Introduction: Automatic Wheel Chair

About: I am an IOT passionate student working whole time on my projects and opens the new paths of developing

Nowadays, in our society, We are coming across a lot of old people and physically disabled people with their problems. So, we would like to help them with all our effort. We created a helping hand for them which can take them wherever they want and can manage them without any one’s help.

The automatic wheelchair is the device which came out from these ideas. This wheelchair can adjust in multiple push back angles to keep them in a comfortable position. Automatic wheelchair comes with multi controlling ability according to situation and person who uses it. In further discussion, we can go deeper into it. In the smart automated wheelchair, the hardware circuit is mainly used to recognize, digitalize and transmit the control signal to L239D IC. In this paper, we are using ATMEGA328 based development board. Development board is programmed using embedded C language in Integrated Development platform. Firstly, Voice module is trained with 4 commands. After that, the voice command is sent by the user. The microcontroller is used to check the signal associated with this command and compare it with the stored commands and performs the task related to this command. Here, in our project, we have used the self-developed application on the Android smartphone and then we have connected it with the Bluetooth module.

The Bluetooth module which is used is HC-05 to interface the wheelchair with Android and to navigate it. And finally, remote control features and manually operated joystick-controlled feature in the smart wheelchair are also added. The main reason behind adding a Bluetooth module is that it is the easiest way to go wireless in interfacing humans and computer.

Step 1: Required Sensors and Controllers

required elements are

1. Arduino UNO R3

2. Bluetooth module

3. servo motor X 2

4. wheels

5. duplicate wheel

6. motor driver(l298)

7. chassis

8. joystick

9. Bluetooth app phone


As both voice and remote-control modes belong to wireless communication. they require a medium to transfer data in between chair and interface. Here, Bluetooth is used as a medium to connect chair with wireless devices. In speech recognition mode, some commands are initially set by the developer in the user’s comfortable language. During the control of the chair, each command given by user will get decoded into some unique set of special characters which should be kept anonymous. The received analog data will be converted into digital data and transfer of data is done in the serial communication mode in 9600 baud rate. The data received by Bluetooth is in digital form, it later converted into analog form and verified with the commands which were being set by the developer. If it gets a ping, the operation which is corresponding to the particular instruction is executed.

On the other hand, the remote control is operated using the same medium. The encoding and decoding of data are similar to the above procedure. Through one remote, the number of chairs can be easily controlled just by selecting the profile of the desired chair. The remote control automatically connects to the individual Bluetooth medium after the user selects the preferred profile through the interface.


In the manual controlling mode, the user can drive his own chair using an interface called joystick. Basically, the joystick is a three-channel communication device which can be used in five combinations. Generally, it contains two axis X&Y whose value varies from 0 to 1024 and additionally it contains a switch which gives input zero or one. The algorithm for the chair is designed in such a way that each input corresponds to a particular function.


In this project, these motors are used for back push adjustment and plank adjustment of the chair. The range of servo motor is 0 to 180 degrees. In this project, the back push has been introduced with five comfortable angles and more angles can also be included.

Similarly, the plank can also be adjusted in the same manner, but this project uses only two angles.

Step 2: Functionality of the Chair


This chair perfectly fits for all kinds of people. Let us consider old people, they can’t move everywhere repeatedly like other people. They need some assistance to take them wherever and whenever they want to. Disabled people also face the same problem. But, their voice may still work. So, by taking their voices as the main key to driving the chair, we installed speech recognition system. Speech recognition system interacts with the people and takes the commands in their comfortable language. People can control their chair easily and can drive themselves without relying on others.

In case of people with physically challenged and can’t even raise their voice. We installed remote controlled mode in which chair can be controlled easily by an external person or mentors. Through the remote-controlled system, each and every function of the chair will be accessed. For example, in old age homes and hospitals, the count of people is high. So, the number of chairs are also high. The problem in this scenario is that the mentors get confused by the remote corresponding to a particular chair. To overcome this problem, we introduced “one to many” system. Through this, it interfaces with the mentor and provides them with an option to select the desired chair.


In parallel to voice and remote control, we also installed manual controlling mode. Without any external support, one can easily drive one’s chair by simply operating a joystick attached to it. There is no necessity that the person is to be educated. Even an illiterate can easily control by simply tilting the joystick. The joystick contains 5channels through which every function can be easily controlled.

Step 3: Plank Mode and Bed Mode


The extra feature for the chair is multiple angle adjustment. By sitting in one position continuously, people will feel some inconvenience. To avoid that, we are providing five multiple angles to which they can adjust chair in their comfortable position. The angle can be adjusted by any one of the following three modes.


To write something, or to do some work, they need some support which can hold tools for them. So, we created a plank mode in which it can provide a plank whenever it needs and removes plank by simply pressing a button.

Step 4: Arduino Code

Microcontroller Contest

Participated in the
Microcontroller Contest