CONTENTS List of Figures III List of Tables V Abstract VI Chapter 1: Introduction 1 Introduction 1 Problem Definition 2 Chapter 2: Block Diagram 3 Solar Panel 3 Battery 4 Microcontroller 4 Motor Driver IC (L293D) 4 12V DC Motor 5 Chapter 3: List of Components and Costing 6 Chapter 4: Circuit Diagram and Explanation 7 Microcontroller (AT89S51) 8 Solar panel 13 Battery 14 Motor 15 L293D 17 Resistor 19 Capacitor 20 LED 22 Chapter 5: Algorithm, Flowchart & Program 22 Algorithm of Project 22 Flowchart of Project 23 Program of Project 24 I Chapter 6: PCB Fabrication & Soldering 29 Description 29 PCB Materials 30 PCB Layout Designing Software 30 Software used For PCB Designing 31 Making an EAGLE Schematic 32 Making Layout using EAGLE 35 Precautions taken during PCB Designing 37 PCB Layouts 38 PCB Etching 40 PCB Drilling 43 PCB Soldering 45 Chapter 7: Troubleshooting and Testing 48 Troubleshooting 48 Description 48 Need of Troubleshooting 48 Steps Prior to Troubleshooting 49 Steps for Troubleshooting 49 Practical Troubleshooting 51 Testing the board with various tools 52 Chapter 8: Datasheet 56 Microcontroller AT89S51 56 L293D 56 Solar Panel 58 Rechargeable Battery 59 II Chapter 9: Advantages, Limitations, Future scope, 60 Applications and Conclusion Advantages 60 Limitations 60 Future Scope 61 Applications 61 Conclusion 61 Chapter 10: Bibliography 62 III LIST OF FIGURES Fig 1.1: Industry 1 Fig 1.2: Solar panel to battery 2 Fig 2.1: Block diagram of solar grass cutter 3 Fig 4.1: Circuit diagram 7 Fig 4.2: Microcontroller 89S51 8 Fig 4.3: Microcontroller mounted on a PCB 9 Fig 4.4: Pin diagram of 89S51 10 Fig 4.5: Microcontroller oscillator section 13 Fig 4.6: Solar panel 14 Fig 4.7: Battery 14 Fig 4.8: Basic principle of DC motor 15 Fig 4.9: Fleming’s left hand rule 16 Fig 4.10: 12V DC motor 16 Fig 4.11: Pin diagram of L293D 17 Fig 4.12: Resistor 19 Fig 4.13: Capacitor 20 Fig 4.14: LED 21 Fig 6.1: Control panel of eagle 33 Fig 6.2: Schematic editor of eagle 34 Fig 6.3: Board editor of eagle 34 Fig 6.4: Layout of microcontroller section 38 III Fig 6.5: Layout of motor section 39 Fig 6.6: PCB cutter 40 Fig 6.7: Cleaning of PCB 40 Fig 6.8: DIP coat 41 Fig 6.9: PCB oven 41 Fig 6.10: UV exposure 42 Fig 6.11: AGITATING PCB 42 Fig 6.12: Easy etcher 43 Fig 6.13: Drill machines 45 Fig 6.14: Soldering of PCB 46 Fig 6.15: Dry soldering 47 Fig 7.1: Multi meter 53 Fig 7.2: Cathode ray oscilloscope 54 Fig 7.3: IC tester 55 Fig 8.1: Pinout of L293D 57 Fig 8.2: Internal Block Diagram of L293D 58 IV LIST OF TABLES Table 3.1: Component list and costing 4 Table 4.1: Alternate functions of port 3 11 Table 4.2: Pin description of L293D 19 V ABSTRACT A Solar grass cutter is a machine that uses circular blades to cut a lawn at an even length. Even more sophisticated devices are there in every field. Power consumption becomes essential for future. Solar grass cutter is a very useful device which is very simple in construction. It is used to maintain and upkeep lawns in gardens, schools, college’s etc. We have made some changes in the existing machine to make its application easier at reduced cost. Our main aim in pollution control is attained through this. Unskilled operation can operate easily and maintain the lawn very fine and uniform surface look. In our project, solar grass cutter is used to cut the different grasses for the different application. Unlike commercial grass cutter this grass cutter works on the solar supply so it is very much energy efficient. There is no question of air getting polluted. The reason of using solar energy is solar energy is natural resource which is available in plenty. If we go for fuels like petrol, diesel it will cause pollution plus to this fuel causes lot of pollution of air. The grass cutter and vehicle motors are interfaced to an 8051 family microcontroller that controls the working of all the motors. The motor driver IC L293D is to boost the current which is given to the microcontroller to drive the motor. The current from microcontroller is very less so it cannot drive the motor so L293D must be used. VI CHAPTER-1 INTRODUCTION 1.1 INTRODUCTION The commercial grass cutter are very bulky in size and large amount of power consumption but the solar power grass cutter would be a good replace option of that. We have designed a “SOLAR GRASS CUTTER” which will be very useful in today’s industries. The grass cutter is powered by a solar panel and 12V DC rechargeable Lead-acid battery. The main component of the project is the microcontroller which will be driving the motors. The input coming from solar panel will be given to battery for charging purpose. The output from battery will be given to all part of the circuits. Figure 1.1 Industry Our project will meet all the requirements of need of industry. Here we are going to use a solar panel which will be converting all the energy coming from sun’s radiation directly in electrical equivalent DC voltage that will the overall power consumption and the battery needs to be recharged for less amount of time. 1 Figure 1.2 Solar panel to battery 1.2 PROBLEM DEFINATION In today’s modern world there is a lot a drastic change in amount of industries that we are seeing in our everyday life. At every day the amount of industry is growing like anything. India is sixth largest country in the world with most number of industries. When an industry is build it normally build in a very large area around 10,000 to 12,000 acres. But this total space is not completely occupied by the infrastructure of the industry but only ¼ part that is only 25% of land is used to build the infrastructure and the rest of the land is remain unused so grass starts coming on it. 2 CHAPTER 2 BLOCK DIAGRAM Fig 2.1: Block diagram of Solar Grass Cuter 2.1 Solar Panel: Solar panel refers to a panel designed to absorb the sun's rays as a source of energy for generating electricity or heating. Solar Photovoltaic panels constitute the solar array of a photovoltaic system that generates and supplies solar electricity in commercial and residential applications. Each module is rated by its DC output power under standard test conditions, and typically ranges from 100 to 365 watts. The efficiency of a module determines the area of a module given the same output. 3 2.2 Battery: The rechargeable batteries are lead-lead dioxide systems. The dilute sulphuric acid electrolyte is absorbed by separators and plates and thus immobilized. Should the battery be accidentally overcharged producing hydrogen and oxygen, special one way valves allow the gases to escape thus avoiding excessive pressure build-up, otherwise, the battery is completely sealed and is, therefore, maintenance-free, leak proof and usable in any condition. 2.3 Microcontroller: The AT89S51 is a low-power, high-performance CMOS 8-bit microcontroller with 4K Bytes of In-System Programmable Flash memory. The device is manufactured using Atmel’s high-density non-volatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional non-volatile memory programmer. By combining a versatile 8-bit CPU with In-System Programmable Flash on a monolithic chip, the Atmel AT89S51 is a powerful microcontroller which provides a highly-flexible and cost- effective solution to many embedded control applications. The AT89S51 provides the following standard f0eatures: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, two 16-bit timer/counters, a five-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power- down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next external interrupt or hardware reset. 2.4 Motor Driver IC (L293D): L293D is a dual H-bridge motor driver integrated circuit (IC). Motor drivers act as current amplifiers since they take a low-current control signal and provide a higher-current signal. This higher current signal is used to drive the motors. L293D contains two inbuilt H-bridge driver circuits. In its common mode of operation, two 4 DC motors can be driven simultaneously, both in forward and reverse direction. The motor operations of two motors can be controlled by input logic at pins 2 & 7 and 10 & 15. Input logic 00 or 11 will stop the corresponding motor. Logic 01 and 10 will rotate it in clockwise and anticlockwise directions, respectively. Enable pins 1 and 9 (corresponding to the two motors) must be high for motors to start operating. When an enable input is high, the associated driver gets enabled. As a result, the outputs become active and work in phase with their inputs. Similarly, when the enable input is low, that driver is disabled, and their outputs are off and in the high-impedance state.