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Password Protected PC Controlled Robot with ATmega16

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Security is a prime concern in our day-today life. Everyone wants to be as much secure as possible. An access control for doors forms a vital link in a security chain. Traditional lock systems using mechanical lock and key mechanism are being replaced by new advanced techniques of locking system. These techniques are an integration of mechanical and electronic devices and highly intelligent. One of the prominent features of these innovative lock systems is their simplicity and high efficiency. Such an automatic lock system consists of electronic control assembly which controls the output load through a password. This output load can be a motor or a lamp or any other mechanical/electrical load.

In this project, we will learn How to design a password protected PC controlled robot with AVR ATmega16 microcontroller. Here, we use the PC keyboard as the input device to enter the password and to drive the robot 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 robot control, the user has to enter the correct password. PC will send the control signal(ASCII value of pressed key value) to the ATmega16 microcontroller through its serial port. But current generation PCs and Laptops do not have serial port in them, so we will use a USB to Serial converter cable which will create a virtual serial port in the PC /Laptop. Again, the output of USB to Serial cable can not be connected to microcontroller directly as the output voltage of USB to Serial Cable corresponds to RS-232 level. And the ATmega16 microcontroller needs TTL/CMOS voltage levels. For this, we will use MAX-232 voltage converter which will convert RS-232 voltage level to TTL one and vice-versa. The ATmega16 microcontroller will read the serial output of MAX-232 through its USART. First the user will enter the 4 digit password, each digit of which will be displayed in PC as star(*) and 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 receive the robot control signal from PC and it will process the control signal to know which key of the PC keyboard is pressed. After knowing which key of the PC keyboard is pressed, the ATmega16 microcontroller will send the required control signal to the DC motor driver (L293D) of the robot to drive the robot in the desired direction and it will send the direction of movement of robot to PC also(direction of robot will be displayed in PC). The control keys for the robot are F or f, B or b, L or l, R or r and S or s to drive the robot in forward, backward, left, right direction and to stop it respectively. Now, press different keys from the PC and drive your robot as you want.

Control Keys	Robot Direction
F or f	Forward
B orb	Backward
L or l	Left
R or r	Right
S or s	Stop

Softwares Required

• AVR Studio 4 Software
• WinAVR 2010 Software
• SinaProg Hex Downloader Software
• USBasp Driver
• RealTerm Terminal Software
• USB to Serial Driver

Hardwares Required

Name	Quantity
AVR Trainer Board-100 with ATmega16	1pc
AVR USB Programmer	1pc
12V, 1A DC SMPS Adaptor	1pc
RS-232 Driver Board	1pc
DC Motor Driver	1pc
Robot V 4.0	1pc
USB to Serial Cable-Y-105	1pc
1 to 1 Connector-Female to Female	1pc
10 to 10 FRC Female to Female Connector	3pc

Video

Connection Guide

The step-by-step connection guide for Password Protected PC Controlled Robot with ATmega16 is as follows