A Brief Description

1. Detecs object in front of a blind person

Allerts him/her with beeping sound. Frequency intensifies according to distance.

2. "Find my cane" feature

This smart stick can be paired with phone via bluetooth. So, user will be able to find this with the help of his phone.

3. Get a comprehensive idea of lighting environment

A push switch is available on top of the stick. User gets allerted about darkness after he/she pushes the switch.

Required Equipments

1. ATmega32a

2. Bread Board

3. 10K Ohm Resistors

4. Push Button

5. Buzzer

Sensors and Modules:

1. Sonar Sensor

2. BlueTooth Module

3. Light Dependent Resistor

Additional:

1. An Android Phone for Communication

2. A White Cane

How It Works?

1.

Sonar sensor sends an ultrasonic soundwave and receives an echo. The time gap between sending and receiving of sound wave correlated with the distance of an obstacle. ATmega counts this time and calculates the distance. If this distance is fairly small, buzzer gets a digital signal.

2.

Bluetooth is used for serial communication. A android phone can connect with this module. After connection, both data sending and receiving is possible. We send certain strings from phone to ATmega. ATmega checks the string and turns on/off the buzzer.

3.

Light dependent resistor(LDR) have high resistance in the dark. But resistance falls dramatically in presence of light. We attached a LDR with a resistor in series and measured the voltake across the LDR. This voltage is correlated to luminosity around the circuit. As voltage is analog, it was needed to convert it to digital signal. ATmega's ADC performs this tash as soon as the push button is pressed and give a buzzer output.

Block Diagram

Algorithm

See section "How It Works"

Detailed Pin Diagram

Circuit Diagram

Problems Faced

Baud Rate Problem:

We were getting wrong input/output character during bluetooth communication. As android phone's baud rate is 9600 as default. In single speed mode, we had to set an rounded UBRR value. It was causing the problem. After changing the communication to double speed mode, it was resolved.

Group Members Information

1. Nafiur Rahman Khadem

  1605045

2. Ahsanul Ameen Sabit

  1605047

3. Md. Washief Hossain

  1605058

Course Teacher

1. Tarek Mahmood

  Lecturer, CSE, BUET

2. Md. Masum Mushfiq

  Lecturer, CSE, BUET

                 Thank You!