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University of Hertfordshire

1. i 0 SS S ET T remo ERE Elo 20HZ 50 100 200 500 1K 5K MAIN USAGE OF ECM UNITS MICROPHONE CASSETTE TAPE RECORDER SONIC CONTROLLED TOY INTERCOM SYSTEM SONIC CONTROLLED SWITCH TELEPHONE SET DISCO LIGHT ANSWERING MACHINE ETC APPENDIX K Practical laboratory set up of the project
2. 0 80 configure the PI T to work with the Buffered I O Board PBDDR Oxff While 1 ADC 0x0 Initially transfer 0 0 data at ADC input delay 10 f ADC Assign ADC input data to variable F PBDR f Transfer this data on the port B of the PI T delay 10 This test also done successfully and the program code of the single input ADC test is present in Appendix B 3 7 3 Multiple Input ADC test As the main aim of the project is to make the development platform flexible so the different type of the sensors are connected at the eight input pins of the ADC board these sensors work simultaneously but at a time only one sensors istused to control the speed of the motor Any sensor chose according to the requirement of the application For example in the thermal power station high quality temperature sensor is used to maintain the temperature of the boiler up to the safe level by blowing alarm at the output or automatically switch off the boiler The testing of the multi inputs working of the ADC is done by the following program Unsigned char f Char switches Declare variable named switches Include PIT Initialise PI T While 1 Switches PADR if switches 0x01 port A data of PI T PAO switch active only 0 000000 lt ADC input AO works else PBDR 0 if switches 0x02 port A data of PI T PAI switch active only ADCPTR 0xD00002 ADC input Al works
3. Wa est Sis Vin a 5 APPENDIX F Bus Expander Board Internal Circuit Diagram 1 1 i n m m 19 D gon w 7 2 go SC m m X ER bus n n n D m E n mil mif pif ml mut DS pow 1 3 L mem m I m ami i gt 24 o D n M e n SC 1 T La Pm n m ibi 8 SL D X ml mer br n m ml 5 DN AR mm ane g is H 0 n Sin f Di wi ma Wan m w D D n 1 oe Votre 4 Ve Lis IW m D WI d M T 5 APPENDIX GI ADC Board Internal Circuit Diagram Site d Revision APPENDIX G 2 ADC Board Internal Circuit Diagram 1 2 3 4 H 6 yor D R BS M R R M MICROMATCHIG B Tile Number Revision H De Ma He d Pik Digoksin eS TAD 2 3 4 5 6 APPENDIX HI Connection Diagram Of Op Amp
4. PACKAGE DIMENSIONS inch mm 360 9 14 070 1 78 1 38 35 05 380 9 65 090 2 29 1 62 41 15 AWG 24 TINNED COPPER LEADS SS 420 10 67 285 7 24 B 440 11 18 305 7 75 de p LEAD DIA amp PLASTIC COATING NOT CONTROLLED WITHIN 10 2 5 OF CERAMIC SUBSTRATE PLASTIC COATED TO PROTECT ACTIVE SURFACE ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL CONTINUOUS POWER DISSIPATION Pp DEMAND 20 MINUTES DERATE ABOVE 25 C APp AT TEMPERATURE RANGE OPERATING AND STORAGE TA 40 to 75 ELECTRO OPTICAL CHARACTERISTICS 25 C 16HRS LIGHT ADAPT MIN g Resistance Ohms Sensitivity Maximum Response Time 3 ifc 11 25 Material typ Voltage typ 650K Las Type mea Ca T TOG 100 10 1 t o ilo VT43N1 VT43N2 VT43N3 VT43N4 EG amp G VACTEC 10900 PAGE AVENUE ST LOUIS MO 63132 USA TEL 314 423 4900 FAX 314 423 3956 WEB www egginc com optogrp APPENDIX J DataSheet Of Microphone Used in Sound Sensor 1 SENSITIVITY ODB 1V v bar 2 VCCz4 5V RL 1K 2 2 CIRCUIT DIAGRAM 60 3DB 3 SPECIFICATIONS IMPEDANCE LOW STANDARD VOLTAGE 4 5 V RANGE OF OPERATING VOLTAGE 1 5 V TO 10 V CURRENT DRAIN 0 5mA Max S N RATIO 40 db or more MAXIMUM SOUNE PRESSURE 120 db SPL 4 DIMENSION t h fm H i 7703 sl
5. PACR 0x80 PADDR 0x00 0 80 PBDDR Oxff PCDDR 0x0f delay function Main program starts here Unconditional true loop stats KS 9 dea data already available S on input of ADC d here Switches 0 01 ADCPTR 0xD00000 Switches 0x02 Similarly other infu p rts Ain4 AinS Ain equ by checking status of s 4 PAS PAG respecti witches 0x80 ADCPTR 0xD0000E Transfer logic 0 pulse at port PBO of the PI T Logic 0 pulses are v transfer to generate square wave to control the speed t Continue the process The motor Figure 6 1 Working of the software program This flow chart make the program very easy to understand and help the reader to elaborate the idea of this project for further development without any problem 6 3 Summary In this chapter the main software modules is explained which help in making decision that which sensor is chosen at a time to control th speed of the motor or any real world application The program is simple to dnderstand and the whole program code is present in Appendix CHAPTER 7 FUNCTIONAL TEST RESULT 71 Buffered Board Test Before using I O buffered board its initial testing is necessary by giving logic 0 and 1 pulses at the input port of the PI T and taken the output from the consecutive pin of the output port For example
6. when PAO switch is active the LED at the port PBO glows i e the data given at input port A is taken out from the port B Similarly other pins of the port and port B tested For testing program refer Appendix B 2 char switches switches is declared to take data from input po PACR 0x80 A Initialisation of the PADDR 0x0 PBCR 0x80 PCDDR 0x0f PBDDR Oxff While 1 Switches PADR Port A data transfer at variable switches PBDR switches Transfer switches data at port B Switches PCDR upper pins PC7 PC4 of Port C data is transfer at variable switches Switches switches gt gt 4 PCDR switches Transfer switches data atlower pins PCO of port This test is successfully completed and also the working of upper and lower port pins of port C of PI T is checked 7 2 Single input ADC Test Initially the testing is to be done on the single input AinO of the ADC for checking proper functioning of the ADC board A 5 V signal is given at the Ain 0 pin continuously and this input is transfer at variable f as shown in program below This analogue voltage is converted into binary 1 and note down from the port B of the PI T If a variable voltage is giver at the Amt then the output of the port B is changed according to the value of this variable analogue signal The changes at the port is easily seen by using the watch window option of the Embedded design software unsigned char f
7. 12 4 222 57 7 3 Multiple Input ADC Test 94 57 7 4 1 59 CHAPTER 8 PROJECT MANAGEMENT 8 1 1 60 8 2 Time Management 4 60 8 3 Summiary 840 64 CHAPTER 9 CONCLUSION AND FUTHER DEVELOPMENT 9 1 Introduction 8 65 9 2 Conclusion 8 82 4 65 9 3 Further Work And Development 66 REFERENCE gt 68 BIBLOGRAPHY 69 APPENDIX APPENDIX A 1 BlockDiagram of the FLIGHT 68K Board 70 APPENDIX A 2 specifications of the FLIGHT 68K BOARD 71 APPENDIX B 1 Program Code for Whole Flexible Development Platform 73 APPENDIX B 2 Program code for testing I O buffered board 76 APPENDIX Program Code for Testing Single Input o
8. 2l Figure 2 5 Square 23 Figure 4 1 68000 function code 29 Figure 4 2 Logical arrangements of the 68000 29 Figure 43 Connection of PC FLIG T 30 Figure 5 1 Voltage Amplifier Using Op Amp 741 34 Figure 52 Simple Voltage Sensor Cen 35 Figure 5 3 Graphical representation of output of Voltage 36 Figure 5 4 Switch Sensor i oe tere eso epa e tti dedo d etaed 37 Figure 5 5 LDR Resistance Vs Output Voltage Of light 38 Figure 5 6 Graphical representation of the light sensor output 00ssseeeereeen 39 Fig ure5 7 Sound Sensor Circuit 2 000 1 40 Figure 558 Exod VE ya EE 42 Figure5 9 Bus Expander 43 Figure 5 10 I O Buffered Board HE 45 Figure 5 11 Stepper Motor Controller 2 46 Figure 5 12 Timing Diagram of Different Modes of Stepper Motor 47 Figure 5 13 Timing Diagram of Segment and Index pulse 18 47 Figure 514 Decoder Used for Address 49 Figure 5 15 Experimental setup ofthe w
9. Shed Alarm The data sheet of LDR is present in Appendix H Since there is no light meter to measure the light intensity therefore graph is plotted between the resistance of the LDR and the Output Voltage by hit and trail method This resistance may not be exactly match with the actual light intensity The plot is shown in figure 5 6 D1 I AMA D1N750 2k 3 R3 GURPUT TO THE ADC OPAMP Light Sensor Circuit Figure 5 5 LDR Resistance in KOhms 27 22 1 20 2 15 3 10 2 1 92 1 71 1 6 1 04 Output Voltage In Volts 0 5 0 9 12 1 6 1 9 2 1 2 4 2 6 2 84 Table 5 1 LDR Resistance Vs Output Voltage Of light Sensor LDR Resistance Vs Output Voltage 9 5 2 5 i 2 B 1 5 Output Voltage gt 1 5 05 0 T T 0 10 20 30 LDR Resistance in K Ohms Figure 5 6 Graphical representation of the light sensor output 5 1 4 Sound Sensor The circuit diagram for simple sound sensor is shown in figure 5 8 in which the Op Amp is used only to amplify the output signal of microphone so that it easily controlled the motor The lower voltage signal cannot control the speed of the motor as the minimum input supply to the motor is 2 5 V This circuit works very well only when loud noises are present For the specifications of the micro phone refer Appendix This circuit gives very lessyoutput changes because of no
10. use The total descriptions of these commands are available in FLIGHT 68K user manual The line by line assembler accepts 68000 assembler language instructions and assembles them a line at time making program entry simple and quick Using the disassembler M68000 8 16 32 BIT MICROPROCESSORS USER S MANUAL MOTOROLA 3 1 may be disassembled from anywhere in memory The assembler source code may be displayed or printed out if a printer is connected There is also a C compiler available for the F68k The compiler replaces the monitor EPROM on the F68k microprocessor board and thesterminal window on the personal computer is replaced with a program called Embedded Development Studio EDS The Flight 68K includes 68681 Dual UART and 68230 Parallel Interface Timer enabling to learn about the 68K family peripherals and to apply the FLIGHT 68K to real control applications 7 The MC68230 provides 24 parallel input output lines plus a counter timer Access to these lines is by the 40 way I O connector which also links to the Switch Lamp Unit 4mm I O Module or to our Application Board which provides a wide range of ready built control applications There are two ports on the PI T used as inputs and outputs which are mapped mto the memory map starting at 800001 The basic addresses of these ports are given in table 4 1 PYT Port A address Port B address Data Direction Register 800007 Control Register 80000D 80000F Data Register 800011
11. 0x00 PBCR 0x80 PBDDR Oxff PCDDR 0x0f APPENDIX B 2 Program code for testing I O buffered board 680X0 Initial C Source File Created by Gulwinder Singh include PITH char PACRPTR 0x80000D char PADDRPTR 0x800005 char 0 80000 char PBDDRPTR 0x 800007 char PBDRPTR 0x 800013 char PADRPTR 0x 80001 1 char PCDDRPTR 0x 800009 char PCDRPTR 0x800019 define PACR PACRPTR define PADDR PADDRPTR define PADR PADRPTR define PBDDR PBDDRPTR define PBDR PBDRPTR define PBCR PBCRPTR define PCDDR PCDDRPTR define PCDR PCDRPTR char PCDDRPTR 0x 800009 char PCDRPTR 0x800019 define PCDDR PCDDRPTR define PCDR PCDRPTR main char switches Program code for testing I O buffered board PACR 0x80 PADDR 0x0 PBCR 0x80 PCDDR 0x Of PBDDR Oxff while 1 Switches PADR PBDR switches SwitcheszPCDR Switches switches gt gt 4 PCDR switches Port A data transfer at variable switches Transfer switches data at port B upper pins PC7 PC4 of Port C data is transfer at variable switches Transfer switches data at lower pins PCO of port APPENDIX B 3 Program Code for Testing Single Input of the ADC Board GULWINDER SINGH include PIT h void include PIT define ADC ADCPTR unsigned char ADCPTR 0xD0000 char PACRPTR 0x80000D char PADDRPTR20x800005 char PBCRPTR 0x80000F char PBDDRPT
12. 3 Data for selecting ADC Input Pin RS 232 a serial communication link between the PC and the 68000 it is a standard that describes method of serial signaling using a voltage that switches between a positive level for logic 0 and a negative level for logic 1 5 3 Bus Expander Bus Expander is designed as a prototype board for the connection with MC 68000 chip This board consists of all the 40 pins of 68000 microprocessor and connected with FLIGHT 68K board via 40 pin connector Figure 5 9 is the block diagram of this board which contains only pins of MC6800 used in this project The VPA Valid Peripheral Address and VMA valid Memory Address signals are used rather than DTACK Data Acknowledge because of not designing any wait state generation circuitry and also the zero wait sate time is less than the minimum access time for the ADC chip D8 D9 D10 D11 D12 D13 D14 D15 VMA Bus Expander Board Al A2 A3 A21 A22 A23 A20 AS Figure5 9 Bus Expander Board UDS VPA 5 4 Buffered Board The Buffered IO board is used to interface the MC68230 Peripheral Interface Timer PIT on the Flight 68K main board to external peripherals The board has 12 input pins PAO PA7 and PC4 PC7 and 12 output pins PBO PB7 and The logic value of the pin is displayed an LED next to it The input pins have a choice of signal source The input can either be set by
13. 741 Connection Diagrams Metal Can Package NON INVERTING INPUT 5 S OFFSET NULL 4 TL H 9341 2 Order Number LM741H LM741H 883 LM741AH 883 or LM741CH See NS Package Number H08C Dual In Line 5 0 Package TL H 9341 3 Order Number LM741J LM741J 883 LM741CM LM741CN or LM741EN See NS Package Number J08A M08A or NO8E is available per JM38510 10101 APPENDIX 2 DataSheet Of Op Amp 741 Ceramic Dual In Line Package OFFSET NULL IN IN JS OFFSET NULL NC NC TL H 8341 5 Order Number LM741J 14 883 LM741AJ 14 883 See NS Package Number J14A also available per JM38510 10101 also available per JM38510 10102 Ceramic Flatpak LM741W OUTPUT OFFSET NULL TL H 9341 6 Order Number LM741W 883 See NS Package Number W10A Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Note 5 LM741A LM741E LM741 LM741C Supply Voltage 22V 22V t22V r18V Power Dissipation Note 1 500 mW 500 mw 500 mW 500 mW Differential Input Voltage 30 30V 30V 30V Input Voltage Note 2 15 15 t15V 15V Output Short Circuit Duration Continuous Continuous Continuous Continuous Operating Temperature Range 55 O to 125 C 0 C to 70 C amp S C to 125 C 0 C to 70 C Storage Temperature Range 65 C to 150 C 65 C to 150 C 65
14. 800013 Table 4 1 68230 PI T addresses of F68k Furthemuser expansion may be gained by way of the male 64 way DIN41612 connector which provides access to the entire MC68000processor signal 68681 DUART Die MO STI FLT 68K Debug monitor H gt gt gt V 772777171222 Figure 4 4 FIGHT 68K An on board system reset switch is provided as are status LED s and fault switches which allow the simulation of hardware faults for student fault finding exercises for practice 16 bit microprocessor trainer designed to introduce students to the industry standard microprocessor for industrial control applications the Motorola 68000 CPU 4 3 Choosing language for programming In times past computer languages were classified into low level language assembler and high level languages e g COBOL FORTRAN ALGOL Assembler is related to the actual machine instructions that is it depends on the actual hardware One statement in high level language will xpand into many many assembler statements and is independent of the hardware 8 Assembler language is not standardized There is one assembler language for Z80 micro processor another for 68000 another for 6502 microprocessor etc C may be regarded as standardized assembler and shakes off its dependence on particular microprocessor C may be regarded as evolved from Assembler gt gt B written by Ken T
15. T Poster Presentation amp viva 8 Important Deadline date Initial Time Plan Final Time Plan Seminar presentation Report Submission and Poster presentation Figure 8 1 Initial and Final time plan Gantt chart 8 3 Summary This chapter includes the initial time set up by the author and the actual time spent on this project with reasons for time difference between the both Gantt chart CHAPTER 9 CONCLUSION AND FURTHER DEVELOPMENT 9 1 Introduction This chapter split into split into two sections the first is about what the project achieved and the conclusion surrounding this The second is about further work which has been carried out if the time allowed or if the work will be continue by somebody else 9 2 Conclusion The project describes the design and performance of th micro processor based robot controller The knowledge of the programming language C and hardware was very useful to carry out the project most of the problems encountered in the project is how to design the sensors used at the input port of the ADC The initial objective of using sensors of Lego Mindstorms and Logit is not fulfilled because after deep study in sensors it is concluded that all these sensors are designed according to their manufacturer companies software So the sensors used by author itself by which he gains valuable knowledge in the fascinating field of sensors actuators and Microprocessors The sensors circuit was tested a
16. The heart of the Flight FL T 68K is the MC68000 CPU and it has a 16 bit data bus and 24 bit address bus The system also incorporates a range of peripheral devices and is driven by a 1 OMHz clock The block diagram of the FLIGHT 68K is shown in Appendix 1 The FLT 68K is supplied with 16K bytes of RAM which is more than sufficient for most teaching requirements but is expandable to attotal of 512K bytes making it also suitable for larger scale applications Two RAM memory sockets accept 6264 8K 62256 32K or 551001 128K static RAM in pairs resulting in 16K 64K and 256K bytes respectively Two further auxiliary RAM sockets may also be used to accommodate these same devices resulting in a maximum RAM size of 512K bytes The most common configuration is by connecting the serial port of a personal computer to the F68k Figure 4 3 shows the setup between the F68k and a personal computer running a serial port terminal 68000 AC adapter PC 230 VAC RS23 2c serial nterface cable 68KMB 68000 CPU Connection to COM parton back of PC FLIGHT 68K Figure4 3 Connection of PC and FLIGHT Also as standard two 27256 32K EPROM are fitted containing the FLT 68K s monitor firmware This firmware comprises comprehensive monitor line by line assembler and dissembler The monitor program provided with the FLT 68K has 53 different commands which is invoked by a simple two letter code It is user friendly and easy to
17. While it s actual gain equation is given by the control function relationship as Vo Vin Rf Ri 1 A Ri RF Ri A is the gain of the Op Amp Refer Appendix Design and testing of the simple Voltage Sensor Switch Sensor Light Sensor and Sound Sensor is given below 5 1 Voltage Sensor Potentiometers are especially used for making angular measurement devices because most pots only turn approximately 270 degrees or so They are great for determining the angles of a robot arm Actually potentiometer cofiverts a mechanical input into electrical signal Potentiometer is used to design this voltage sensor In figure 5 2 resistance of a sensor is converted into a voltage by using potentiometer which is almost linear as shown in graph figure 5 3 5y R 10K ted utput to the C Simple Voltage Sensor Circuit Figure 5 2 Output of the The input supply of reference voltage sensor is tried to the position of the resistance of changes and voltage changes Output Voltage Pot Resistance in K Ohms 10 2 9 4 8 4 7 3 5 9 4 8 4 1 2 6 1 2 Output Voltage in Volts 5 1 4 7 4 2 3 6 3 0 24 2 1 13 0 7 Table 5 1 Voltage Sensor 5v is given as output of this taken according to pot As it varies the potentiometer accordingly output Resistance Vs graph is plotted in figure 5 3 Potentiometer pot resistance is noted aecording to the position of the pot PotResis
18. Y7 are the output pins of 3 8 decoder which are selected according to the status of the A B C pins El active low E2 active low and E3 active high are enable pins which are connected to the UDS ASS and A20 pins of MC68000 respectively A vu B 7420 V C Y2 Y3 E2 Y4 1 Y5 Y6 Y7 74138 _ lt VMA Figure 5 14 Decoder Used for Address Decoding 5 7 Experimental setup of the Flexible Development System The hardware connection of all the blocks discussed abov is given in the figure 5 15 which represents the flexible development platform for interactive robots Single sensor is selected at a time by sending 1 A2 address line data of MC68000 onto selection pins 0 1 and A2 of ADC board as shown in table At the same time A21 A22 A23 address line also selected the output Y6 of the 3 8 decoder which is latched and transfer its data at VPA If the microprocessor is ready to take data then it send a signal from VMA to the CS which select the ADC chip Then the physical parameters of the sensor is started to read by the processor and control the speed of the stepper motor via the port B PBO pin of PI T MC68230 which is defined as output port As no wait state generation circuitry is designed so VPA and VMA signals are used rather than DTACK for synchronous data transfer The zero wait state time is also less than the access time of the ADC chip Access time is not a ADC conversio
19. and Disadvantages of sensors are also discussed Details of Light sensor Touch sensor and Rotation sensor used in Lego Mindstorms and DCP Logit Sound sensor is given for the reader to work further on these sensors Finally the types of servo and stepper motor used in the robots with its advantages and disadvantages is described CHAPTER 3 RESEARCH 3 1 Literature search For the literature search of this project online databases INSPEC IEEE and relevant journal articles were searched Various journals available in Learning Resource Centre of University of Hertfordshire were also referred Motorola web site was searched for datasheets relating to the 68000 microprocessor and application notes that were relevant to the project including Program Interface Timer 68230 and memory mapping techniques General searches were also conducted on the World Wide Web for any relevant information Prior to the starting of this project significant research had been undertaken to find out any previous work done on this topic The results of this research provided the foundation upon which this project is built The basic idea was taken from Lego Mindstorm robot which is commercially available for toys but this robOtus strictly used for only three sensors and one motor 32 Hardware research During Literature search no relevant information was found on online database INSPEC about the sensors and motors available in the market Also search was cond
20. is given here for the reader or designer who wants to work anymore on these Sensors The circuit shown in figure 2 3 is used to interface these sensors other than Lego robot 15 D1 D3 05 output D2 D4 D6 Figure 2 3 General purpose analogue interface circuit This circuit should work as a more general purpose analog interface The Op amp provides gain 1 R2 R3 and could be used where the input signal is too small for the 0 to 5 volt range The is an auxiliary output from the circuit to provide about 10mA of power to operate other sensor electronics NPN transistor is added to get more linear interface Touch Sensor For a touch sensor input the intetface circuit has a 10 000 ohm resistor pulling up the input to 5V The voltage on the input i converted to an internal RAW value in the range 0 to 5V 1023 Depending on the sensor type the RAW number is converted into the number we see in the program Test Panel or Vi w In the case of the touch sensor it is converted into a Boolean 1 or 0 values Light Sensor For a light sensorthe interface circuit uses a 120 ohm resistor to pull up the input to about 8V to power the red LED for about 3ms and then looks at the sensor voltage for a 0 1ms During the 0 1ms time the sensor is read just like the touch sensor The light values are calculated Light 146 RAW 7 within the range of 0 to 100 The table below shows the percent Pct values of light with the
21. memory devices would have to be fast enough to have data ready when the processor expects it and peripherals fast enough to act on data before the processor removes it from the bus There are three signals called function codes and FC2 dat are output from the 68000 The functions codes provide a means of determining what state the 68000 is currently in as shown in Figure 4 1 Three of the eight states are marked undefined reserved which tells us that these states may be reassigned in the future versions of the 68000 The function codes and the current address on the bus are considered valid when the address strobe AS is asserted active low by the processor Function Code FCO Meaning 0 0 0 Reserved ervisor data being acc program being accessed Figure 4 1 68000 function codes The 68000 has 64 pins arranged in nine groups as shown in Figure4 2 Each of these groups is labeled by the function of pinsut performs Voc 2 GND 2 CLK A23 Al D15 D0 ASYNCHRONOUS BUS PROCESSOR CONTROL STATUS Min BUS PERIPHERAL ARBITRATION CONTROL CONTROL SYSTEM INTERRUPT CONTROL CONTROL Figure 4 2 Logical arrangements of the 68000 pins 6 4 2 FLIGHT 68K Board The FLIGHT 68K is designed by the Flight Electronics to provide the educational training to the students or programmer in the world of 16 32 bit microprocessors by the way of the very popular Motorola MC68000
22. useful information regarding the hardware part of the flexible development platform All the parts aresdiscussed in detail which are followed by the experimental setup of this project The working of all the elements ADC Bus Expander I O buffered board Stepper motor controller Address decoder is described step by step and finally the whole setup of this platform is specified for easy understanding of the subsequent of the readers CHAPTER 6 SOFTWARE DESIGN 6 1 Introduction Crossware www crossware coom a leading embedded software tools developer has released a suite of software for the FLT 68K Microprocessor Trainer kit Crossware Embedded Development Studio includes a re locatable macro cross assembler source level simulation and source level debugging and comprehensive documentation It contains a sophisticated ANSI C compiler with the features of Windows 95 and Windows NT4 0 to provide a development environment 10 The advanced training suite of FLT 68K used in the project has following feature 10 gt Optimising ANSI C compiler and libraries Advanced Edition only gt Relocatable cross assembler linker and library manager Source level simulator to debug without hardware gt Source level serial port debugger to debug with FLT 68K Microprocessor Trainer board via the PC serial port gt EPROM s containing the Crossware debug monitor to replace the existing FLT 68K monitor Embedded Developmen
23. 8 35 5 1 3 36 5 1 4eSourld Sensor 37 5 2 Analogue to Digital Converter 38 5 3 41 5 4 I O Buffer Board 42 5 5 Stepper Motor Controller Board 43 5 6 Address Decoding 45 5 7Experimental Setup of the Flexible Development Blat form 47 5 8 49 CHAPTER 6 SOFTWARE DESIGN 6 1 45 50 6 2 Software Program Byo 4 51 6 3 2 55 CHAPTER 7 FUNCTIONAL TEST RESULT 7 1 VO Buffered Test 4 2 1 56 7 2 Single Input ADC
24. C to 150 C 65 C to 150 C Junction Temperature 150 C 100 C 150 C 100 C Soldering Information N Package 10 seconds 260 C 260 C 260 C 260 C J or H Package 10 seconds 300 C 300 C 300 C 300 C M Package Vapor Phase 60 seconds 215 C 215 C 215 C 215 C Infrared 15 seconds 215 C 215 C 215 C 215 C See AN 450 Surface Mounting Methods and Their Effect on Product Reliability for other methods of soldering surface mount devices ESD Tolerance Note 6 400V 400V 400V Electrical Characteristics note ae 0 zum LM741A LM741E LM741 LM741C SCH Min Typ Max Min Typ Max Input Offset Voltage Ta 26 C Rs 10 1 0 20 Rs 500 Tamin TA Rs 500 Rs 10k Average Input Offset Voltage Drift Input Offset Voltage Ta 25 C Vs 20V 415 415 my Adjustment Range Input Offset Current um lt Average Input Offset Current Drift Input Bias Current CUT EE 25 C ees Input Resistance TA 25 m 20V aS de aa 03 20 zu MILL Vs 20V muVotapRage Tamo Tool X cure qo xps c Large Signal Voltage Gain TA 25 C RL 2 2k Vs 20 15V Vs 15V Vo 10 50 Tamin TA RL 2k0 Vg 20V Vo 15V Vg 15 10V 25 Ve 5V Vo t2V APPENDIX I Data Sheet Of LDR Used in Light Sensor PHOTOCONDUCTIVE CELL VT400 Series
25. DDR PADDRPTR define PADR PADRPTR define PBDDR PBDDRPTR define PBDR PBDRPTR define PBCR PBCRPTR define PCDDR PCDDRPTR define PCDR PCDRPTR Program Code for Whole Flexible Development Platform void delay int del define delay function int f g for f 0 f lt del main unsigned char f char Switches include PIT Senor is selected according to status of the switch of the port A of PI T while 1 switches P ADR if switches 0x01 A data of PI T ADCPTR 0xD00000 ADC input AO works else PBDR 0 if switches 0x02 port A data of PI T 0 000002 ADC input Al works Else PBDR 1 if switches 0x04 port A data of PI T ADCPTR 0xD00004 ADC input A2 works if switches 0x08 A data of PI T ADCPTR 0x 000006 ADC input A3 works if switches 0x10 port A data of PI T ADCPTR 0xD00008 input 4 works Program Code for Whole Flexible Development Platform if switches 0x20 A data of PI T ADCPTR 0x DOOO00A ADC input A5 works if switches 0x40 port A data of PI T ADCPTR 0xD0000C ADC input A6 works if switches 0x 80 port A data of PI T ADCPTR 0x DOOOOE ADC input A7 works ADC 0x0 initial data of ADC port delay 10 f ADC PBDR 1 High level signal at port B of PI T delay f 1 PBDR 0 llow level signal at port B of PI T delay 4 void include PIT PACR 0x80 PADDR
26. R 0x 800007 char PBDRPTR 0x 800013 char PADRP PR 0x 800011 char PCDDRPTR 0x 800009 char PCDRPTR 0x 800019 define PACR PACRPTR define PADDR PADDRPTR define PADR PADRPTR define PBDDR PBDDRPTR define PBDR PBDRPTR define PBCR PBCRPTR define PCDDR PCDDRPTR tdefine PCDR PCDRPTR char PCDDRPTR 0x 800009 char PCDRPTR 0x 800019 define PCDDR PCDDRPTR define PCDR PCDRPTR void delay int del int fg for f 0 f lt del f main unsigned char f Program Code for Testing Single Input of the ADC Board PBCR 0x80 configure the PI T to work with the Buffered I O Board PBDDR Oxff While 1 ADC 0x0 Mnitially transfer 0 0 data at ADC input delay 10 f ADC Assign the ADC input data to variable F PBDR f Transfer this data on the port B of the PI T delay 10 APPENDIX C Registers of PI T 680230 Register select bits RSS RS4 RS3 RS2 RSI RESISTOR Register Description Mnemonic 0 0 0 0 0 PGCR 0 0 0 0 1 PSRR 0 0 0 1 0 PADDR 0 0 0 1 1 PBDDR 0 0 1 0 0 PCDDR 0 0 1 0 1 PIVR 0 0 1 1 0 0 0 1 1 1 PBCR 0 1 0 0 0 PADR 0 1 0 0 1 PBDR 0 1 0 1 0 PAAR 0 1 0 1 1 PBAR 0 1 1 0 0 PCDR 0 1 1 0 1 PSR 1 0 0 0 0 TCR 1 0 0 0 1 TIVR Port general control register Port service request register Port A data direction register Port B data direction register Port C data direction register Port interrupt vector register Port A co
27. That is the input stimulus is converted by the sensor into output energy without the need for an additional power source These are mainly rely on a locally generated or natural source of radiation light from the sun or an available energy field gravity Passive sensors can exploit EM radiation of any frequency in which some natural phenomenon radiates This can extend from ELF Extreme low frequency below 3x103Hz up to gamma rays above 3x1019Hz They can exploit acoustic energy vibration from infrasound frequencies less than1 Hz from earthquakes or explosions up to the ultrasound 14 2 1 3 Sensor Output Values An important part of building a robot is th incorporation of sensors Sensors translate between the physical world and the abstract world of Microcontrollers Sensors help translate physical world attributes into values that the computer on a robot can use The translation produces some sort of output value that the Microcontroller can use The output of a self contained sensor or of the remote amplifier of Component sensing system is either digital or analogue 1 Digital Sensors A digital oumut ie more commonly called a switched output A switched output has only two states and off On and off commonly refer to the status of the load that the sensor output is controlling The load might be an indicator light an audible alarm a clutch or brake mechanism a solenoid valve or actuator or a sw
28. UNIVERSITY OF HERTFORDSHIRE Faculty of Engineering amp information science MSc in ELECTRONICS DIGITAL SYSTEMS Project Report A FLEXIBLE DEVELOPMENT PLATFORM FOR INTERACTIVE ROBOTS Gulwinder Singh April 2003 I certify that the work submitted is my own and that any material derived or quoted from the published or unpublished work of other persons has been duly acknowledged ref UPR 17 1 section on cheating and plagiarism KEE E EE 5 ABSTRACT This report is a detailed description of the work carried out in order to design a Motorola 68000 microprocessor based flexible development platform for interactive robots in term of its applications and usability Due to tremendous development in sensor technology the robots become more flexible and versatile by applications of their sensors As Lego Mindstorms allows to build a robot that works in a specific environment but the main objective of this project is to develop an application that allows interaction with a robot from the outside world where motors are controlled according to the physical parameters of the different sensors easily The aim of this report is to demonstrate the main function and application of the interactive robot by using embedded chips and c program The reasons for choosing a MC68000 application board and C language to develop this system are included in this report Various work stages and development of the project is discussed Also include
29. able that can be measured 1 40F 100F in a thermometer Output range can be defined similarly Linearity The closeness of the calibration curve to a specified straight line 1 theoretical behavior least squares fit Monotonicity A monotonic curve is one in which the dependent variable always increases or decreases as the independent variable increases Hystheresis The difference between two output values that correspond to the same input depending on the trajectory followed by the sensor 1 magnetization in ferromagnetic materials Backslash hystheresis caused by looseness in a mechanical joint Dynamic Characteristics The sensor response to variable input is different from that Exhibited when the input signals are constant the latte is described by the static characteristics The reason for dyn mic characteristics is the presence of energy storing elements Inertial masses inductances Capacitanees electrical thermal Dynamic characteristics are determined by analyzing the response of the sensor to a family of variable input waveforms Impulse step ramp sinusoidal white noise 2 s x i 3 x me time time Analog Step Ramp 2 5 S 3 S E E x Sinusoidal Ve Noise Fig 2 4 Different Types of Signals 2 1 5 Advantages and Disadvantages of the sensors Advantages Passive Active Low power requirement Long range operation Long life possible Simple principle
30. c460 Components 3 http www legomindstorms com 4 Kleitz William Digital and Microprocessor Fundamentals 2 Edition 1997 5 H R Everett Sensors for Mobile Robots Theory and Application A K Peters Ltd 1995 APPENDIX A 1 BLOCK DIAGRAM OF THE FLIGHT 68K BOARD Clock 10MHz 68 Fm Generator cru Digital UO PORT A EPROM 32K Bytes EIE Upto 128K Bytes RS232 Interface 68681 DUART RAM 16K Bytes Auxiliary Upto 256 Bytes Connector Expansion Connector Auxiliary RAM 16K Bytes Upto 256K Bytes 49V Power Supplies Block Diagram of the FLIGHT 68K APPENDIX A 2 SPECIFICATIONS OF THE FLIGHT 68K BOARD FLIGHT 68K User Manual APPENDIX L APPENDIX L FLIGHT 68K SPECIFICATION PROCESSOR Motorola MC68000P10 CLOCK SPEED 10MHz EPROM up to 128k bytes RAM up to 256k bytes AUXILIARY MEMORY RAM up to 256k bytes PERIPHERAL EXPANSION Processor Bus POWER 9 volts unregulated at 700mA Consumption may vary if memory configuration altered or expansion card added SYSTEM FIRMWARE 64k bytes of EPROM comprising comprehen sive monitor line assembler disassembler 28 system calls INPUT OUTPUT CAPABILITIES Serial I O Two RS232 channels software selectable baud rates of 75 110 150 300 600 1200 2400 4800 9600 and 19200 baud Default format S data bits no parity one stop bit DUART Auxiliary I O lines Input 4 Characteristics Input High Voltage 2 0V Input Low Volta
31. d Narrow gaps between objects or short times between sensing events must also be considered when verifying that a sensor s response is fast enough for the application 3 Static characteristics These describe the device performance at room conditions with very slow changes in the measurand and in the absence of any mechanical shock Static characteristics include 3 Linearity A sensor is said to be linear when the constant of proportionality has the same value with in the whole measurand range and then exhibits increasing deviation from straight line linearity Accuracy Itis the capacity of a measuring instrument to give RESULTS close to the TRUE VALUE of the measured quantty Precision The capacity of a measuring instrument to give the same reading when repetitively measuring the same quantity under the same prescribed conditions Precision implies agreement between successive readings NOT closeness to the true value Precision is related to the variance of set of measurements Precision is a necessary but not sufficient condition for accuracy Two terms closely related to precision Repeatability The precision of a set of measurements taken over a short time interval Reproducibility The precision of a set of measurements but taken over a long time interval or Performed by different operators or with different instruments or in different laboratories Input range The maximum and minimum value of the physical vari
32. d is a methodical description of the construction and testing of the sensors involved in the project and finally a conclusion which discusses all the important aspects of this successfully completed project Any subsequent reader should be able to gain valuable knowledge from this report Acknowledgements During this project there have been many people that have given me their valuable time and support so I would like to give them special thanks The help of all such people is gratefully acknowledged In particular the following people at the University of Hertfordshire deserve my gratitude First of all I would like to express my gratitude to Dr David Lee Project Supervisor for his invaluable devotion and supervision throughout the period of the project His guidance and considerable experience are greatly appreciated His advise and continuous support had certainly helped me particularly during the difficulties are encountered Mr Tony Crook Technical Manager for assisting with many practical decisions and providing all the components which I required Tor project without any delay Mr Ian Munro researcher at the University of Hertfordshire for advice and assistance on the project Mr Stephen Passmore Technician for providing assistance with access to the microprocessor laboratory and making available the necessary equipment when needed Finally this project is dedicated to my family who provides me a opportunit
33. diatign Target of Interest Antenna Reflected Radhatio NT ex Re Figure 2 3 Principle of the sensor The source of radiation is fed to a transmit antenna tuned to the characteristics of the target sometimes Matched to the impedance of the medium to maximise coupling and efficiency and radiated by a directional antenna to increase the energy on the target These radiations strike at the target of interest and emit back from which a small percentage of power enters the receiver antenna and converted into the electrical signal which amplified and detected according to the application requirement 14 2 1 2 Types of sensors Mainly there are two types of sensors Active Sensors and Passive Sensors ACTIVE SENSORS Active sensors require the application of external power for their operation This excitation signal is modified by the sensor to produce an output signal Some sensors also called semi active sensors which use an excitation signal generated by or radiated from a source that is not coincident with the sensor Active sensors are restricted to frequencies that can be generated and radiated fairly easily This excludes part of the far infrared above 3 1012 2 parts of the ultraviolet band and the gamma ray region These frequency ranges of sensors are used for high commercial applications like Satellite communication 14 PASSIVE SENSORS Passive sensors directly generate an electric signal in response to a stimulus
34. drawback is easily eliminated as discussed in the further development Much of the time is devoted in the study of the different types of the sensors which disturbed the time plan of the project By giving lots of effort in this project this project is completed on time 9 3 Further Development A lot of necessary groundwork is to be done Therefore if anybody want to continue this project they would already have a good understanding of what required and what problem have to be solved by studying this project report There are many ways by which further modification of this project is possible such as Sensors The high quality may be used at the input of the ADC which give the quick response as the environmental condition changes makes the system more flexible because sensors arethe only devices that supply external environmental information to the robotic system gt Address Decoding For interfacing with the Microprocessor address decoding is to be done with the advance technology of FPGA Field Programmable Logic Array PLA Programmable Logic Array and PAL Programmable Array Logic instead of the address decoder These devices share the random logic elements and ROM based decoder properties which gives optimum design from the point of view of the speed and provides flexibility and compactness at the cost of a slightly slower speed and a restriction on the number of variables that can be handled economically Multiple out
35. e motor is not too great open loop control is usually us d to control the motor Stepper motors are used in disk drive head positioning plotters and numerous other applications But for servomotor they require analogue feedback control systems of some type Typically this involves a potentiometer to provide feedback about the rotor position and some mix of circuitry to drive a current through the motor inversely proportional to the difference between the desired position and the current position Servo motors are used in radio control airplanes to control the position of wing flaps and similar devices Stepper motor is chosen for this project because of the availability of stepper motor control circuit in the laboratory of University of Hertfordshire designed by research students which saves time to concentrate on other aspects of the project But its advantages and disadvantages are also considered before using this motor which are discussed below Advantages 1 The rotation angle of the motor is proportional to the input pulse 2 The motor has full torque at standstill if the windings are energized 3 Precise positioning and repeatability of m vement since good stepper motors have an accuracy of 3 5 of a step and this error is non cumulative from one step to the next 4 Excellent response to starting stopping reversing 5 Very reliable since there are no contact brushes in the motor Therefore the life of the mot
36. egins the next cycle DTACK has to be generated a certain time after the beginning of a valid memory access timer supplied by the system designer The asynchronous bus therefore allows the 68000 to be used with slower memory devices peripherals than would otherwise be possible As in the 68000 synchronous bus control group of signals VPA VMA E are not needed because all data transfer may take place asynchronously But the synchronous bus control group simplifies the interface between the 68000 and peripherals designed for use with the older 8 bit synchronous bus microprocessors like 6800 For synchronous data transfer three control signals Valid peripheral address VPA Valid memory address VMA and Enable E VPA This indicates that a Synchronous bus cycle is requested by the external peripheral When the processor recognizes that VPA has been asserted it initiates a synchronous data transfer by means of its VMA and E control signals VMA The active low valid memory address signal from the 680informs the peripherals that there is a valid address on the address bus The assertion of VMA by CPU is a response to th assertion of VPA by an addressed peripherals E The enable output from the 68000 is a timing signal derived from the 68000 s own clock input One clock cycle is equal to ten 68000 clock cycles and it is non symmetric that is low for six clock cycles and high for four With a synchronous bus
37. else PBDR 1 if switches 0x04 port A data of PI T PA2 switch active only ADCPTR 0xD00004 ADC input A2 works if switches 0x08 port data of PI T PA3 switch active only 0 000006 ADC input works if switches 0x10 A data of PI T PA4 switch active only ADCPTR 0xD00008 ADC input A4 works if switches 0x20 A data of PI T PAS switch active only ADCPTRZOxD0000A ADC input A5 works if switches 0x40 A data of PI T PA6 switch active only ADCPTRZO0OxDO0000C ADC input works if switches 0x80 port A data of PI T PA7 switch active only ADCPTRZOxDOOO0E ADC input 7 works ADC 0x0 hnitial data of ADC port delay 10 f ADC PBDR 1 High level signal at port B of PI T delay f PBDR 0 Low level signalat port B of PI T delay f Testing is finished successfully and all he sensors are worked Switches at the port A of PI T easily controlled the one input afa time the output waveform at the PBO pin of the port B is shown in figure The maximum voltage of 4 9V is given by the analogue voltage sensor Ww LI GND 1 5 msec Figure 7 1 Output waveform at Port B by Voltage sensor The speed of the motor is controlled by the generation of the square waveform 7 4 Summary The final testing of individual elements and the whole set up is included in this chapter Step by step testing of all the modules helped to successful
38. equivalent Boolean and RAW outputs Rotation Sensor The interface for the Rotation sensor looks just like the Light sensor About 8V is applied for 3ms and then a voltage is read while 5V is applied through a 10 000ohm resistor for 0 1116 The sensor only outputs 4 analogue values of 1 8v 2 6v 3 8v and 5 1v Each voltage corresponds to 22 5 degrees of rotation so there are 16 counts per rotation The table 2 1 below shows the percent Pct values of rotation as used by the light sensor with the equivalent Boolean and RAW outputs 4 Volts Raw Sensorohms Light Touch 0 0 0 0 1 1 1 225 2816 1 1 6 322 4587 100 1 2 2 450 7840 82 l 2 8 565 12309 65 0 3 8 785 32845 34 0 4 6 945 119620 11 0 5 0 1023 Inf 0 0 Table 2 1 Summary Input Table 4 DCP Sound Sensor Sound sensor of DCP series ordered from the Commotion group which is a mail order company specializing in the supply of Science Technology and Primary School Products for using in this project DCP also provides Adapter Lead which allows connecting all the DCP sensors with Lego Mindstorms robots as well So many experiments conducted on this sound sensor to find the function of five pins of this sensor but no information found for its internal circuitry even after contacting support group of DCP micro sensors So author decided not to take this sensor as input for his system The brief description of this sensor pin out socket as viewed from outside is given for reader who wants to con
39. f the 68000 microprocessor and Program Interface Timer MC68230 CHAPTER 5 HARDWARE DESIGN 5 1 Design and testing of the Sensors The purpose of the sensor subsystem is to enable the robot to have some appreciation of its physical surroundings A broad range of sensors is available for practical use but it is found that most of the sensors designed by Robotics companies are designed according their software specifications For example DCP sound sensor has Micro sense identification input at pin number 5 see section 2 2 to differentiate from other sensors in their software This signal is used to identify sensors So for this project decision is made to design simple sensors using suitable components with operational amplifier 741 An operational amplifier IC is a solid state integrated circuit that uses external feedback to control its functions It is one of the most versatile devices in all of electronics The data sheet and pin specification of Op Amp 741 is given in Appendix 6 This Op Amp has so many Linear and Non linear applications such as differential amplifiers log amplifiers comparators and oscillators precision rectifier etc The designs of sensors described below are using simple application of Op Amp which Voltage Amplifier The Voltage amplifier is shown in figure 5 1 Figure 5 1 Voltage Amplifier Using Op Amp 741 Its ideal transfer function ideal gain equation is given by Vout Vin Rf Ri Ri
40. f the ADC Board 78 APPENDIX C Registers of PI T 680230 80 APPENDIX D Stepper Motor Board Circuit Diagram 8l APPENDIX E Buffered Board Internal Circuit Diagram 82 APPENDIX F Bus Expander Board Internal Circuit Diagram 83 APPENDIX G 1 Board Internal Circuit Diagram 84 APPENDIX 6 2 ADC Board Internal Cireuit Diagram 85 APPENDIX HI Connection Diagram Of Op Amp 741 86 APPENDIX H 2 Data Sheet Of Op Amp 741 87 APPENDIX I Data Sheet Of LDR Used in Light Sensor 88 APPENDIX J Data Sheet Of Microphone Used in Sound Sensor 89 APPENDIX Practical laboratory set up of the project 90 LIST OF FIGURES AND TABLES Figure LI RCX LEGO Brick iss ecc exec Eegen ee Pee 3 Figurel 2 Specified diagram of all the blocks of the project system 6 Figure 2 1 Some types of Energy forms converted by the Sensots 1 Figure 2 2 Principle of the Sensor sre ere nete e 10 Figure 2 3 Different TypesSignals EN 10 Figure 2 4 General purpose analogue interface 9 19 Figure 2 5 Function of pins of DCP 22 1 2 12
41. find most robots working for people in factories warehouses and laboratories In the future robots may show up in other places our schools our homes even our bodies Robots have the potential to change our economy our health our standard of living our knowledge and the world in which we live As the technology progresses we are finding new ways to use robots Each new use brings new hope and possibilities but also potential dangers and risks The Robot in this project means any kind of control machine for example transport machine for product line robot arm in car doing painting welding loading and unloading inspection and assembly 1 2 Project Background The objective ofthis project is to design a controller to control the sensors and actuators motors on a robot by interfacing with MC68000 which is connected with PC via RS232 This means any other computer with an RS232 interface will be able to control a robot using MC68000 There is a similar project called Lego Mindstorms Robots from which I take a basic idea for my project This system has limited inputs and also used expensive components like sensors connectors and motors So many students were working on this Lego Mindstorms robot but nobody tried to make their own flexible system especially using MC6800 therefore this design is tried to achieve in this project The brief description of this project is necessary before starting this project Actually M
42. ge 0 8V Input Leakage Current Vin O to Vcc 100A 10uA Output 6 Characteristics Min Max Se Output High Voltage excluding Open collector o p s Ioh 400uA 2 4V Output Low Voltage 2 4mA DAN L 1 APPENDIX A 2 continue SPECIFICATIONS OF THE FLIGHT 68K BOARD FLIGHT 68K User Manual Peripheral Interface Timer PI T I O Lines Port A PAO PA7 8 lines Port B PBO PB7 8 T O lines Port C PCO PC7 8 I O lines H1 H3 2 handshake inputs H2 H4 2 handshake I O lines Characteristics Min Input High Voltage Vss 2 0V Input Low Voltage Vss 0 3V Input Leakage Current Vin 0 5 25V Hi H3 Hi Z Input Current Vin 0 4 2 4v H2 H4 PAO 7 PBO 7 0 1mA 7 Output High Voltage load 150uA Vcc min H2 H4 PAO 7 PBO 7 Vss 2 4V load 100uA Vcc min 7 Vss 2 4V Output Low Voltage load 2 4mA Vcc min All Outputs Max Vss 0 8V 10uA 1 0mA 20uA 0 5V APPENDIX B T Program Code for Whole Flexible Development Platform CREATED BY GULWINDER SINGH void include define ADC ADCPTR ADC pointer defined define ADCI ADCIPTR unsigned char ADCPTR unsigned char ADCIPTR char PACRPTR 0x80000D char PADDRPTR 0x800005 char 0 80000 char PBDDRPTR 0x800007 char PBDRPTR 0x800013 char PADRPTR 0x 80001 1 char 0 800009 char PCDRPTR 0x800019 define PACRPTR define PA
43. gn This chapter presents the software details used in this project Chapter 7 Functional test results This chapter includes the testing and troubleshooting of various circuits used for interfacing with MC68000 and the experimental seftip of the whole system Chapter 8 Project management It consists the time management for successful completion of the project with the omparison of the initial and final time plan Gantt chart Chapter 9 Conclusion and Further development It contains all vital observations and conclusions of the project and some recommendations are also suggested for future development of this project 1 6 Summary This chapter includes the project background and the main aims and objectives of this project An overview of what a project system consists of follows with some typical application and finally the summaries of chapter organisation of this report are stated CHAPTER 2 SENSORS AND MOTORS 2 1 Introduction Thisychapter covers an introduction to basic of the sensors and motors and is not required reading for specialists in the theory of sensors fundamentals transducer is a device that converts input energy into output energy the latter usually differing in kind but bearing a known relationship to input Sensors form a small subset of the group of transducers and are defined as follows A sensor is a transducer which is capable of converting a physical non electrical input quan
44. hole system 50 Figure 6 1 Working ofthe software program 57 Figure 7 1 Output waveform at Port by Voltage 61 Figure 8 1 Initial and Final time plan Gantt chat 66 Table 2 1 Summary Input Table gm mee Mee 20 Table 4 1 MC68230 PI T addresses 68 31 Table 5 1 Output of the Voltage 2 202 2 1 36 Table 5 1 Analogue Signal Converted into Discrete Values 4 Table 5 2 Data for selecting ADC Input 2 2 42 Table 5 3 Address Decoding Table 48 Table 8 1 Time table of the important steps of Uheproiect cee 63 CHAPTER 1 INTRODUCTION 1 1 Preview Today most robots designed to be a helping hand They help people with tasks that would be difficult unsafe or boring for a real person to do alone At its simplest a robot is machine that can be programmed to perform a variety of jobs which usually involve moving or handling objects Robots can range from simple machines to highly complex computer controlled devices The robots of the movies such as C 3PO and the Terminator are portrayed as fantastic intelligent even dangerous forms of artificial life 9 However robots of today are not exactly th walking talking intelligent machines of of movies stories and our dreams Today we
45. hompson in 1970 for PDP 7 gt gt BCPL written by Martin Richards gt gt written by Dennis M Ritche 8 Nowadays people rarely use assembler any more Nearly all the chip manufacturers provide a C compiler for the chip they manufactured The C language was chosen o program the MC68000 as it is one of the most popular and powerful high level language Consideration was given to assembly language because it is more efficient in terms of code but ie more complex for programming C had many advantages over assembly language for this application Specific knowledge of the microprocessor instruction set is not required a basic knowledge of the MC68000 memory structure is desirable but not essential Programming and test time is reduced therefore increasing efficiency Programs take a formal structure and can be split into separate functions Details of register allocation and addressing of the various data types is managed by the compiler The ability to combine variable names with specific functions helps to improve readability and program construction C libraries contain many standard routines It can be compiled on a variety of computers The C language is very portable code can be quickly adapted for another processor for future development 3 4 Summary This chapter highlights the reasons for choosing MC68000 FLIGHT 68K training board and C language for programming with the brief description o
46. igital codes be used in various communications systems The ability to convert analogue signals to digital and vice versa is very important in signal processing The objective of an A D converter is to determine the output digital word corresponding to an analogue input signal Different types of the ADC are used as per the applications Main types of A D converters are VV VV WV Details on these ADC can be finding from any basic Electronics book The ADC used in this project is available in microprocessor which is designed by Research Students Study and testing refer chapter 7 of this board is very necessary before using 0 0195 0 0391 0 0586 0 0781 0 0977 Table 5 2 Analogue Signal Converted into Discrete Values Successive Approximation Register SAR Dual slope integrating Charge balancing Flash Converter Sigma delta Converter Integrating ADC E 92 N basic block diagram of ADC is shown in Figure 5 8 in which ADCBOARD DO DI Ain D2 Ain D3 Ain2 D4 Ain3 D5 Ain4 Figure 5 8 ADC Board Ain0 Ain are the input pins and D0 D7 are the output pins CS is the active low chip select pin which takes signal from VMA Valid Memory Address to active the ADC To select single input from the eight inputs binary data is given on the AO Al A2 pins as A1 A2 Input Pin Selected shown below 0 0 0 0 1 1 1 1 pe Or E ka E Table 5
47. indstorms is the name of a product line sold by the Lego group that is suggested for children above 11 years old INFRARED COMMUNICATIONS PORT SESSOR INPUTS LIGHT SENSUR TOUGH SENSOR MOTOR OUTPUTS LCD DISPLAY PANEL E HIGH EFFICIENCY MOTORS Les f Figure 11 RCX LEGO Brick The LEGO MINDSTORMS Robotics Invention Systems RIS is a powerful new technology It includes a programmable microcomputer called Robotics Command System RCX which is built into a LEGO brick and able to execute the programs downloaded from a computer The RCX Robotics Command System is a programmable LEGO brick It has three sensor input ports three output ports and four control buttons an LCD display and an infrared transmitter as shown in figure 1 1 It also has a microprocessor to process programs internal memory to store firmware and programs and a built in speaker to produce beeps and tones The lightssensor temperature sensor and touch sensors provide inputs to the RCX from the environment The RCX can then process the data to control the motors turn on off or forward reverse The Sensors motors and other components included in combination with the LEGO bricks allow users to build a blinding array of clever devices User can construct and program robots in such a way that these robots can be trained to move act and think like their own 1 This smart brick can
48. ironmental disturbances This minimum depends on the sensor design the sensor environment and the signal processing scheme used to decode the sensor s time varying electrical output If the minimum detectable measurand is low then the resolution is high Bandwidth A sensor with high bandwidth can change its output to follow fast high frequency variations in the input For measurands that change slowly such as the temperature of a large liquid tank bandwidth may not be important For other applications such as scanning shape or vibration sensors bandwidth may be the most important figure of merit Response Time Every sensor is specified for its response time The response time of a sensor or sensing system is the maximum amount of time required to respond to a change in the input signal e g a sensing event It is the time between the leading edge and trailing edge of a sensing event and the change in the sensor s output With a switched output the response time is the time required for the output to switch from off to or from to off These two times are not always equal With an analogue output the response time is the maximum time required for the output to swing from minimum to maximum or from maximum to minimum Again these two times are not necessarily equal Response time is important when detecting high speed events and becomes quite critical when detecting small objects moving at high spee
49. itching relay The load might also be the input circuit to a timer counter programmable logic controller or computer 2 Analogue Sensors An analogue output is one that varies over a range of voltage or current and is proportional to some sensing parameter For example the output of an analogue photoelectric sensor is proportional to the strength of the received light signal Sensors with analogue outputs are useful in many process control applications where it 15 necessary to monitor object s position or size or translucency and to provideaa continuously variable control signal for another analogue device like a motor speed control 2 1 4 Evaluating a sensor Since there are even more types of sensors than physical variables to measure the user must make a selection based on one or more of these criteria which are very important for choosing relevant sensor for any typical application Sensitivity This is a measure of how much the sensor output changes in response to a given change in the quantity being measured Resolution Minimum detectable measurand When deployed any sensor will respond not only to the measurand but also to vari tions in other environmental variables and to inevitable electrical noise For example the output of a pressure sensor may also depend on temperature to some degree The minimum detectable measurand is the lowest measurand level that can be detected in the presence of all other env
50. ly completed this project CHAPTER 8 PROJECT MANAGEMENT 8 1 Overview For the successful completion of the project the project time management is a key issue at the beginning of a project Initially the project time plan had been elaborate in the feasibility study with regards to the time allocated to the different project stages and submission deadlines defined by the department as described in the Major Project Information for Students amp Staff handbook Through out the project this timing schedule is strictly followed This chapter includes the initial timing deadlines and the actual time which author spent on this project As the final time plan 15 slightly different from the initial time plan therefore certain tasks had been readjusted Time Management Time planning is important in ensuring the progress of the project on track to completion good time plan would have a flexibility or allowance of time in completion of every stage of any project that is taken Tasks Performed Initial Time Planned Actual Time Spent Choose Sensors and 8 Weeks 10 Weeks Motors Hardware Circuit Desig 4 Weeks 8 Weeks Software Learning 4 Weeks 4 Weeks nterfacing with 68000 4 Weeks 5 Weeks Troubleshooting and Testing 8 Weeks 8 Weeks Table 8 1 Time table of the important steps of the project At the start of the project initial time plan Gantt chart was drawn up in the feasibility report but that time plan is li
51. n call implemented on microprocessor 68000 and using pointers for direct access to a physical address space Some research was also conducted on the Debugger and Compiler featuresyand various functions of EDS like step over trace options and implementation of bteakpoint in 68000 programs Many of the features of the EDS are studied with the online help system present in it More detail intosthe language software requirements for the project is given in chapter 3 4 Summary This chapter includes the summary of the theoretical research done by the author in the field of hardware and software for his project and the results obtained from this search CHAPTER 4 C LANGUAGE AND 68000 4 1 Motorola 68000 The 68000 microprocessor is manufactured by Motorola which contains a 16 bit wide data bus and an internal address bus of 24 bits Itus capable of accessing a linear address space of 16 Megabytes It is driven by a 10 MHz clock generated by a CMOS oscillator The 68000 has sixteen 32 bit registers split into data and address registers One address register is reserved for the Stack Pointer Any register of either type can be used for any function except direct addressing Only address registers can be used as the source of an address but data registers can provide the offset from an address Externally the address bus does not include the least significant bit 0 which means that odd addresses are not addressable I
52. n time here AS and UDS data enables the 3 8 decoder Here one sensor works at a time which is chosen by the status of Port A switches of the PI T ADC BOARD ps m D0 D DI D10 2 DI D a N 012 LL SCO Ain D13 e D5 Ain4 D14 LL 06 5 DIS D7 Ain6 Ain ZEEER ttt 1 0 Port B Port A PU B T 6 8 A 2 B 74138 3 3 8 DECODER 0 0 0 NOT Figure 5 15 Experimentalsetup of the whole system The status of tlie switches of Port A of the PI T which decided that which input of the ADC is Worked at present is given as follow gt PAO switch active and other switches are in active then only 0 sensor works gt If only switch active and other switches are in active then only Ainl sensor works gt If only PA2 switch active and other switches in active then works gt If only switch active and other switches are in active then works gt If only PA4 switch active and other switches in active then works gt H only PAS switch active and other switches are in active then works gt If only 6 switch active and other switches are in active then works gt If only PA7 switch active and other switches are in active then works 5 8 Summary only only only only only only Ain2 sensor Ain3 sensor Ain4 sensor Ain5 sensor Ain6 sensor Ain7 sensor This chapter contains all the
53. nd proved to function correctly according to their design In doing this project the author learned how to use a microprocessor 68000 from both hardware and software approach When dealing with this project it is found that it could not always simply follow the theoretical ideas due to physical limitations everything seems to be working fine could also go wrong at any time so it must prepare more time for testing and debugging The flexible development platform is designed successfully but it has some drawbacks as well In this platform the sensors output is changed by the physical parameters of the environment and this analogue data is given at the input terminal of the ADC to convert it into digital value Than this data is synchronously transfer at the output port B of the PI T 68230 by using VMA Valid Memory Address and VPA Valid Peripheral Address signals of MC68000 to control the speed of the stepper motor connected at the port B The use of C language programming also increases the reliability and functionality of the program This platform has many real world applications like Temperature Control Air Quality Monitoring Traffic Counting Energy Management etc However even after the understanding of the subjects of Microprocessor and sensors this project has one drawback that only one sensors is active at a time which is controlled only by the status of the switches of the input port A of the PI T68230 But this
54. nstead of AO two data strobes are provided UDS Upper Data Strobe and LDS lower Data Strobe These data strobes are active low signals and indicate whether the upper or lower byte of a data word is being addressed If an entire word is being addressed then both data strobes are asserted 12 UDS and LDS can be used within a systems address decoding At the simplest level UDS and LDS can be connected directly to the chip select or chip enable input of two 8 bit wide data bus memory devices thus the upper and lower bytes of the word are stored in physically separate devices One signal of importance to bus transactions is the read write output WR When this output goes low it indicates that the processor has started a write cycle When the output is high is means that a read cycle is in progress The important feature of 68000 is asynchronous data transfers which differentiate from other processors Handshake signal generated by the device being accessed Indicates that the contents of the data bus is valid This handshaking signal is used as an input to the 68000 to inform it when an external memory device or peripheral has provided or responded to data on the bus This handshaking signal is called Data Transfer Acknowledge DTACK and is active low If DTACK is not asserted CPU generates wait states until DTACK goes low or until an error state is declared When is asserted CPU completes the current access and b
55. ntrol register Port B control register Port A data register Port B data register Port A alternate register Port B alternate register Port C data register Port status register Timer control register Timer interrupt vector register Type R w R w R w R w R w R w R w R w R w R only R only R w R w R w EE E APPENDIX D bech bh em C DW Cor E 0D m CPRH CPRM CPRL CNTRH CNTRM CNTRL TSR Counter pre load register high R w Counter pre load register med R w Counter pre load register low Counter register high Counter register medium Counter register low Timer status register Stepper Motor Board Circuit Diagram INDEXPULSE 1 SEGMENT PULSE TRI BCHASB Index Pulse LED Stret LED RIA IMR TR R w R only R only R only R w Title STEPPER MOTOR TOP BOARD Size B GES BL VERSIO Dus J0 Tun 2008 Bai d De Digests 68h CN L Dom Tom 3 LU vL D unm EI mmm M D pm m 2 D 100 D mp Dm 1 D d D H D gn M D mt D Zelt L t J PAT LEDPAT 1Eppni Lann LED PES AEN 1 SKPI Dm nl 1
56. or is simply dependant on the life of the bearing 6 The motors response to digital input pulses provides open loop control making the motor simpler and less costly to control 7 It is possible to achieve very low speed synchronous rotation with a load that is directly coupled to the shaft 8 A wide range of rotational speed can be realized as the speed is proportional to the frequency of the input pulses Disadvantages 1 Resonances can occur if not properly controlled 2 Not easy to operate at extremely high speeds 245 1 Control of motor Controlling of the stepper motors is done by using pulse controlling The control pulse is positive going pulse with length of 1 to 2 ms which is repeated about 50 60 times a second The details are in the figure 2 5below 5V GND On Period 4 Off Period Figure 2 5 Square Waveform Stepper motors are controlled by sending them a pulse of variable width The parameters for this pulse are that it has a minimum width a maximum width and a repetition rate These values are not standard but there are conventions hat are generally accepted The speed of the motor depends on the duty cycle of the pulse i e Duty cycle On period Off period 2 4 Summary This chapter is for only those readers who are not aware of the basic fundamentals of the sensors and actuators motors It consists of the sensor theory with its types and working Advantages
57. process over 1000 commands pet second The RCX uses an 8 bit Hitachi H8 3297 microcontroller running at 16MHz It has 16K of ROM 512 bytes of SRAM for firmware and 32K of external SRAM for the programs 2 1 3 Projects Aims and Objectives The aims and objectives of this project have been proposed in the early stage of the project work with the elaboration of the feasibility study report The key objectives that need to be considered and accomplished in order to achieve the aim of designing a working platform which satisfies the design brief are listed below gt To learn and understand the function of the Lego Mindstorms robots to develop flexible development platform for interactive robots gt To study and research on different type of sensors used in Robots gt To interface the sensors with the 68000 microprocessor as input with motor which is connected atoutput gt To learn hardware troubleshooting learn self discipline and time management gt Learnand research about the MC68000 microprocessor and the Flight 68000 training systems available within the university in particular how to use and interface to them gt Design and build circuitry to interface to the MC68000 training system and software program suitable for operating the completed hardware gt learn how to communicate and discuss with supervisor and people relevant about the project gt To gain valuable knowledge and Experience in the Microprocessor Sys
58. put More than one motor can be easily used by using the timers of the PI T Program Interface Timer 68230 or by designing the motor controlled circuit which able to control the working of more than one motor simultaneously Ny E 1 http www robotbooks com Leggo Mindstorms htm ione Robotics Invention System 1 5 O 1999 the LEGO Group 3 http research cs tamu edu prism lectures iss iss ID glff 4 http www plazaearth com usr gasperi lego htm basics 5 www dcpmicro conn 6 MC68000 8 16 32 Bit Microprocessors User s Manual MC68000UM Ou Ed Motorola Inc p11 22 7 http www flite co uk micros flt 68k html 8 http balder prohosting com sywu Clang_1 htm 9 http www seattlerobotics org encoder jul97 basics html basicof sensor 10 http Avww crossware com press october01 flt68kts htm 11 httpz www crossware com datasheets flt68kts 12 Clements Alan Microprocessor System Design 68000 hardware software interfacing 3 edition Boston Mass London PWS Publication 1997 13 Mini Projects 2ELE0047 Reference manual LD403 lab provided by Dr David Lee 14 http www acfr usyd edu au teaching 4th year mech47 721 Signals material lecture s sensors 1 Introduction pdf 15 http Avww legomindstorms com internals BIBLIOGRAPHY 1 Walter Triebel A and Singh Avtar The 68000 and 68020 Microprocessors Prentice Hall 1991 2 http dragon herts ac uk labs
59. rief summary of all chapters including in this report Chapter 1 Introduction This chapter describes the project overview its background theory and the report to the reader It contains brief overview aims and objectives of the project with its some applications and how the report is organized Chapter 2 Sensors and Motors This chapter covers the information about the basic theory behind the sensors with their advantages and disadvantages It describes the technologies sensors and motors available to do the project Here are discusses several possible implementation options It also include is a discussion aboutthe advantages disadvantages of technology available and why it was Chosen a certain one to develop the current application Chapter 3 Literature research Summary of the research carried out for the project in its hardware and software field and conclusion drawn from this culminating in the project design specification Chapter 4 Motorola 68000 It contains the brief summary of the MC68000 and FLIGHT 68000 Microprocessor training system board with the reasons for choosing language for programming Chapter 5 Hardware design A detailed description of the design of the different types of the sensors Is given in this chapter It also includes the various circuits using for interfacing of flexible system with MC68000 and details of memory mapping Chapter 6 Software desi
60. rs at the input A microprocessor FLIGHT 68K training board connected with PC via RS232 cable Stepper motors which are controlled according to the physical parameters of the Sensors Designed circuitry to interface all these sensors and actuators with MC68000 and stored in memory by interfacing with microprocessor Analysis of this stored data can be done to control the real Ki lications like speed of the stepper motor is controlled in term of the temperature of wa y using temperature sensor here Some possible cu ication of this flexible system includes Gas Industry Gas Flow Pressure and Telemetry outstations Temperature control River Reservoir and Borehole Water Level Water Quality Parameters Rain Gauging Pump Duty Monitoring Low Power Telemetry Other Applications Intelligent Children Toys Energy Management Traffic Counting Industrial plant Monitoring Pollution and Environmental Studies Offshore Marine Systems Air Quality Monitoring 1 5 Chapter Organisation The report is targeted both at the experienced electronic engineer who is and is not a specialist in the field of sensors and developing flexible platform different applications including MC68000 interfacing The former can start from Chapter 5 directly to understand all the experimental results and electronic parts The latter may study the whole report to learn the theory parts as well electronics parts The following section contains a b
61. s Measurement Sometimes requirements matched to transmitter Characteristics Cannot be detected High range and angle Covert resolution possible Large variety Radiation pattern Constrains Observations Disadvantages Passive Active Target of interest Large power must radiate or modify the requirement field elec gravity Easy to detect Availability not guaranteed not covert no light contrast etc Complex transmitter Typically short range though and receiver logic not always astronomy determined Prone to feature ambiguity Reliability and error of scale e g Angle by transmitter and only receiver only 2 2 Lego Mindstorms and DCP sensors There is a similar project called The Lego Mindstorms Robots from which author take a basic idea for this project Initially author decided to use the sensors of this system in his project as described in the project background The Information on the light sensor touch sensor and distance sensor input values were found on MindStorms RCX Sensor Input Page website Various experiments had conducted to make these sensors appropriate for using in this project but found that the inputs and o tputs of these sensors were taken from the same wire For example in light sensor the input sends a high 8 VDC level for around 1 2ms and disconnects it for around 0 1ms whichis when it reads the sensor as output A brief description of these sensors
62. se 13 5 6 Address Decoding Externally the Motorola 68000 is seen as having a 23 bit address bus as it does not provide address line AO with the consequence that odd addresses can not be accessed Instead the 68000 provides an upper and lower data strobe UDS and LDS which are used to select an upper or lower byte of the memory word addressed by A01 A23 To select one inputof ADC is working at a time full address is chosen Any Microprocessor is said to have Pult address decoding when each addressable location with in a memory component respond s only t a single unique address on the system address bus In other words each physical memory location either by specifying a given device or by specifying a address with in it 3 Full address decoding can be applied to the problem of distinguish two or more memory components or any external device like any one input of the ADC is selected according to the following address decoding table 5 4 A23 A22 21 A20 A19 A18 5 4 2 1 0 DCPTR DC Input Selected address 1 1 0 00 0 0 0 Db00000 Amt 1 1 0 00 0 0 00 0 1 0 D00002 Ainl 1 1 0 00 0 0 150 0 D00004 2 1 1 0 00 0 0 00 4 1 0 D00006 Ain3 1 1 0 00 0 0 0 4 0 D00008 Ain4 1 1 0 00 0 071 01 0 0000 5 1 1 0 00 0 0 0 1 1 0 0 D0000C Ain6 1 1 0 0 0 1 1 1 0 0000 Ain7 Table 5 4 Address Decoding Table The 74138 3 8 decoder is us d for full address decoding shown in figure 5 14 Y0
63. shire which saved the time spent in designing motor controller circuit This stepper motor module is a stepper motor with a disc marked withl2 segments and an index marker on the number one The connections are explained below 13 Inputs Step One step movement is generated for each negative edge of the step sinat Direction Logic 1 for anticlockwise movement Logic 0 for clockwise Half Step Mode Logic 1 for full step and logic 0 for half step mode 4 LED s show the step sequence driving the motor Inhibit Logic 1 to Inhibit driver ic and logic 0 to enable driver ic module Outputs Segment pulse Optical sensors detect each Segment number and produce a logic 1 pulse accordingly Index Pulse Logic 1 output when dise rotates to alignment with number 1 as shown above LED s indicate the pulse outputs 13 POWER t LDF pm M Stepper Motor AR Driver HALF STEP Oy MODE 7 9 L 9 INHIBIT STEPPER MOTOR BOARD Figure 5 11 Stepper Motor Controller Board 13 The circuit diagram of stepper motor board is shown in Appendix D INHIBIT DISABLED ACTIVE STEP CLOCKWISE ANTICLOCKWISE HALF STEP i MODE FULL STEP Figure 5 12 Timing Diagram of Different Modes of Stepper Motor 13 12 1 2 SEGMENT PULSE O P etc INDEX PULSE O P Figure 5 13 Timing Diagram of Segment and Index pul
64. t Studio a user friendly integrated development environment which eliminates the learning curve for using the tools gt Manuals in printed and electronie form gt Secure license server to simplify multi user licensing across a LAN Technical support and free up for 2 months 11 C languages is chosen because of ge many advantages as compared to other Assembler languages and produce efficient code as discussed in chapter 4 Several software design qualities parameters like flexibility efficiency reliability and portability keep in mind before designing this software program 6 2 Software Program The software program represents in this section includes the overall working of the flexible development platform refer Appendix for program coding The program for testing of individual element is given in the chapter 7 Functional test result The Step by step working of whole setup by programming is shown in the flow chart figure 6 1 This program includes the way by which individual sensor is chosen from ADC at a time according to the status of the switches of port A of PI T 68230 and the output is taken from the port B to control the speed of the stepper motor PBDDRPTR 0x800007 PCDDRPTR 0x80004 gt e AS ch 0x80000D char TR 0x 800005 ay RPTR 0x80000F har PBDRPTR 0x800013 char PADRPTR 0x800011 char w7 char PCDRPTR 0x800019 unsigned char ADCPTR 0x00000
65. t proper amplification and also the poor quality micro phon The output varies in only mill volts due to which changes in the speed of the motor are not notable 5y R1 R3 Ac D1 R2 OUPPUT TO THE ADC 5V MICROPHONE OPAMP D1N750 2k Sound Sensor Circuit Fig 5 7 Sound Sensor Circuit Diagram 5 2 Analogue to Digital converter Microprocessors almost always deal with discrete values Processor such as the 8085 deal with 8 bit values An important part of using an Analog Signal is being able to convert it to a Discrete Signal such as a 8 bit digital value This allows the Microprocessor to do things like compute values and perform comparisons Fortunately most modern processors have a resource called an Analog to Digital converter A D converter 9 The function of the A D converter is to convert an Analogue signal into a digital value It does this with a mapping function that assigns discrete values to the entire range of voltages It is typical for the range of an A D converter to be 0 to 5 volts The A D converter willsdivide the range of values by the number of discrete combinations For example the table 5 2 shows the samples of an Analogue Signal that have been converted into digital values 9 Volts Volts Conversion 0 0000 0 0195 0 0391 0 0586 0 0781 These digital values are then expressed as a digital number using binary numbering system consisting only of 0 s and 1 s The resulting d
66. tages of the Sensors 16 2 2 Lego mindstorm and DCP Sensors 17 2 3 Choice of the Sensors 19 2 4 Choice of the Motors 20 CHAPTER 3 LITERATURE RESEARCH 3 1 Literature 23 3 2Hardware Research 23 3 3 Software Research gt 4 E _ 24 3 4 14 24 CHAPTER 4 C AND 68000 4 1 Motorola 68000 25 4 2 FLIGHT 68K 1 28 4 3 Choosing C language for programming 30 4 4 31 CHAPTER 5 HARDWARE DESIGN 5 1 Designing and Testing of Sensors 32 5 1 1 Voltage 1501 lt 33 5 1 2 Switch
67. tance Vs Outputvoltage Output Voltage in Volts 5 10 15 Pot Resistance in Ohms e Output voltage Figure 5 3 Graphical representation of output of Voltage sensor 5 1 3 Switch Sensor One of the most basic of all sensors is a simple switch Switches are used in bumper sensors to detect limits of motion for user input and a whole host of other things Switches come in two types normally open NO and normally close NC Many micro switch designs actually have one common terminal and both a NO terminal and a NC terminal The circuit in figure 5 4 shows how to potentiometer is used as a analogue switch sensor Reference voltage of 2 1 V is given at the inverting terminal of Op Amp by a Zener Diode This voltage across Zener Diode switch the output voltage between 2 1 V and 4 9 V by rotating the knob of potentiometer from minimum to higher position The Op Amp is used in non inverting mode which acts as amplifier only OUTPUT TO THE ADC D1 R2 IE Aces R4 D1N750 2k wae SWITCH SENSOR Fig 5 4 Switch Sensor 5 3 3 Light Sensor A simple LDR application is implemented for designing light sensor When there is NO light falling on the sensor the resistance of LDR becomes infinite When light falls on the LDR the resistance changes according to the intensity of light Example uses for this circuit Dark room Automatic door lock closet
68. tem Design Electronic Sensors Robotics C programming and Project Management areas The main objective of the project is to obtain the best suitable sensors in term of cost and accuracy to design this flexible platform Some experience and new knowledge have been gained during the project research assembling and interfacing the sensor with RCX Besides that it helps to improve technical skills and to solve problems more efficiently Most important of all is the technical apply to the project while assembling the design The following sub objective were achieved To build design and create a new hardware by which any sensor input device interface with 68000 to control the motor or any equipment according to requirement which is connected at output To Implement the program to simulate the sensors input devices and output devices with FLIGHT 68K using programming language To make the system as much as flexible so that any number of inputs and outputs are connected according to the application To write control program using diff rent type of sensors in C Language To test the accuracy of the sensor interfaced with Motorola 68000 via 68230 Parallel Interface Timer on FLIGHT 68K board so that it performs more like a robot 1 4 Project overview To describe the project overview the general block diagram overall system is shown in the figure 1 2 which consist of A platform of different senso
69. the value Of the signal applied to the 2mm connector or from the switches on the board The input source is set with the double switch towards the bottom of the board To use the board connect it to the flight 68k board via the 40 pin IDC connector 13 Power is supplied to the board via one of the two power connectors to the right of the IDC connector The power source must be 5 volts and can be sourced froma 5volt PSU or from daisy chaining a power cable from another board The circuit diagram of I O buffered board is shown in Appendix E Before using the board it must set the ports to the appropriate settings in the program as the board will not work otherwise The Port data direction registers is set to the appropriate values like Port A Data Direction Register needs to be set to input 0x00 and Port B to output Oxff and Port C to OxOf Other registers are to be set depending op he application as shown in the program in Appendix B 2 Before implementing in the project initial testing is done which is Input port PAO PA7 given in Chapter 7 Output port PBO PB7 GE Input port DC A DCH Output port PCO PC3 Figure 5 10 HO Buffered Board 13 5 5 Stepper Motor Controller Board The stepper motor is used at the output and its speed is controlled according to the physical parameter of the environment sensed by sensors The stepper motor controller board is taken from Microprocessor lab of University of Hertford
70. tinue further research on the DCP sensors 5 In figure2 4 function of two extra pins also shown for using same socket for all digital and analogue sensors of DCP series 5 Woltage mferernce o utpit 2 5 volts 2 Supply ground 0 volts 3 Analogue signal input to Z 5 volts 4 Supphbecoutput 5 volts Microserse identification input 0 to 2 5 v 8 Ztart rnarkinpat 0 to 5 volts Digital signal patt to 5 volts Pin Out Socket view Figure 2 4 Function of pins of DCP sensors 2 3 Choice of the sensors After the study of above discussed Light sensot Touch sensor Rotation sensor and Sound sensor it is concluded that these sensors were designed by their companies according to their own software s and design considerations which they recommend for their own systems To use these sensors with this project system become more complex and difficult so author decided to design his own simple sensors which were using as input in the flexible development platform of robot The detailed design and description of these sensors is given in chapter 5 2 5 Choice of the Motors There are mainly two types of motor used in controlling of a robot the servo motor and stepper motor Both types of motor have used in same applications in robot like positioning but they differ in a number of ways Stepper motor can be viewed as electric motor without commentators they are controlled by one step per one pulse If the load of th
71. tity into an electrical output quantity and of processing it in accordance with a gen algorithm to provide an output suitable for interfacing to a process control system such as c mputer Many measuring and sensing devices as well as loudspeakers thermocouples microphones and phonograph pickups may be termed transducers 14 Any data a computer gets that has not been entered by a human user or already been put into digital form in another computer enters the computer from sensor or transducer The function of these sensors is to convert some measured physical quantity pressure temperature fuel tank level flow rate position velocity acceleration chemical concentration etc into a voltage signal that can then be digitized with the usual analogue to digital A D techniques The technologies of sensors and signal conditioning processing the sensor output to make it compatible with the computer are two of the key drivers of progress in computer based instrumentation control and automation sensors convert different type of energy into the electrical energy as shown figure 2 1 Electrical system Electrical energy Modifying unit A D or D A Figure 2 1 Some types of Energy forms converted by Sensors 2 1 1 Sensor Operational Principle Most of the sensors operational principles is the same as the electromagnetic radar laser etc and active acoustic sensing Antenna Coupler Transmitted Ra
72. ttleybit modified not in term of time scale but only drawing for easy comparison with the final time plan Gantt chart as shown in Figure and Figure comparison of the original time plan and the actual time plan clearly shows that the testing of the different sensors took a tte longer than was originally estimated This is due to the more time devoted to do exp riment on DCP sound sensor and three sensors of Lego Mindstorms for using in this project Fourtweeks were spent on doing research on finding function of different pins of sound sensor and time also spent on contacting DCP commotion group manufacturer But no important information was found which helped in this project So author decided to design his own sensors to develop a flexible platform The technical help for design were answered swiftly but were not always helpful with regards to the questions asked about this project This explains the extension in time while researching stopping The period of time in which the tests for sensor were completed was delayed as a result of the extension in the research to find the sensor in which output and input were taken from different wires unlike sound touch and distance sensor of Lego Mindstorms Due to this the development of the sensor started later than anticipated This task ran into frequent difficulties as mentioned earlier in chapter 10 Due to these factors the sensor electronics did not reach its full potential but this
73. ucted on the internet to see if any similar products were already in production like Lego Mindstorm robot and DCP sensors or any other manufacturer The only results found were for Lego Mindstorm systems of which no design details were given as might be expected for commercial reasons No information was found for the internal circuitry of the different sensors which were used by current manufacturer because all these sensors were design according to their own software s A deep research was carried out on Logit Sound sensors provided by DCP manufacturers Light sensor Distance sensor and Touch sensor used in Lego Mindstorm robot A research was also conducted for studying advantages and disadvantages of using memory mapping and program interface timer for interfacing of designed sensors system with 68000 Different analogue to digital conversion ADC and digital to analogue conversion DAC techniques were also studied Detailed hardware design and implementation of information gained from the literature search starts in chapter 3 3 Software research For the programming of MT68000 research was carried out into the relation between language and microprocessor 68000 Deep study of C language is done for software programming Research was conducted into specific areas of language such as various library functions including in microprocessor features of the Embedded Development Studio EDS C functio
74. will allow further work to be carried out The design for this project was kept as simple as possible a consequence of this the construction time was less than had been estimated The period of time left for debugging and troubleshooting was also extended but in general jt can be seen that this project progressed steadily and kept to plan Figure 8 1 shows the initial Gantt Blue Color chart created at the start of the project Efforts were made to adhere to the initial Gantt chart throughout the project but where this became impossible the Gantt chart was updated The final Gantt chart Red Color at the end of the project following all updates is shownuin figure which shows the actual time spent on this project Contents 23412 4 12341234012 341234412 4 12 34 2 Determine Aims and Objectives B Background Study m omponents eg DEET BR emm pm Specifications 68000 sm Cette Design General interface analog circuit design B Modify above circuit ith Multiplexer and ADC B yInterfacing with 68000 application board O Programming work Develop the basic idea or programming in C lte nterface input amp output device programming to make system more flexible Gantt chart continues on next page continue 3 Troubleshooting T esting 8 Debugging 4 Final Testing and Project Demo 5 Report Writing Ss 6 Submission of Final Project Report
75. y to study my Master s degree in U K andysupports me all the moment This project and report would not have been completed without the encouragement and love which I received from my family CONTENTS I Certificate Abstract III Acknowledgements IV Contents V Listof Figures and Tables CHAPTER 1 INTRODUCTION 1 1 Preview 2 1 1 2Project Back ground 1 1 3 Project Aims And Objectives 3 1 4Project Overview 88 4 1 5 Chapter Organisation 2 6 1 5 Summaty 8 CHAPTER 2 SENSORS AND MOTORS 2 1 lt 9 2 1 1 Sensor Operation Principle 10 2 1 2 Types Of Sensors 11 2 1 3 Sensors Output Values 12 2 1 4 Evaluating a Sensor 12 2 1 5 Advantages and Disadvan

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