Microcontrollers In Wireless Sensor Networks

Microcontrollers In Wireless Sensor Networks ABSTRACT: Now a days wireless sensor networks have been gaining interact with physical in world. Whereas these can be used in different applications in medical, military, roadside, industrial etc .In the wireless sensor network reducing power is the main importance. In wireless sensor network, which are using battery operated sensors need low-power component devices to increase the life time of the sensors and also gives rise for wireless sensor networks which prolongs the life time for sensor nodes. In this we explore about the three different microcontrollers in wireless sensor and also we discussed about the characteristics of the typical wireless sensor network application. They are Microchip, AVR and MSP430 series. By comparing this we conclude which is best for the wireless sensor network. Now a days these microcontrollers are commercially using in sensor nodes. 1. INTRODUCTION: A sensor node is a node which is able for performing some processing, collecting sensor informations and communicating with other connected nodes in a sensor network and it is also called as mode. These sensor nodes usually have very small computers and storage capability compared to desktop computers. This can be attributed to their use of very low power microcontrollers. Microcontrollers perform the main task in the sensor nodes i.e. processing the data and controlling the functions of the other components. These are some of the controllers using as Digital Signal Processors, Field Programmable Gate Array and applications. So microcontrollers are more suitable for sensor nodes. The best choice for embedded systems is to use microcontrollers because of the services providing by them, like it can connect to other devices more flexible and the power consumption is less. Digital Signal Processing is commandeering for broadband wireless communication, but according to wireless sensor networks the communication should be simple and easy to process. Field Programmable Gate Array are not used in wireless sensor network because it should required more time and energy for the reprogrammabling and reconfiguring to their usage. Application-specific Integrated circuits are performing as hardware where as microcontrollers are providing as softwares.So a wireless sensor network mostly uses microcontrollers. In this wireless sensor network we uses so many microcontrollers with different companies they are Microchip, Atmel etc. There are three different typical micro controllers which are used in wireless sensor network applications .they are Microchips, AVR series MSP430 series. 2. TYPICAL MICROCONTROLLERS USED IN WSN APPLICATIONS: 2.1. Microchips: PIC microcontrollers are made by microchip technologies limited. These are mainly used in industrial development due to their low cost and it has serial programming capability. The features for microchip are explained below. 2.1.1. Interrupt structure: In the PIC microcontroller interrupt structure is very simple but powerful, we can set the priority levels to the interrupts i.e., high or low and also these are useful for real time interrupts. 2.1.2. Instruction set: For the lower end PICs it varies about 35 instructions and for higher end PICs it varies about 80 instructions.pic micro controllers called as 8bit micro controllers because we have different PIC series for example PIC12 series size varies from 12bit and 30bits in the PIC30.in this single cycle execution with single delay cycle. 2.1.3. Memory architecture: PIC microcontrollers follow Harvard architecture nothing but separate code and data space. This microcontroller have number of register files which works as general purpose ram some of special purpose control registers for on chip researches. In this memory is divided in to banks. 2.1.4. Input and output features: For every microcontroller we have I/O ports, which are used for transceiver and analog to digital conversion interfacing. But for some of the PIC series microcontrollers have on-chip ADC, due to this we used direct for analogy data from the transducer.PIC series also having the hardware which can carry SPI out. 2.1.5. Applicability of low power techniques: These microcontrollers are able to operate over a wide frequency and voltage range which makes frequency scaling possible. Some of PIC series dont support frequency scaling but due to the external hardware they can support they are PIC12 and PIC16.but some PIC series supports the frequency scaling because of having the internal RC oscillator which can be used as clock. Due to this clock switching it takes time for result. 2.1.6. Low power sleep mode: By comparing the microcontrollers the PIC series microcontrollers are simplistic. Due to this lower end PICs doesnt have sleep modes. But for PIC16 microcontrollers it has only one sleep mode which was placed on processor core, for PIC18 series have two sleep modes if the peripherals are running then the core is shut-off and it is vice versa for second sleep mode. 2.1.7. Pipelining: PIC instruction takes one machine to execute i.e. 4 clock cycles. For execution it takes two phases fetch and execute. This is a two stage pipeline. 2.1.8. Shortcoming: PIC microcontrollers have a small set of instruction set but these are best comparing to RISC devices. But PIC architecture doesnt have more advantages compared to RISC.They are, it doesnt have load-store architecture, due to this the memory direction refers in arithmetic and logical instructions. By comparing to RISC processor, this PIC has only a single register but for RISC typically includes 16. 2.2. AVR series: The AVR series microcontroller is also fallows the Harvard architecture.ATMega128L microcontroller is widely used in sensor nodes. The features for AVR are explained below. 2.2.1. Interrupt structure: AVR microcontroller is a powerful interrupt structure for AVR interrupt execution is enabled for four clock cycle minimum. Then the program is executed. 2.2.2. Instruction set: The AVR ISA is more suitable than 8-bit microcontroller. The ATMEGA128 offer 133 powerful instructions. Each instruction takes one or two 16bit words. In this instruction set arithmetic operations work ob register R0-R32, but not directly on RAM. 2.2.3. Memory architecture: The Harvard architecture type AVR is based with programs and is stores data separately for performing and parallelism. Flash, EEPROM, SRAM are single integrated chip. The register file, input out registers, and SRAM are data address space. 2.2.4. I/O features: General purpose I/O ports are bi-directional. These AVRs has a built in ADC and Analog comparators. In AVR on Chip Debugging (OCD) support through JTAG.The flexible communication in AVR is serial peripheral interface and a two-wire serial interface and these are analog comparators. 2.2.5. Applicability of low power techniques: In this the low voltage is operating down to 1.8v.in this voltage is available and also frequency scaling also provided. 2.2.6. Low power sleeps modes: It also fix power sleep modes they are Idle, ADC noise reduction, power-save, power-down, stand by and extended stand by. 2.2.7. Pipelining: In this microcontroller each instruction occupies one or two cycles and it also consists of fetch and the execute cycle. It also has single level pipeline design. 2.3. MSP430: These types of microcontrollers are by Texas instruments. It is one of the lowest power consuming processor in the market at present. It is ideal for wireless applications and embedded systems. The features for MSP430 are explained below. 2.3.1. Interrupt structure: In the MSP430 microcontroller interrupt structure provides two timers and a watchdog timer. It is also a power interrupt structure. In this interrupts have fixed priority by ordering. 2.3.2. Instruction set: The MSP430 is a 16-bit RISC processor and it has common RISC features in ISA. in this controller it has 27 core instructions and 7 addressing modes are present. These are having three core instructions format they are operand, operands or a jamp.In this both dedicated stack and stack are available. 2.3.3. Memory architecture: These microcontrollers are also uses same space and data as per above discussed controllers. In this the entire ROM and RAM a single 16-bit pointer is used. This processor contains 16-bit register.R0 is a program counter,R1 is a stack pointer,R2 is a status register and R3 is a special register i.e. nothing but a constant generation.R4 to R15 is for general use. 2.3.4. I/O features: The host of I/O features are built in msp430.for interfacing devices like radio and transducers it has 10 I/O ports. UART and SPL support are available on the type of models. 2.3.5. Applicability of low power technique: For low power applications the msp430 is neutral. With the help of its supply voltage supervisor it can sample input voltage and at each time it can set below a software programmable threshold. 2.3.6. Low powers sleep modes: Six different power modes are available for msp430. Wakeup time is 6micro sec with the use of digital oscillator. 2.3.7. Pipelining: It is not a pipelining architecture. There is no pipeline because they have different number of cycles in instruction but the positive is the most instructions run in one cycle which doesnt make the processor too down. The maximum clock frequency is slower when compared to other because of it lack of pipeline and division of instruction cycle. 2.4. Comparison between PIC and AVR microcontrollers: In PIC microcontroller the memory architecture requires bank register to access 256 bytes of memory but for AVR no need of bank to access the data memory.PIC has only one general purpose register but AVR has 32 general purpose registers.PIC doesnt have SRAM where as AVR has SRAM that the stack is contained within SRAM in order to build the hardware stack.PIC18F and AT Mega having hardware multipliers where as AT Tiny and PIC16F dont having hardware multipliers.PIC is having high clock speed but it is divided by four to give the actual instruction rate. By comparing ATMega128L and MSP430 have rich instruction set and also it has a wide range of arithmetic instructions sets, many addressing modes. But in PIC18 and 8051 microcontrollers are limited. But PIC16 has add with carry instructions. The MSP430 has 40 digital pins, ATMega128L has 53 pins, PIC18 has 36, and PIC16 33 and 8051 has 37. 3. CONCLUSION: These microcontrollers are the central parts of any kind of sensors nodes. We have different types of microcontrollers in the present market which have almost same feature with the life of battery we can know the lifetime of the node. With the kind of memory access, instructions we known, how the execution of code is performed. The processing task can be done with more complex instructions, allowing more sleeping time to the system. It has the ability for self programming which is a useful feature. The efficient code will be generated with a well optimised version. But it doesnt deal well with the accumulator. Finally by comparing these three different microcontrollers MSP family series microcontrollers are better than the others. Because, its work better than the older microcontrollers and it completely dominates or rectifies the problem and works.

Comparing Sin in Fire From Heaven, Much Ado About Nothing, and The Flea :: comparison compare contrast essays

Sin in Fire From Heaven, Much Ado About Nothing, and The Flea In Fire from Heaven, Much Ado About Nothing, and The Flea, the authors take a stance on men and women committing sinful acts and using it as a main position in their work. They write from a very religious perspective which is probably due to the time period in which their work was written. They develop this idea in very different perspectives to get their point across. They express this position vividly throughout their work. David Underdown didn't live in this time period, but his work was a work of history and his ideas coincided with those of the Puritans. He uses these ideas to take a position on the Puritan's side and to better explain the good they were trying to achieve. The Puritans of Dorchester as we have learned about our reading, were a very religious group who wanted to create the perfect society. Their mission in Dorchester was to make extinct all the sinful acts of the townspeople. The struggle they started soon ended in failure. They were a definite influence upon his work. His views of sexual misconduct between married men and women being worse than that between unmarried people probably come from his growing up in a more modern world. The Puritans probably did distinguish some, but it wasn't very prominent or apparent. His makes this point clear in the passage, "Misbehavior among married people was especially serious, as it was likely to disrupt existing families, which were of course regarded as the essential foundations of any ordered, virtuous society(p.66)." The Puritan influence is very prominent in excerpt from the previous quote, "families,... the essential foundations of any ordered, virtuous society(p.66)." Underdown also makes a reference to the others towns in the area and how the Puritan presence made a difference, "It is unlikely that Dorchester people were any more, or any less, loose in their sexual habits than their neighbors in other place. But stories of their misdeeds even in the years of the puritan ascendancy are abundant(p.66)." With this passage the author shows how the presence of the Puritans changed the total view of the town and its people. Underdown used the sinful acts between men and women to draw out Comparing Sin in Fire From Heaven, Much Ado About Nothing, and The Flea :: comparison compare contrast essays Sin in Fire From Heaven, Much Ado About Nothing, and The Flea In Fire from Heaven, Much Ado About Nothing, and The Flea, the authors take a stance on men and women committing sinful acts and using it as a main position in their work. They write from a very religious perspective which is probably due to the time period in which their work was written. They develop this idea in very different perspectives to get their point across. They express this position vividly throughout their work. David Underdown didn't live in this time period, but his work was a work of history and his ideas coincided with those of the Puritans. He uses these ideas to take a position on the Puritan's side and to better explain the good they were trying to achieve. The Puritans of Dorchester as we have learned about our reading, were a very religious group who wanted to create the perfect society. Their mission in Dorchester was to make extinct all the sinful acts of the townspeople. The struggle they started soon ended in failure. They were a definite influence upon his work. His views of sexual misconduct between married men and women being worse than that between unmarried people probably come from his growing up in a more modern world. The Puritans probably did distinguish some, but it wasn't very prominent or apparent. His makes this point clear in the passage, "Misbehavior among married people was especially serious, as it was likely to disrupt existing families, which were of course regarded as the essential foundations of any ordered, virtuous society(p.66)." The Puritan influence is very prominent in excerpt from the previous quote, "families,... the essential foundations of any ordered, virtuous society(p.66)." Underdown also makes a reference to the others towns in the area and how the Puritan presence made a difference, "It is unlikely that Dorchester people were any more, or any less, loose in their sexual habits than their neighbors in other place. But stories of their misdeeds even in the years of the puritan ascendancy are abundant(p.66)." With this passage the author shows how the presence of the Puritans changed the total view of the town and its people. Underdown used the sinful acts between men and women to draw out

Transportations Effect on Social and Economic Change in America Between 1820 and 1860

In what ways did developments in transportation bring about economic and social change in the United States in the period 1820 to 1860?Between the 1820s and the 1860s, advances were being made in leaps and bounds, especially in transportation. From the invention of the cotton gin to interchangeable parts, mechanical advancements began to take effect. However, Americans were still walking on unprepared ground and taking longer to reach from point A to point B. Because of this boom in technology, in order to get material from one place to another, transportation innovations needed to take place. Thus sprang canals and steamboats to navigate these canals in a timely manner.Roads were created to make travel on horseback or horse-drawn chariots much faster and smoother. Railroads and the train were used to make interstate travel fast and efficient. However, these innovations in transportation did not just affect how fast an American got from point A to point B. Transportation developments also affected our country in other ways, such as economically and socially.Innovations in transportation such as canals, railroads and roads, had a major effect on United States. The Philadelphia Lancaster Turnpike was the first important road in America. It connected Philadelphia with rich farm lands in Lancaster. Because of the success of the turnpike, other states were more inclined to do the same. Cumberland Road was built which connected Maryland to Illinois. Canals impacted the US as well. In 1825 the Eerie Canal was opened starting in Albany by the Hudson River to Buffalo (Great Lakes). This enthused economic growth.Tolls were placed along the length of these turnpikes and canals in order to repay construction costs. Railroads changed small rural towns to commercial metropolises. Railroads began developing in the 1830s and it connected water routes when it was first created. By the 1860s there was approximately 30,000 miles of track. Capital to finance railroads came from pr ivate investors, abroad, and local governments. Fed government gave public land grants to railroads. These transportation developments have great economic and social change in the United States.When it comes to the economic aspect of the country due to the innovations in transportation, we really see a tremendous amount of growth in the North.  Due to many Englishmen who brought their blueprints and ideas along with themselves and who settled mostly in the North, manufacturing and industry began to spread throughout the Union. North and South began to cooperate more in industry, the South providing â€Å"King Cotton† and the North turning that cotton into textiles, the first industry in America.Because westward expansion was now beginning, the problem on conveyance of goods from East to West and vice versa was presented. Therefore, canals, railroads and roads were necessary, the most effective of the three being canals; railroads were used carriage of large amounts of goods , which is still the case today. The ability to get goods from one location to another in a matter of days rather than weeks increased supply and capital.There were also social changes that took place due to transportation. Exploration was easier and the grip of the government was more extensive. Also, because of the economic changes, changes in the social ladder also took place. In the North, the wealthy upper class owned the factories while the lower class worked â€Å"on the floor†. Because of this, the middle class began to shrink until there was a very few amount of Americans that could claim to be middle class. In the South, the same could be true, in a different sense though. Rather than the wealthy owning factories, they owned land, where they grew their precious cotton. The lower class either worked as servants or in the fields, however, the latter was uncommon due to slavery.Due to the advances in transportation, these changes took place. Whether they were for good or bad is up to us to decide. In my opinion, the economic changes were beneficial to America as a whole. Goods were transported quickly and effectively which increased the total revenue for the nation as a whole and more money means funding for other projects that will eventually benefit the country even more. However, the social changes really affected the country in a negative way. Because of the division of classes, people were treated inferior to others and from there sprang grudges and disputes. Slaves were treated as animals and this lead to the Civil War. Sadly, many of those feelings have continued down to this day. Nevertheless, between 1820 and 1860 transportation shifted the infrastructure and economy of the  USA.

Sociology