Introduction to Microcontrollers using PICAXE (SES)

Third Edition AusVels Design, Creativity and Technology Introduction to Microcontrollers using PICAXE (SES) Steven Penna Micro2 Student Name:

Introduction to Microcontrollers using PICAXE Page 1. Student Learning Guide & Record Task Page Description Assessment 1 9 Summarize electrical fundamentals (pgs 4 8) Assessment 2 12 Summarize (Pages 10 12) Assessment 3 14 List a variety of DC batteries Assessment 4 16 Determine resistor values and use a multimeter to check the result Assessment 5 18 Review questions on resistors Assessment 6 21 Review questions on semi-conductors Assessment 7 22 Write a design brief Assessment 8 23 Evaluation criteria Assessment 9 25 Assemble the motor and gearbox Assessment 10 26 Check all components Assessment 11 28 Mount and solder components Assessment 12 35 Completely assemble your line tracking mouse Assessment 13 35 Check the solder joints Assessment 14 35 Check the components Assessment 15 36 Turn on the battery pack Assessment 16 42 Identify uses for microcontrollers Assessment 17 44 Review questions Batteries Assessment 18 46 Summarise Diode Assessment 19 48 Summarise and compare Buzzers and piezo transducers Assessment 20 50 Summarise Analogue and digital signals Assessment 21 52 Review questions Digital sensors (switches) Assessment 22 54 Review questions Light dependent resistors Assessment 23 55 Identify component circuit symbols Assessment 24 58 Write a design brief Assessment 25 59 Evaluation criteria Assessment 26 60 Check all components Assessment 27 61 Mount and solder components Assessment 28 65 Check the solder joints Assessment 29 65 Check the components Assessment 30 65 Connect the battery Assessment 31 65 Connect the KS1086 student experimenter module Assessment 32 74 Turn LED on when the switch is pushed Assessment 33 74 Alternative programming method Assessment 34 75 Using the binary system Assessment 35 76 Testing LEDs on pins 3, 4 and 5 Assessment 36 77 Traffic lights Assessment 37 77 For next loop Assessment 38 77 LED chaser - wiper Assessment 39 78 LED flasher wiper using binary numbers Assessment 40 78 Extension unit - what you can do next Assessment 41 89 Testing the Piezo Sounder Assessment 42 79 Produce 120 different sounds counting up Assessment 43 79 Produce 120 different sounds counting down Date completed Instructor's signature Copyright LAPtek Pty. Ltd. Design Creativity and Technology

Page 2. Introduction to Microcontrollers using PICAXE Task Page Description Assessment 44 79 Produce more sounds Assessment 45 80 Advanced for.next loop Assessment 46 80 Count down in steps of 1 Assessment 47 80 Count down in steps of 10 Assessment 48 80 Some good sounds Assessment 49 83 Calibrating the LDR Assessment 50 83 Testing the LDR as a digital switch Assessment 51 83 Testing the LDR as an analogue sensor Assessment 52 84 LDR demo Assessment 53 85 Extension unit What you can do next Assessment 54 85 Testing the switch Assessment 55 86 Putting it all together Assessment 56 87 Extension unit Assessment 57 88 Write your own program Assessment 58 88 Extension units Assessment 59 89 Quick reaction game Assessment 60 95 Assessment 61 96 Add another LED Testing the infra-red remote control and receiver Assessment 62 96 Extension unit game - What you can do next Assessment 63 99 Mount and solder components for L293D motor driver Assessment 64 100 Graphically explain how an H-bridge works Assessment 65 107 Summarise aesthetics Assessment 66 108 Reflection Assessment 67 110 Ergonomics in action (group work) Assessment 68 113 Write a design brief Assessment 69 114 Carry out research Assessment 70 117 List of materials and components Assessment 71 118 Evaluation criteria Assessment 72 120 Concept drawings Assessment 73 122 Design options Assessment 74 126 Draw preferred design option Assessment 75 130 Orthographic drawing of preferred design option Assessment 76 131 Make a scale model of your preferred design option Assessment 77 132 Justification of preferred option Assessment 78 132 Production plan Assessment 79 135 Make your product/model Assessment 80 135 Reflections Assessment 81 136 Complete the effort and achievement Assessment 82 142 Risk assessment Assessment 83 143 Evaluation report (Assess. Rubric pgs 137-139) Assessment 84 145 Maintain a record of the production work Assessment 85 153 Design & manufacture an automatic vehicle Date completed Instructor's signature Copyright LAPtek Pty. Ltd.

Introduction to Microcontrollers using PICAXE Page 3. LEARNING INTENTIONS: What are you learning: You are learning to develop design briefs that include considerations and constraints and undertake research relevant to the design brief. You will also learn how to implement a range of production processes using tools, equipment and machines safely and use previously developed evaluation criteria to analyse processes, components, materials, tools and equipment and make appropriate suggestions for changes to these to improve outcomes. Why are you learning this: To know how to use research and design briefs to make prototype products and have recorded the results in a folio. How do you know when you have learnt this: When you can use the design process to make a programmable prototype model using equipment, materials, tools and components safely and produced a folio that represents your work and research. STUDENT OUTCOMES: All students will be able to use a design brief, to design and make a line tracking mouse using the design process, taking into account the aesthetics and ergonomics of the product. Most students should be able to use two design briefs to design, record and make a line tracking mouse and assemble and program a14m2 Picaxe controller (electronic circuit). Some students could use three design briefs to design, record and make a line tracking mouse, assemble and program the 14M2 Picaxe controller (electronic circuit) and design and make a model using Picaxe and the design process, taking into consideration the aesthetics and ergonomics of the products. IMPORTANT NOTE FOR INSTRUCTORS Research has shown that student outcomes are greatly improved when they have a sound understanding of the vocabulary used in the subject. With this in mind a glossary has been included in the back section of the workbook. Have fun with your students by doing word searches, word games, rhyming words, mind maps, concept maps, simple tests and questions. All these activities will help your students remember the new words. Set yourself a goal to ensure that all of your students get to know all of the new words that they encounter in your subject. Steve Penna

Introduction to Microcontrollers using PICAXE Page 15. RESISTORS Resistors are components used to control the size of the current that flows in an electrical/ electronic circuit. The greater the resistance, the smaller the current. Resistors may be made from carbon, metal oxide or a coil of wire. Resistors are probably the most commonly used class of components in electronics. The resistors most commonly used in electronic circuits are the fixed value resistor, the variable resistor and the light-dependent resistor. Resistance is measured in ohms (Ω). 1. Fixed value resistors Fixed value resistors are made in sizes to suit the power rating of the resistor. Those shown on the right are typical low power resistors with a power rating of one watt or less. Because these resistors are so small, it is not possible to print their resistance value on the body of the resistor. Instead a series of coloured bands are printed around the body of the resistor. Each colour represents a number and the resistance value is therefore determined by reading the colour code. The colours used in the resistor colour code are shown below. Circuit symbol or 1W ½W ¼W Fixed value resistors (B1) (standard) Multiplication factors and symbols M mega 1,000,000 (10 6 ) k kilo 1,000 (10 3 ) m milli 0.001 (10-3 ) micro 0.000,001 (10-6 ) n nano 0.000,000,001 (10-9 ) P Pico 0.000,000,000,001 (10-12 ) Four and five band resistor colour code

Page 16. Introduction to Microcontrollers using PICAXE The following examples show how to use the colour code for four and five band resistors. The first two bands (or three for five band resistors) are given a number, the next band is the multiplier and the last (on the right) is the tolerance band. brown black orange gold 1 0 x 1000 ± 5% = 10,000 or 10K Ω Four band resistor yellow violet black orange brown 4 7 0 x 1000 ± 1% = 470,000 or 470K Ω Five band resistor ASSESSMENT 4: DETERMINE RESISTOR VALUES AND USE A MULTIMETER TO CHECK THE RESULT Use the following process to determine the value of 15 fixed resistors that have been provided by your instructor. 1. Insert the resistors into a clean sheet of white paper. 2. Read the colour bands to determine resistor value. Write the value next to the applicable resistor. 3. Obtain a multimeter from your instructor. 4. Set the multimeter to ohms and the right scale for the resistor that you are checking. 5. Write the multimeter reading next to your previous recording for the resistor. 6. Observe the results. 7. Write an evaluation of your recordings that includes; your recordings compared to the multimeter recordings and an explanation of the differences if there is one. Evaluation...........................

Page 36. Introduction to Microcontrollers using PICAXE ASSESSMENT 15: TURN ON THE BATTERY PACK Check the 4 AA batteries are in the battery box correctly. Connect the battery box to the battery snap and put your finger on the IC. If it starts to get hot remove the battery box immediately as there is a problem most likely that the chip or the battery snap wires are around the wrong way. HOW IT WORKS Here we go, the big test. Complete the following. 1. Using black electrical tape, create a twisting and turning route for your Line Tracking Mouse. 2. Switch power to "ON" 3. Put your Mouse on the route that you designed. The black line should be within the three interrupters detecting range, 4. Gently move the Mouse body to start it running. Example 1 Example 2 Example 3

Introduction to Microcontrollers using PICAXE Page 37. ASSESSMENT RUBRIC YEAR 10 INVESTIGATING AND DESIGNING LINE TRACKING MOUSE Name: Teacher: Date : Level 9.0 Level 9.5 Level 10 Identified evaluation criteria based on the design considerations and constraints of a student-developed design brief for the development of a line tracking mouse. Identified considerations and constraints within a studentdeveloped design brief that required research, and development of a range of related evaluation criteria Identified considerations, constraints and the needs of a variety of client/user groups within the design brief. Then researched and located information relevant to the design brief and use it to help with their design. Researched the design brief specifications, such as the characteristics and properties of materials, components and production techniques. Researched and identified considerations and constraints, for the design of the line tracking mouse, including the needs of a client or user, and a range of design factors, and the characteristics and properties of materials or components. Generated a range of alternative possibilities, used appropriate technical language, and justified their preferred option, explaining how it provided a solution to the problem, need or opportunity. Developed a range of design alternatives and a justified the preferred option, with evidence that decisions are based on design specifications and an understanding of materials and components Developed and justified the preferred design option from a range of alternatives, using appropriate technical language, detailed evidence of investigation of design considerations, and showed an understanding of the relationship between inputs, processes and outputs. Made critical decisions on materials, systems components and techniques based on their understanding of the properties and characteristics of the materials and of the relationship between inputs, processes and outputs (Systems approach). Logically sequenced and planned the production stages, and listed the resources required, including availability of equipment and facilities. Logically sequenced and detailed planning of production stages, showing resources and calculation of time and costs Effectively used ICT equipment, techniques and procedures to support the development of their design and planning. Students take account of function and performance, energy requirements, aesthetics, costs, and ethical and legal considerations that address the requirements of design briefs. Used ICT equipment and techniques, such as computeraided design (CAD) to support stages of the design process. Used ICT equipment and techniques, such as computer-aided design (CAD) and modelling, to support stages of the design process Identified a range of criteria for evaluating their line tracking mouse and planned a realistic and logical sequence of the production stages, incorporating time, cost and resources needed for production. Level recorded 9.0 9.5 10

Page 42. Introduction to Microcontrollers using PICAXE ASSESSMENT 16: IDENTIFY USES FOR MICROCONTROLLERS Complete the following questions to help you to display your understanding of micro controllers. 1. Microcontrollers are used in many electronic devices, vehicles, home appliances, alarms etc. Write three applications where you think microcontrollers would be used in those systems. 2. Explain what a microcontroller is. 3. Explain the similarities between a microcontroller and a personal computer. ELECTRONIC COMPONENTS FOR THE 14M2 PIC STARTER MODULE To build the 14M2 PIC Starter Module you will be using a PIC controller, light emitting diodes, piezo sounder, light dependant resistor, ceramic and electrolytic capacitors, slide switch and a diode. The following pages describe each of the components in more detail. For some of the components, it will further reinforce what you have already learnt. Reading the next few pages should provide you with the basic knowledge necessary to successfully assemble your first programmable microelectronic circuit.

Voltage Page 52. ASSESSMENT 21: Introduction to Microcontrollers using PICAXE REVIEW QUESTIONS DIGITAL SENSORS (SWITCHES) Answer the following questions, they will help you revise what you have learnt about digital sensors (switches). 1. What is a digital sensor? 2. Identify three applications for a push switch. i)... ii)... iii)... 3. Identify two applications for a reed switch. i)... ii)... 4. Display on the digital signal below when the digital sensor (switch) is on and off. 5V 0V Time 5. Identify three applications for a micro-switch. i)... ii)... iii)... 6. Does a digital sensor (switch) send a digital or analogue input signal to the microcontroller?

Page 58. Introduction to Microcontrollers using PICAXE 14M2 PIC STARTER MODULE ASSEMBLY INSTRUCTIONS What: To learn how to assemble a 14M2 micro controller and student experimenter module, then program the 14M2 to gain a desires output. Why: To learn the basic programming language. When you can understand and successfully program the module. KS1084 14M2 PIC STARTER MODULE AND KS1086 STUDENT EXPERIMENTER MODULE The kits are available from: School Electronic Supplies P.O. Box 636, Heathmont, Vic. 3135 Phone: 03-8802 0628 Fax: 03-8802 0629 DESIGN BRIEF 14M2 Starter module A design brief is a written explanation outlining the aims and objectives of a design project. The design brief ensures that important design issues are considered and questioned before you as the designer commence work. ASSESSMENT 24: WRITE A DESIGN BRIEF Write a design brief that clearly states the problem to be solved and the aims and objectives that you have in the making of your first advanced electronic circuit. Commence your design brief with 'I am going to make... YOUR DESIGN BRIEF.....................

Introduction to Microcontrollers using PICAXE Page 83. ASSESSMENT 49: CALIBRATING THE LDR Main: The following program calibrates the LDR: make label called main readadc 0,b1 read channel 0 into variable b1 debug b0 transmit value to computer pause 1000 short delay of 1000ms goto main jump back to start After this program is run a debug window showing the value of variable b0 will appear on the computer screen. As the light falling on the LDR sensor is altered, the variable will show the current sensor reading. NOTE: To use debug you need to have the download cable attached. ASSESSMENT 50: TESTING THE LDR AS A DIGITAL SWITCH The LDR when connected to input 0 can be tested as a digital switch by a simple program which will switch output 4 on and off according to the light level. Because this is an if then command there is no space between input and 0. Use your finger to cover the LDR and note what happens. Main: If input0 is on then Dohigh Low 4 Goto main Dohigh: High 4 Goto main ASSESSMENT 51: TESTING THE LDR AS AN ANALOGUE SENSOR The LDR when connected to input 0 can be tested as an analogue sensor by using the program below. The readadc command is used to read the analogue value (a number between 0 and 255) into variable b1. Once the number is in b1, it can be tested to see if it is greater than 100 or greater than 50. If it is greater than 100 output 4 is switched on. If it is between 50 and 100 output 5 is switched on and if it is less than 50 then both outputs are switched off. Use your finger to first shade the LDR and then cover it and note what happens. You will be able to see the value of variable b1 change on the debug screen but you need to have the download cable connected to do this.

Introduction to Microcontrollers using PICAXE Page 93. INFRARED CONTROL As you can see from the schematic diagram right that the circuit is not complicated and only uses a few components. The parts list should be self explanatory and the circuit is easily built using a breadboard and teaming it up with your KS1084 14M2 module. Note that the input pin used on the 14m2 is pin 3 Infrared control circuit Infra-red control circuit mounted on a breadboard AR1012 UNIVERSAL INFRA-RED TV STYLE REMOTE CONTROL Before use, the universal remote must be programmed with the special Sony transmit code. 1. Insert 2AAA size batteries. 2. Press S and B at the same time. S is in the centre of the arrows. The top left red LED should light up. 3. Press 0. The LED should flash. 4. Press 1. The LED should flash. 5. Press 3. The LED should go out. 6. Press the red power button (top right). Note that buttons A, C, D, E, F and G are for setting the remote control into different modes which are not suitable for using with PICAXE. If one of these button is pressed accidentally then press the B button to return the correct mode. We recommend always pressing the B button before use. When a key is pressed on the remote control, the red LED in the top left corner will light and flash and a number will be sent to the IR receiver connected to the PICAXE microcontroller. The numbers will correspond to the keys pressed as listed below:

Introduction to Microcontrollers using PICAXE Page 101. ASSESSMENT RUBRIC YEAR 10 INVESTIGATING AND DESIGNING ASSEMBLE AND PROGRAM A 14M2 PICAXE CONTROLLER Name: Teacher: Date : Level 9.5 Level 10 Level 10.5 Identified considerations and constraints within a studentdeveloped design brief that required research, and development of a range of related evaluation criteria on page 59. Researched and identified considerations and constraints, for the design of the 14M2 picaxe controller, including the needs of a client or user, and a range of design factors, and the characteristics and properties of materials or components. Developed and justified the preferred design option from a range of alternatives, using appropriate technical language, detailed evidence of investigation of design considerations, and showed an understanding of the relationship between inputs, processes and outputs. Logically sequenced and detailed planning of production stages, showing resources and calculation of time and costs Used ICT equipment and techniques, such as computeraided design (CAD) and modelling, to support stages of the design process Identified considerations, constraints and the needs of a variety of client/user groups within the design brief. Then researched and located information relevant to the design brief and use it to help with their design. Generated a range of alternative possibilities, used appropriate technical language, and justified their preferred option, explaining how it provided a solution to the problem, need or opportunity. Made critical decisions on materials, systems components and techniques based on their understanding of the properties and characteristics of the materials and of the relationship between inputs, processes and outputs (Systems approach). Effectively used ICT equipment, techniques and procedures to support the development of their design and planning. Students take account of function and performance, energy requirements, aesthetics, costs, and ethical and legal considerations that address the requirements of design briefs. Identified a range of criteria for evaluating their robot and planned a realistic and logical sequence of the production stages, incorporating time, cost and resources needed for production. Level recorded 9.5 10 10.5 Independently developed a design brief, including specifications (considerations and constraints) and identification of a range of relevant evaluation criteria. Carried out research, based on specifications in the design brief, the needs of the likely user/consumer/client, related design factors, proposed materials, components and processes, and a social, ethical or environmental issue related to the design brief, materials or production. Generated a range of clearly communicated design ideas (including, for example, supporting sketches, models) and a justified preferred option, using a range of drawing and communication techniques, conventions, and used appropriate terminology. Displayed evidence of design decisions relevant to the design brief, including design considerations and/or design elements and principles, proposed materials, components and production processes provided in, for example, discussed in the design brief and evaluation criteria, design annotations, evaluation grids, and justification of the preferred option. Developed a logically sequenced plan and a list of the materials, components, equipment and safety measures needed to produce a design, including a timeline and costing.

Page 102. Introduction to Microcontrollers using PICAXE ASSESSMENT RUBRIC YEAR 10 PRODUCING ASSEMBLE AND PROGRAM A 14M2 PICAXE CONTROLLER Name: Teacher: Date : Level 9.5 Level 10 Level 10.5 Production a 14M2 picaxe controller that is close to commercial standards in terms of the quality, aesthetic, functionality, and/or performance requirements of the design brief on page 58. Implemented a range of production and finishing/presentation processes with minimal supervision and competently used complex tools and equipment, with limited guidance on safety. Justified the selection and use of materials based on physical, chemical, sensory or aesthetic properties or system components to achieve the expected outputs or other requirements of the design brief on page 58. Modified or adapted production methods to overcome difficulties, with any changes to the design plan clearly explained. Showed consideration to safety requirements. Recorded progress. Produced a robot that met the requirements of the design brief, showing consideration of quality, aesthetics and functionality/performance, and met the expectations of a user/consumer. Selected and competently handled materials, and system components, showing an understanding of characteristics and properties or function in a system. Selected and used a range of complex tools, equipment, and production and finishing/presentation processes, showing, after practice and trailing, a high level of accuracy, competency, responsibility and safety Displayed skills in managing production processes recording of production work (for example, in a journal or log, using ICT (where appropriate) that described the use of the production plan and details of any modifications carried out. Produced a robot that met the requirements of the design brief, showing consideration of quality, aesthetics and functionality/performance, and met the expectations of a user/consumer. Selected and competently handled materials, and system components, showing an understanding of characteristics and properties or function in a system. Selected and used a range of complex tools, equipment, and production and finishing/presentation processes, showing, after practice and trailing, a high level of accuracy, competency, responsibility and safety Displayed skills in managing production processes recording of production work (for example, in a journal or log, using ICT (where appropriate) that described the use of the production plan and details of any modifications carried out. Level recorded 9.5 10 10.5

Introduction to Microcontrollers using PICAXE Page 103. ASSESSMENT RUBRIC YEAR 10 ANALYSING AND EVALUATING ASSEMBLE AND PROGRAM A 14M2 PICAXE CONTROLLER Name: Teacher: Date : Level 9.5 Level 10 Level 10.5 Used, safe procedures to test their 14M2 Picaxe controller. Used student-developed criteria, detailed reference to test findings, and feedback from teacher and peers, to evaluate their 14M2 Picaxe controller in terms of safety, function, suitability for the intended purpose and use of resources. Revised equipment used, processes, materials and components and justified changes proposed to produce an improved outcome for the 14M2 Picaxe controller. Critically analysed the social, cultural, legal and environmental impacts of their own and others 14M2 Picaxe controller, and of an innovative new technology. Used an appropriate qualitative testing or checking method Used a range of evaluation criteria developed from the design brief, and input from others (particularly users/consumers) to assess their 14M2 Picaxe controller in terms of suitability for the intended use, function/performance, appearance, quality and usability. Considered and analysed the efficiency and efficacy of the production processes and the functional 14M2 Picaxe controller in terms of safety and risk. Identified the possible social, environmental, cultural and ethical/legal impacts of their 14M2 Picaxe controller and those of others. Used an appropriate qualitative testing or checking method Used a range of evaluation criteria developed from the design brief, and input from others (particularly users/consumers) to assess their 14M2 Picaxe controller in terms of suitability for the intended use, function/performance, appearance, quality and usability. Considered and analysed the efficiency and efficacy of the production processes and the functional 14M2 Picaxe controller in terms of safety and risk. Identified the possible social, environmental, cultural and ethical/legal impacts of their 14M2 Picaxe controller and those of others. Level recorded 9.5 10 10.5

Page 104. Introduction to Microcontrollers using PICAXE INTRODUCTION TO THE DESIGN PROCESS The design process is used to design and manufacture a prototype of an idea. The design process that you will be using to create your models comprises of the following stages. The Design Process

Introduction to Microcontrollers using PICAXE Page 105. AESTHETICS AND ERGONOMICS What: You will be learning the importance of aesthetics and ergonomics and the roles they play in the design process. Why: To enable you to design an individual creative piece that takes into consideration how people feel about and use your product. Read the following five pages to help you to understand what aesthetics and ergonomics is, then when you consider them in the design process for your models. Until recently, function and cost were the only factors that mattered when people bought or manufactured new products, but that s all changing. People no longer simply expect the product to be functional and usable. They also expect it to bring pleasure. Things like aesthetics of the product; the way it looks, the feel of the material, the tactile response of the controls, and how it suits the user (ergonomics) is what gives them pleasure. A working knowledge of aesthetics and ergonomics will help you in designing your products. Let s have a look them. AESTHETICS What is aesthetics? Aesthetics is all about how you feel (your senses) about a product and how you respond to it. Putting it simply, if something is aesthetically pleasing to you, you like it and if something is aesthetically displeasing to you, don t like it. Aesthetics involves all of your senses vision, hearing, taste, touch and smell. On the right is one of David Roys kinetic wood sculptures. Is it aesthetically pleasing to you? Is it aesthetically displeasing to you? Discuss this with your friend, then share your thoughts on how you feel about David s work, with the class. If you would like to see David s kinetic wood sculpture work, go to his web site, it is worth the visit. Kinetic wood sculpture by David Roy SENSES The following identifies your senses and how you use things to determine how you feel about a product. VISION Colour Shape Pattern Line Texture Balance Scale Movement A quality that products have, and which can be seen. A distinctive form An artistic or decorative design A contour or an outline The surface of a material, esp as perceived by the sense of touch Evenly proportioned, balanced, The ratio between the size of something real and that of a model or representation of it A particular manner of moving. Vision

Page 152. Introduction to Microcontrollers using PICAXE EXTENSION UNIT KS1071 L293D MOTOR DRIVER MODULE The L293D is a quadruple high-current half-h driver. It is designed to provide bidirectional drive currents of up to 600ma from 4.5 volts to 36 volts DC. This device is designed to drive inductive loads such as relays, solenoids, DC and bipolar stepping motors in positive supply applications. All inputs are TTL compatible. Each output is a complete totempole drive circuit, with a Darlington transistor sink and a pseudo- Darlington source. Drivers are enabled in pairs, with 1 and 2 enabled by 1,2EN and drivers 3 and 4 enabled by 3,4EN. When an enable output is high, the associated drivers are enabled and their outputs are active and in phase with their inputs. When the enable input is low, those drivers are disabled and their outputs are off and in the high impedance state. With the proper data inputs, each pair of drivers forms a full-h (or bridge) reversible drive suitable for solenoid and motor applications. The KS1071 L293D motor driver module is designed for use with a PICAXE microcontroller for interfacing with small DC motors or solenoids. The L293D can be powered from the same 4.5 volt power supply as the PICAXE to control a small 3 volt motor such as the PM9000. Higher voltage motors of 4.5 to 36 volts can be used with the L293D by using a separate regulated supply connected to pin 8. A 220nF polyester capacitor should be connected directly across the motor terminals to prevent motor noise from interfering with the circuit. ASSEMBLY HINTS The printed circuit board for the KS1071 features an integral heatsink on pins 4, 5, 12 and 13. It is recommended that the L293D be soldered directly to the PCB without the use of an IC socket so that optimum performance can be achieved without overheating. The L293D is designed to run warm and does have inbuilt over temperature protection. The screw terminal blocks need to be ganged together using the dove-tail grooves prior to soldering into the PCB. The L293D IC is static sensitive and requires special handling RESOURCES Programming And Customising The PICAXE Microcontroller by David Lincoln and by visiting www.picaxe.co.uk.

Introduction to Microcontrollers using PICAXE Page 153. ASSESSMENT 85: DESIGN AND MANUFACTURE AN AUTOMATIC VEHICLE Use your 14M2 PIC starter module and the L293D motor driver module that you completed, to design and manufacture a vehicle that when it strikes an object will reverse, change direction then proceeds forward. WIRING DIRECTION FOR YOUR VEHICLE: Starter Module L293D Driver Terminal Block Micro Switch Motors Pin 0 Leg 10 Pin 1 Leg 15 Pin 2 Leg 2 Pin 3 Terminal 2 Pin 4 Leg 7 +V Leg 9 +V Terminal 1 G Leg 12 (G) Bridge Leg 1 and 8 Bridge Leg 9 and 16 Leg 3 Leg 6 Leg 11 Leg 14 Leg 13 (G) Terminal 4 Bridge Leg 16 and 1 Terminal 1 Terminal 1 Terminal 3 Terminal 3 1K resistor across terminals 2 and 3 10K resistor across terminals 3 and 4 Left hand (centre) Right hand (centre) Left hand (inside) Right hand (inside) Left hand motor (top) Left hand motor (bottom) Right hand motor (top) Right hand motor (bottom) 104 ceramic capacitor across both motor terminals on left hand and right hand motors