CONTENTS OF THE PRESENTATION• SECTION A: PROJECT OVERVIEW PART 1 : WHAT this project is all about PART 2: HOW this project/robot works PART 3: WHERE this robot can be used• SECTION B: TECHNICAL ASPECTS PART 1: List of Components employed PART 2: Circuit and Pin Diagram• SECTION C: CONCLUSION
WHAT this robot actually does?• Today, cell phone has displaced nearly all the old traditional devices of communication.• So, in this project we show that how we can control the movement of any small robot with the help of mobile phone.• And hence, by using this logic we can not only control the movement of vehicle but also switch on/off other accessories on robot.
• The movement is controlled by pressingrelevant keys on a mobile phone thatmakes a call to another mobile phoneattached to the robot.
HOW this 1. A mobile phone makes a call to the other mobile phone attached to the robot.robot works? 2. In the course of the call, if any button is pressed, a tone corresponding to the button pressed (called DTMF tone) is heard at the other end of the call, perceived by robot using the other phone. 3. The received tone is processed by the ATmega16 microcontroller with the help of DTMF decoder MT8870. 4. The decoder decodes the DTMF tone into its equivalent binary digit and this binary number is sent to the microcontroller. 5. The microcontroller is pre programmed to take a decision for any given input and outputs its decision to motor drivers in order to drive the motors for forward or backward motion or a turn.
DTMF: Dual Tone Multi Frequency• DTMF signalling is used for telephone signalling over the line inthe voice-frequency band to the call switching centre. Theversion of DTMF used for telephone tone dialling is known as‘Touch-Tone.’• DTMF assigns a specific frequency (consisting of two separatetones) to each key so that it can easily be identified by theelectronic circuit. The DTMF keypad is laid out in a 4×4 matrix, with each row representing a low frequency, and each column representing a high frequency. Pressing a single key (such as 1 ) will send a sinusoidal tone for each of the two frequencies (697 and 1209 Hz).
DTMF Decoder • A DTMF Decoder takes in DTMF D3 D2 D1 D0 tone and converts it into BCD1 0 0 0 1 code, output depending upon2 0 0 1 0 which key is pressed at the3 0 0 1 1 transmitter side.4 0 1 0 0 • A number of companies make5 0 1 0 1 chips which decode these DTMF6 0 1 1 0 signal. One such IC is HT 9170.7 0 1 1 18 1 0 0 0 • The device after detecting a valid9 1 0 0 1 tone-pair makes one of the pins* 1 0 1 0 high (StD) for a short duration and the output latch is updated (D0-D3)0 1 0 1 1 according to the received tone-pair# 1 1 0 0
H BRIDGE Concept for motor driver • An H bridge is an electronic circuit that enables a voltage to be applied across a load in either direction by turning S1-S4 On/Off. • These circuits are often used in robotics and other applications to allow DC motors to run forwards and backwards. •H bridges are available as integrated circuits(here L298), or can be built from discrete components.
MICROCONTROLLER• Microcontroller is a single chip that contains the processor(the CPU), non-volatile memory for the program (ROM orflash), volatile memory for input and output (RAM), a clockand an I/O control unit. Here, the function of microcontroller (PIC16F887A) is to control output based on the programmed embedded hex logic. The microcontroller continuously scans input logic. The input logic is 4BCD data from DTMF decoder and change in the logic level makes microcontroller to perform particular subroutine/tasks.
WHERE this robot can be used?• Agriculture and farming : “Remote-controlled robot uses thermal imaging to detect and eradicate termites” – Gizmag The Termibot carries video and thermal imaging cameras where human pest controllers cant go. When a telltale heat or moisture signature is detected, Termicam breaks termite nests open to confirm the infestation, then pumps pest control chemicals directly into the source.
• Military and security operations: “Had there been a high range, light weight robot which could go into the hotels where terrorists held guests hostage during the 26/11 attack and send the images from inside, the security forces could have perhaps handled the situation better and the casualties would have been limited.” “ This concept is taken from military application where such land rover works as Unmanned Guided vehicle (UGV) for spy operations, mine diffuser, bomb detector etc. in such application the movements of land rover can be controlled from very far remote and safe place (as there is practically no limitation on operating range)”
• Scope for learning : PCB designing and various steps involved. PIC Microcontroller and its interfacing Programming the microcontroller using C• Scope for improvement : This land rover can be further improved to serve specific purposes. It requires four controls to roam around. The remaining eight controls can be configured to serve other purposes, with some modifications in the source program of the microcontroller.
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