Sound sensor, Pulse sensor, and the Buzzer. All these components integrated together result in an efficient working device. The working of the Women safety device is discussed below: Step 1: Switch ON the power supply connection to power the Arduino Uno board, Buzzer, GSM with 5V supply, and GPS with 3.3V supply.

Step 2: If the Emergency switch is pressed.

Step 3: Buzzer starts beeping alerting the surrounding public and generates shock.

Step 4: The GPS module gets activated and starts tracking the latitude and longitude values of the woman’s location through the antenna and sends it through an SMS to the pre-registered mobile number using a GSM modem, along with this a phone call is sent to the registered number.

Step 5: Else if, the switch is not pressed but if the sensor readings exceed the threshold values, the current location of the victim is tracked by the GPS and is sent as an SMS via the GSM module, along with this buzzer is also alarmed to alert the surrounding public.

Step 6: Repeat the above steps until the power supply is turned OFF.

3.3 Flowchart The Flow Chart of the Project is shown in Figure 3.1

The actual purpose of this device is to provide safety to the woman in danger. In an emergency situation, the woman in danger shall press the push button, the controller will get the necessary commands, and activates the GPS module which calculates the current latitude and longitude values of the victim. These calculated values are sent to the registered mobile number via the GSM modem with a message caution: Danger Detected! HELP! , along with the functionality of alerting the surrounding public and distressing the abuser. However, due to some reasons if a woman has no time to act and press the emergency button when she is in danger, then the GPS tracker is activated based on the inputs from the sensors, if their values exceed the set threshold a message is sent to the registered mobile number. Hence the device will not compromise in its functioning and fulfill its task of protecting the women in need.