Sample Codes

Password Protected DTMF based Mobile/Cellphone Controlled Wheel Chair with ATmega16 for Physically Handicapped

Mark as Favourite

In this project, we will learn How to design Password Protected DTMF based Mobile/Cellphone Controlled Wheel Chair with AVR ATmega16 Microcontroller for Physically Handicapped. Here, we will use mobile keypad as the input device to enter the password and to drive the wheel chair in different direction. . The password is a 4 digit number. In our case the password is “1234” which can be changed in the program. To gain access of the wheel chair control, the user has to enter the correct password.

In this project, we will use two mobiles, one will be connected with the DTMF circuit and another will used to call the mobile attached with DTMF circuit. The Mobile attached with DTMF circuit will be kept in auto-answering mode. The password can be entered and the wheel chair can be controlled from mobile attached to the DTMF circuit by pressing its keys and also from any other mobile by calling to the mobile attached with DTMF circuit and pressing keys from the calling mobile keypad. In this project, the microcontroller will read the DTMF output through an external interrupt because the output of DTMF is latched in its output pins. The latched output can not used for password entry, it can only be used for wheel chair controlling. First the user will enter the 4 digit password each digit of which will be displayed in a 16X2 alphanumeric LCD as star(*). The microcontroller will compare the entered password with the set password. The system will ask to enter password till the correct password is entered by the user. After the correct password is entered, the microcontroller will read the wheel chair control signal from DTMF decoder and it will process the control signal to know which key of the mobile keypad is pressed. After knowing which key of the mobile keypad is pressed, the ATmega16 microcontroller will send the required control signal to the DC motor driver (L293D) of the wheel chair to drive the wheel chair in the desired direction and it will display the direction of movement of the wheel chair in the 16X2 alphanumeric LCD also.

The control keys for the wheel chair are 2, 8, 4, 6 and 5 to drive the wheel chair in forward, backward, left, right direction and to stop it respectively. Now, press different keys from both the mobile and drive your wheel chair as you want.

Control Keys	Wheel Chair Direction
2	Forward
4	Left
6	Right
8	Backward
5	Stop

 

 

Softwares Required

• Atmel Studio 6 Software
• SinaProg Hex Downloader Software
• USBasp Driver

Hardwares Required

Name	Quantity
AVR Trainer Board-100 with ATmega16	1pc
AVR USB Programmer	1pc
12V, 1A DC SMPS Adaptor	1pc
DC Motor Driver	1pc
DTMF Decoder	1pc
RG1602A 16X2 Alphanumeric LCD Green	1pc
3.5mm Audio Jack with Connector	1pc
1 to 1 Connector-Female to Female	4pc
10 to 10 FRC Female to Female Connector	4pc
Wheel Chair	1pc

Video

Connection Guide

The step-by-step connection guide for Password Protected DTMF based Mobile/Cellphone Controlled Wheel Chair with ATmega16 for Physically Handicapped is as follows