The Invention of Microcontrollers - Lab Report Example

Microcontrollers Table of Contents List of Tables 3 4 2.Introduction 5 3.What is a Micro Controller? 6 4.Advantages of Micro Controllers 8 5.Common Types of Micro Controllers 10 5.1.8051 10 5.2.PIC (Peripheral Interface Controller) 11 5.3.AVR Microcontroller 12 5.4.ARM microcontroller 12 6.An Example of the Use of Microcontroller Timer 12 7.Application of Microcontrollers 13 7.1.Vehicles 13 7.2.Spacecraft 13 7.3.Urban Crisis management 14 8.Conclusion 14 8.1.Summary 14 8.2.Future of Microcontrollers 15 Works Cited 16 List of Figures Figure 1: Simple computer architecture 5 Figure 1 2 Figure 2: Simple computer architecture 5 Figure 3: Microcontroller Unit Structure 6 Figure 4: How the Microcontroller CPU works 7 Figure 5: Main features and components of 89S52 architecture 9 Figure 6: Using timer to generate Delay in Microcontrollers 11 List of Tables Table 1: Execution of a simple addition of 4+5 8 Table 2: summarized qualities of microprocessor memory 9 Table 3: The main Features of 8051 microcontroller family 11 1. Abstract The invention of microcontrollers brought with it numerous advantages, applications, and uses previously not possible. Compared to computers, microprocessors enabled the integration of numerous computer components on a single chip retaining functions like I/O, memory, and on-chip processing. Additionally, microprocessors are easy to use, flexible, and easy design and simulation. This paper examines microcontrollers in terms of what they are, their advantages and applications. Additionally, the paper examines the main types of microcontrollers and their main differences. Finally, the paper explores the future of microcontrollers especially on the increasing urge amongst embedded developers to enhance its performance and reduce power consumption. Compared to computers and microprocessors, microcontrollers are a suitable and cost effective alternative that is effective for electronics and other electromechanical applications. 2. Introduction Prior to the invention of microcontrollers, the operation of large electromechanical systems was through huge machines such as automobile engines and furnaces. These machines were responsible for performance and efficiency optimization. The first microprocessor was developed in 1970s by Integrated Electronics (Intel) for a Japanese client company, Busicon. However, when this company declined to purchase the chipset, Intel introduced the chipset into the market as a general purpose micro-processing system 4004. The market reception was a success prompting the second generation microprocessor 8008 in 1974. Later Motorola joined and a wider range of microcontrollers distributed to the market. Today is virtually impossible to work with electronics without microcontrollers. Simple electronics with microcontrollers are ovens, clock radios, toasters, lawn watering, and refrigerators. For sophisticated uses, microcontrollers are found in spacecraft, robots, life supporting machines, and ocean vessels. Although microcontrollers’ functions are similar to those of computers, they are specialized microcomputers and not computers. The basic computer architecture comprises of control logic, registers, instruction register, instruction memory, Arithmetic Logic Unit, Input/output and accumulator as illustrated in figure 1 below. Figure 1: Simple computer architecture Conversely, microcontrollers simply comprise of processor, peripherals, and memory. Additionally, microprocessors are mostly reduced instruction set computers originally programmed using assembly language that presented difficulties and paved way for high level languages like Basic, FORTRAN, Java, and C/C+. This paper discusses microcontrollers in terms of definition, advantages, types, and applications. 3. What is a Micro Controller? The simplest definition of a microcontroller is a small device that controls gadgets, and machines among other things. This device takes the form of an integrated circuit that constitutes a memory and a central processing unit (CPU) just like a computer, but with no input components like a mouse or keyboard (Ibrahim vii) (see figure 2 below). The CPU in the microcontroller is compressed to a very diminutive size through microelectronic fabrication technologies. For the input and output components, a microcontroller chip constitutes low-level hardware like Liquid Electronic Displays (LED) and switches. Consequently, microcontrollers are not intended for human interactive applications, but for control. Today, microcontrollers variations include those programmed for a distinct purpose or the PROM variant (Programmable Read Only Memory), and the reprogrammable or EEPROM (Electronically Erasable Programmable ROM) variant that can be employed for different applications over and over again. The powerful nature of microcontroller comes from the combination of several tested and superior-quality components such as memory, Analog/Digital converters, I/O lines, and timers among others. The components are then placed in a package that uses simple software to control it. Low-level programming languages used to program microcontrollers include Assembly, C, and Basic in which simple instructions are written in the order of execution. Microcontroller’s mode of communication can be parallel or serial depending on the distance between devices. For closely situated devices, parallel communication occurs but for longer distances, parallel communication is the best solution. Figure 2: Microcontroller Unit Structure The operation of a microcontroller operates commences with loading the completed program into the microcontroller by turning off the power supply. Upon turning on the power supply, control logic disables other circuits but enables the quartz crystal. Power supply remains until maximum voltage where the oscillator frequency stabilizes, special functions registers take the bits indicating the circuit states, and all pins are configured as inputs. Then, the program counter is set to zero and increments after instructions from a given address are sent to the decoder. The new PC value is the memory address for the next instruction for CPU execution. After decoding, the arithmetic and logic unit performs all logic calculations while the CPU internal registers stores the results. The figure below shows how the CPU works while the table represents simple microcontroller execution of a simple addition: 4+5. Figure 3: How the Microcontroller CPU works Address Instruction (a binary code value identifying the action to take) 0000 Read the value at memory address 0100, store in Register 1 0100 Read the value in memory address 0101, store in Register 2 0200 Add the value in Register 2 to the value in register 1 and save the result in register 1 Address Data 0100 4 0101 5 Table 1: Execution of a simple addition of 4+5 4. Advantages of Micro Controllers Compared to microprocessors, microcontrollers have numerous benefits including high integration, cost, design and simulation, flexibility, and easy to use (Ibrahim 5). High integration causes the microcontroller to act as a microcomputer without any moving part such as relays that are susceptible to damage resulting from dust, rust, insects, and dirt among others. The small integrated circuit constitutes all peripherals on one board resulting in a device that operates at higher speeds to execute instructions, unlike general purpose microprocessors. Compared to electromechanical predecessors, microcontrollers are cost effective especially if they can be reprogrammed where the designed application fails to work effectively or where its application changes. Summerville (9) highlights that with Flash, EEPROM, and EPROM, any changes can be implemented straight forward on the used control law (summarized in Table 2). Additionally, including numerous components on one IC, component, and board area result in significant savings given that much lower specifications are required unlike low-power general purpose microprocessors. Additionally, microcontrollers require less electrical energy compared to using individual components separately, thus making them energy efficient since only 5V supply is required. Table 2: summarized qualities of microprocessor memory Today, the design and simulation of microcontrollers make it possible to guarantee precision of coding and system performance. Additionally, typical microcontroller applications involve tasks that are too minute and repetitive such that humans can reproduce quick and consistent motions, while increasing productivity. Unlike in the past where assembly language was used for programming, C compilers are accessible that is used on most microcontrollers. 5. Common Types of Micro Controllers The main types of microcontrollers are classified according to bits, architecture, memory, and instruction sets. The major types of microcontrollers include 8051, PIC, ARM, and AVR. 5.1. 8051 This is an 8-bit microcontroller first developed by Intel Corporation in 1981. The microcontroller is available in dual line package present in 40 pin. 8051’s ROM is 4kb, RAM space of 128 bytes, and where necessary an external interfaced memory of 64kb. The microcontroller also has four programmable and parallel 8 bits ports. The available on-chip crystal oscillator has a frequency of 12MHz. The microcontroller also has a 2 pin serial input/output port, two 16-bit timers, a counter, and six interrupt sources (Summerville 9). The timers are 16 bits and function internally while the counter functions externally. The five interrupt sources are Time interrupt 1 and 0, External interrupt 1 and 0, and serial port interrupt. To program this microcontroller, the two forms are SFRs or Special Purpose Registers, and GPRs or General Purpose Registers. The simple architecture for AT89S52 from 8051 microcontroller family is shown below. Figure 4: Main features and components of 89S52 architecture Table 3: The main Features of 8051 microcontroller family 5.2. PIC (Peripheral Interface Controller) PIC manufacturer is Micro-Chip Technology for use in 8-bit microcontrollers. Today, PIC’s popularity lies in its availability, large user base, capacity for serial programming and low cost. The main categories of 8-bit PIC microcontrollers’ architecture are Baseline, Midrange, and high performance architectures. The baseline architecture belongs to the PIC10F family; midrange architecture belongs to PIC12; and PIC16 families, while high performance architecture belongs to PIC18 families. 5.3. AVR Microcontroller AVR or Advanced Virtual RISC is developed by Atmel after customizing Havard architecture 8-bit RISC solitary chip and was the first to include on-chip flash memory that is non-volatile and programmable. The incorporation of SRAM, EEPROM, and Flash on one chip eliminates the need for an external memory in maximum devices. 5.4. ARM microcontroller ARM is genuine RISC design developed by Acorn Computers Ltd. The design lacks on-board flash memory and has great power saving abilities that make it the preferred design for mobile electronics’ processing units. 6. An Example of the Use of Microcontroller Timer In microcontrollers, a timer is recognized as a register that increments its value. Upon getting to register OVERFLOW, a timer is said to have counted maximum value or 255 for 8 bits. Then, the timer gets back to zero where it can issue an interrupt that must be handled by an Interrupt Service Routine (ISR). The available timers in Atmega 16 are TIMER2, TIMER1, and TIMER0. Each microcontroller program must monitor the timer to identify time elapsed during its operation. Through the creation of precise delays, and time generation, the timer counts an event and increments by one whenever similar action takes place. Figure5: Using timer to generate Delay in Microcontrollers 7. Application of Microcontrollers The application of microcontrollers is widespread in embedded devices. Most embedded devices are managed automatically such as appliances including power tools, control systems, automobiles engine control, and office appliances, toys, and others. Microcontroller preference in such devices makes it capable of inexpensively gaining control of numerous operations digitally. Daily uses of microcontrollers discussed in details here are vehicles, spacecraft, and urban crisis management. 7.1. Vehicles In vehicles, microcontrollers are used for vehicle monitoring and security. According to Supriya, Bombale and Patil (56-57), microcontrollers are used for critical remote location application through Global Positioning System (GPS) technology, and real time vehicle position data provision. This active vehicle tracking system constitutes hardware on the automobile, while a tracker server receives vehicle location information through direct TCP/IP through GPRS or GSM modem on a GSM network. The tracking server then stores the receive vehicle information in a database. In the tracking server, the reciption and storage of vehicle parameters occurs in the microcontroller for use in monitoring and control functions. Besides vehicle location, microcontrollers are used for automobile theft control using wireless technology while enabling owners to get involved passively (Dhotre, Chandurkar and Jadhav 101). 7.2. Spacecraft From Universidad de Cantabria (29), the application of microcontrollers in space craft is favorable as a way of cost reduction since it involves the incorporation of numerous peripherals on a one chip thereby, reducing parts counts. This integration results in the reduction of power consumption, volume and mass while increasing reliability. Consequently, the microcontroller is crucial in on-board spacecraft control, particularly data handling for its peripheral-based functions, and data exchange formats and numbers (Universidad de Cantabria 31). The resulting benefits are flexibility in terms of I/O configurable ports, simplicity given reduction in parts count, and advanced system performance. 7.3. Urban Crisis management Rao, Prabu and Lodiwale (35) define increased vehicle population and flood water in urban areas as urban crisis since it puts intense strain in urban roads or traffic congestion. Microcontrollers used in transit systems control to detect the nature of traffic and levels of flooding and provide precise real time numerical data and commence a response in cases of emergency. 8. Conclusion 8.1. Summary Since inception, microcontrollers have found numerous applications, both in simple appliances and sophisticated applications. Unlike computers, microcontrollers have all components integrated on one chip resulting in advantages such as size reduction, lower cost, easier design and simulation, low energy consumption, and ease of use. The major types of microcontrollers are 8051, PIC, AVR, and ARM, all of which vary in terms of number of bits, instruction sets, memory, and architecture. In any microcontroller, a timer is crucial in generating delay to allow event counting and timer increments for similar events. Major applications of microcontrollers are vehicle monitoring and security system, advanced system performance for on-board spacecraft control, and urban vehicle traffic and flood crisis management. 8.2. Future of Microcontrollers The future of microcontrollers is bright with embedded developers pushing for migration from 8-bit architectures to 32-bit architectures, especially due to the increasing need for complex embedded products with superior performance and reduced power consumption. Works Cited Dhotre, Amol, Abhishek Chandurkar and S Jadhav. "Design of a GSM Cell – Phone based Vehicle Monitoring & Theft Security System." International Journal of Electrical and Electronics Engineering (IJEEE) 1.3 (2012): 101-105. Print. Ibrahim, Dogan. Microcontroller projects in C for the 8051. Oxford, : Newnes, 2000. Rao, Samruddhi, et al. "Sensor and Microcontroller based Urban Crisis Management." International Journal of Computer Applications 78.12 (2013): 35-39. Print. Summerville, Douglas. Embedded systems interfacing for engineers using the Freescale HCS08 microcontroller. I, Assembly language programming. California: Morgan and Claypool Publishers, 2009. Print. Supriya, Sawant, Dr Bombale and T Patil. "An Intelligent Vehicle Control and Monitoring Using Arm." International Journal of Engineering and Innovative Technology (IJEIT) 2.4 (2012): 56-59. Print. Universidad de Cantabria. VHDL users forum in Europe : SIG-VHDL Spring97 Working Conference : Toledo, Spain, april, 1997 : proceedings : system modeling and code reusability. Cantabria: University of Cantabria, 1997. Print. Read More