23-08-2014, 03:36 PM
Embedded System on Seminar Report
[attachment=66938]
INTRODUCTION
An Embedded System is a combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to perform a specific function.
A good example is the microwave oven. This is in direct contrast to the personal computer in the family room. It too is comprised of computer hardware and software and mechanical components (disk drives, for example). For a well designed embedded system, the existence of the processor and software could be completely unnoticed by the user of the device. Such is the case for a microwave oven or alarm clock. In some cases, it would even be possible to build an equivalent device that does not contain the processor and software. This could be done by replacing the combination with a custom integrated circuit that performs the same functions in hardware. A lot of flexibility is lost when a design is hard-cooled in this way. It is much easier, and cheaper, to change a few lines of software than to redesign a piece of custom hardware.
In the year 1971, Intel introduced the world’s first microprocessor. This chip, the 4004, was designed for use in a line of business calculators. The microcontroller was an overnight success, and its use increased steadily over the next decade. The embedded system market is one of the highest growth areas as these systems are used in very market segment- consumer electronics, office automation, industrial automation, biomedical engineering, wireless communication, data communication, telecommunications, transportation, military and so on.
Wireless technologies
Advances in mobile communications are paving way for many interesting applications using embedded systems. The mobile phone is one of the marvels of the last decade of the 20th century. It is a very powerful embedded system that provides voice communication while we are on the move. The Personal Digital Assistants and the palmtops can now be used to access multimedia services over the Internet. Mobile communication infrastructure such as base station controllers, mobile switching centres are also powerful embedded systems
Security
Security of persons and information has always been a major issue. We need to protect our homes and offices; and also the information we transmit and store. Developing embedded systems for security applications is one of the most lucrative businesses nowadays. Security devices at homes, offices, airports etc. for authentication and verification are embedded systems. Encryption devices are nearly 99 per cent of the processors that are manufactured end up in~ embedded systems. Embedded systems find applications in every industrial segment- consumer electronics, transportation, avionics, biomedical engineering, manufacturing, process control and industrial automation, data communication, telecommunication, defence, security etc. Used to encrypt the data/voice being transmitted on communication links such as telephone lines. Biometric systems using fingerprint and face recognition are now being extensively used for user authentication in banking applications as well as for access control in high security buildings
Overview of Embedded System Architecture
Every embedded system consists of custom-built hardware built around a Central Processing Unit (CPU). This hardware also contains memory chips onto which the software is loaded. The software residing on the memory chip is also called the ‘firmware’.
The operating system runs above the hardware, and the application software runs above the operating system. The same architecture is applicable to any computer including a desktop computer. However, there are significant differences. It is not compulsory to have an operating system in every embedded system. For small appliances such as remote control units, air conditioners, toys etc., there is no need for an operating system and you can write only the software specific to that application. For applications involving complex processing, it is advisable to have an operating system. In such a case, you need to integrate the application software with the operating system and then transfer the entire software on to the memory chip. Once the software is transferred to the memory chip, the software will continue to run for a long time you don’t need to reload new software
WIRELESS MOBILE CHARGER
Mobile phones becoming a basic part of life, the recharging of mobile phone batteries have always been a problem. The mobile phones vary in their talk time and battery standby according to their manufacturer and batteries. The main objective of this current proposal is to make the recharging of the mobile phones independent of their manufacturer and battery make. In this paper a new proposal has been made so as to make the recharging of the mobile phones is done using induction principle.
This is based on Inductive charging uses and electromagnetic field to transfer energy between two objects. This is usually done with a charging station. Energy is sent through inductive coupling to an electrical device, which then can use that energy to charge batteries. Because there is a small gap between the two coils employed in each of the sender and receiver of the energy within the respective devices, inductive charging is considered a short-distance “wireless” energy transfer despite the fact that there are typically more wires used with inductive charging than direct-contact charging, because it frees the user from having to deal with wires between the two devices. Induction chargers typically use an induction coil to create an alternating electromagnetic field from within a charging base station, and a second induction coil in the portable device takes power from the electromagnetic field and converts it back into electrical current to charge the battery.
Use of embedded technology makes this system efficient and reliable. Micro controller (AT89S52) allows dynamic and faster control. Liquid crystal display (LCD) makes the system user-friendly. AT89S52 micro controller is the heart of the circuit as it controls all the functions.
The project is used in multiple ways such as in securing the mobile from loss or theft as well as it gets charged wirelessly. If anyone wants to steal it automatically a 60 Db siren will get a switched ON. The system is provided with a control switch it has to be made ON such as if the user wants to charge mobile it will be placed on this
Microcontroller
Microprocessors and microcontrollers are widely used in embedded systems products. Microcontroller is a programmable device. As shown in fig 2.4 microcontrollers has a CPU in addition to a fixed amount of RAM, ROM, I/O ports and a timer embedded all on a single chip. The fixed amount of on-chip ROM, RAM and number of I/O ports in microcontrollers makes them ideal for many applications in which cost and space are critical. ATMEL 89s52 is an 8-bit processor, meaning that the CPU can work on only 8 bits of data at a time. Data larger than 8 bits has to be broken into 8-bit pieces to be processed by the CPU.
The present project is implemented on Keil uVision. In order to program the device, proload tool has been used to burn the program onto the microcontroller
RST
Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. This pin drives High for 96 oscillator periods after the Watchdog times out. The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the default state of bit DISRTO, the RESET HIGH out feature is enabled.
ALE/PROG
Address Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode
Induction Charging
Inductive charging uses an electromagnetic field to transfer energy between two objects. This is usually done with a charging station. Energy is sent through inductive coupling to an electrical device, which then can use that energy to charge batteries. Because there is a small gap between the two coils employed in each of the sender and receiver of the energy within the respective devices, inductive charging is considered a short-distance "wireless" energy transfer, despite the fact that there are typically more wires used with inductive charging than direct-contact charging, because it frees the user from having to deal with wires between the two devices.
Induction chargers typically use an induction coil to create an alternating electromagnetic field from within a charging base station, and a second induction coil in the portable device takes power from the electromagnetic field and converts it back into electrical current to charge the battery. The two induction coils in proximity combine to form an electrical transformer. Greater distances can be achieved when the inductive charging system uses resonant inductive coupling.
Wireless energy transfer or wireless power is the transmission of electrical energy from a power source to an electrical load without interconnecting wires. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible. The problem of wireless power transmission differs from that of wireless telecommunications, such as radio. In the latter the proportion of energy received becomes critical only if it is too low for the signal to be distinguished from the background noise. With wireless power, efficiency is the more significant parameter. A large part of the energy sent out by the generating plant must arrive at the receiver or receivers to make the system economical. The most common form of wireless power transmission is carried out using direct induction. Other methods under consideration include resonant magnetic induction or electromagnetic radiation in the form of microwaves or lasers.
LED and LDR Section
LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000 000 ohms, but when they are illuminated with light resistance drops dramatically. When the light level is low the resistance of the LDR is high. This prevents current from flowing to the base of the transistors. Consequently the LED does not light. However, when light shines onto the LDR its resistance falls and current flows into the base of the first transistor and then the second transistor. The LED lights
PROLOAD
Proload is a software which accepts only hex files. Once the machine code is converted into hex code, that hex code has to be dumped into the microcontroller placed in the programmer kit and this is done by the Proload. Programmer kit contains a microcontroller on it other than the one which is to be programmed. This microcontroller has a program in it written in such a way that it accepts the hex file from the keil compiler and dumps this hex file into the microcontroller which is to be programmed. As this programmer kit requires power supply to be operated, this power supply is given from the power supply circuit designed above. It should be noted that this programmer kit contains a power supply section in the board itself but in order to switch on that power supply, a source is required. Thus this is accomplished from the power supply board with an output of 12volts or from an adapter connected to 230 V AC.
Result
The LCD displays ‘MOBILE CHARGING’ when the mobile is getting charged. The mobile when removed while charging the LCD displays “MOBILE NOT CHARGING” with a siren. If anyone wants to steal it, automatically a 60dB siren will get switched ON. If we have forgot to switch OFF the power supply then also the siren will get switched ON. With this the charging of a mobile phone can be done and with the siren we can come to know if the mobile has been theft or not with theft alert system.
Conclusion
This project presents the wireless mobile charger and it is designed and implemented with Atmel 89S52 MCU in embedded system domain. Experimental work has been carried out carefully. The result shows that higher efficiency is indeed achieved using the embedded system. The proposed method is verified to be highly beneficial for the domestic and industrial purpose.
[attachment=66938]
INTRODUCTION
An Embedded System is a combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to perform a specific function.
A good example is the microwave oven. This is in direct contrast to the personal computer in the family room. It too is comprised of computer hardware and software and mechanical components (disk drives, for example). For a well designed embedded system, the existence of the processor and software could be completely unnoticed by the user of the device. Such is the case for a microwave oven or alarm clock. In some cases, it would even be possible to build an equivalent device that does not contain the processor and software. This could be done by replacing the combination with a custom integrated circuit that performs the same functions in hardware. A lot of flexibility is lost when a design is hard-cooled in this way. It is much easier, and cheaper, to change a few lines of software than to redesign a piece of custom hardware.
In the year 1971, Intel introduced the world’s first microprocessor. This chip, the 4004, was designed for use in a line of business calculators. The microcontroller was an overnight success, and its use increased steadily over the next decade. The embedded system market is one of the highest growth areas as these systems are used in very market segment- consumer electronics, office automation, industrial automation, biomedical engineering, wireless communication, data communication, telecommunications, transportation, military and so on.
Wireless technologies
Advances in mobile communications are paving way for many interesting applications using embedded systems. The mobile phone is one of the marvels of the last decade of the 20th century. It is a very powerful embedded system that provides voice communication while we are on the move. The Personal Digital Assistants and the palmtops can now be used to access multimedia services over the Internet. Mobile communication infrastructure such as base station controllers, mobile switching centres are also powerful embedded systems
Security
Security of persons and information has always been a major issue. We need to protect our homes and offices; and also the information we transmit and store. Developing embedded systems for security applications is one of the most lucrative businesses nowadays. Security devices at homes, offices, airports etc. for authentication and verification are embedded systems. Encryption devices are nearly 99 per cent of the processors that are manufactured end up in~ embedded systems. Embedded systems find applications in every industrial segment- consumer electronics, transportation, avionics, biomedical engineering, manufacturing, process control and industrial automation, data communication, telecommunication, defence, security etc. Used to encrypt the data/voice being transmitted on communication links such as telephone lines. Biometric systems using fingerprint and face recognition are now being extensively used for user authentication in banking applications as well as for access control in high security buildings
Overview of Embedded System Architecture
Every embedded system consists of custom-built hardware built around a Central Processing Unit (CPU). This hardware also contains memory chips onto which the software is loaded. The software residing on the memory chip is also called the ‘firmware’.
The operating system runs above the hardware, and the application software runs above the operating system. The same architecture is applicable to any computer including a desktop computer. However, there are significant differences. It is not compulsory to have an operating system in every embedded system. For small appliances such as remote control units, air conditioners, toys etc., there is no need for an operating system and you can write only the software specific to that application. For applications involving complex processing, it is advisable to have an operating system. In such a case, you need to integrate the application software with the operating system and then transfer the entire software on to the memory chip. Once the software is transferred to the memory chip, the software will continue to run for a long time you don’t need to reload new software
WIRELESS MOBILE CHARGER
Mobile phones becoming a basic part of life, the recharging of mobile phone batteries have always been a problem. The mobile phones vary in their talk time and battery standby according to their manufacturer and batteries. The main objective of this current proposal is to make the recharging of the mobile phones independent of their manufacturer and battery make. In this paper a new proposal has been made so as to make the recharging of the mobile phones is done using induction principle.
This is based on Inductive charging uses and electromagnetic field to transfer energy between two objects. This is usually done with a charging station. Energy is sent through inductive coupling to an electrical device, which then can use that energy to charge batteries. Because there is a small gap between the two coils employed in each of the sender and receiver of the energy within the respective devices, inductive charging is considered a short-distance “wireless” energy transfer despite the fact that there are typically more wires used with inductive charging than direct-contact charging, because it frees the user from having to deal with wires between the two devices. Induction chargers typically use an induction coil to create an alternating electromagnetic field from within a charging base station, and a second induction coil in the portable device takes power from the electromagnetic field and converts it back into electrical current to charge the battery.
Use of embedded technology makes this system efficient and reliable. Micro controller (AT89S52) allows dynamic and faster control. Liquid crystal display (LCD) makes the system user-friendly. AT89S52 micro controller is the heart of the circuit as it controls all the functions.
The project is used in multiple ways such as in securing the mobile from loss or theft as well as it gets charged wirelessly. If anyone wants to steal it automatically a 60 Db siren will get a switched ON. The system is provided with a control switch it has to be made ON such as if the user wants to charge mobile it will be placed on this
Microcontroller
Microprocessors and microcontrollers are widely used in embedded systems products. Microcontroller is a programmable device. As shown in fig 2.4 microcontrollers has a CPU in addition to a fixed amount of RAM, ROM, I/O ports and a timer embedded all on a single chip. The fixed amount of on-chip ROM, RAM and number of I/O ports in microcontrollers makes them ideal for many applications in which cost and space are critical. ATMEL 89s52 is an 8-bit processor, meaning that the CPU can work on only 8 bits of data at a time. Data larger than 8 bits has to be broken into 8-bit pieces to be processed by the CPU.
The present project is implemented on Keil uVision. In order to program the device, proload tool has been used to burn the program onto the microcontroller
RST
Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. This pin drives High for 96 oscillator periods after the Watchdog times out. The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the default state of bit DISRTO, the RESET HIGH out feature is enabled.
ALE/PROG
Address Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode
Induction Charging
Inductive charging uses an electromagnetic field to transfer energy between two objects. This is usually done with a charging station. Energy is sent through inductive coupling to an electrical device, which then can use that energy to charge batteries. Because there is a small gap between the two coils employed in each of the sender and receiver of the energy within the respective devices, inductive charging is considered a short-distance "wireless" energy transfer, despite the fact that there are typically more wires used with inductive charging than direct-contact charging, because it frees the user from having to deal with wires between the two devices.
Induction chargers typically use an induction coil to create an alternating electromagnetic field from within a charging base station, and a second induction coil in the portable device takes power from the electromagnetic field and converts it back into electrical current to charge the battery. The two induction coils in proximity combine to form an electrical transformer. Greater distances can be achieved when the inductive charging system uses resonant inductive coupling.
Wireless energy transfer or wireless power is the transmission of electrical energy from a power source to an electrical load without interconnecting wires. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible. The problem of wireless power transmission differs from that of wireless telecommunications, such as radio. In the latter the proportion of energy received becomes critical only if it is too low for the signal to be distinguished from the background noise. With wireless power, efficiency is the more significant parameter. A large part of the energy sent out by the generating plant must arrive at the receiver or receivers to make the system economical. The most common form of wireless power transmission is carried out using direct induction. Other methods under consideration include resonant magnetic induction or electromagnetic radiation in the form of microwaves or lasers.
LED and LDR Section
LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000 000 ohms, but when they are illuminated with light resistance drops dramatically. When the light level is low the resistance of the LDR is high. This prevents current from flowing to the base of the transistors. Consequently the LED does not light. However, when light shines onto the LDR its resistance falls and current flows into the base of the first transistor and then the second transistor. The LED lights
PROLOAD
Proload is a software which accepts only hex files. Once the machine code is converted into hex code, that hex code has to be dumped into the microcontroller placed in the programmer kit and this is done by the Proload. Programmer kit contains a microcontroller on it other than the one which is to be programmed. This microcontroller has a program in it written in such a way that it accepts the hex file from the keil compiler and dumps this hex file into the microcontroller which is to be programmed. As this programmer kit requires power supply to be operated, this power supply is given from the power supply circuit designed above. It should be noted that this programmer kit contains a power supply section in the board itself but in order to switch on that power supply, a source is required. Thus this is accomplished from the power supply board with an output of 12volts or from an adapter connected to 230 V AC.
Result
The LCD displays ‘MOBILE CHARGING’ when the mobile is getting charged. The mobile when removed while charging the LCD displays “MOBILE NOT CHARGING” with a siren. If anyone wants to steal it, automatically a 60dB siren will get switched ON. If we have forgot to switch OFF the power supply then also the siren will get switched ON. With this the charging of a mobile phone can be done and with the siren we can come to know if the mobile has been theft or not with theft alert system.
Conclusion
This project presents the wireless mobile charger and it is designed and implemented with Atmel 89S52 MCU in embedded system domain. Experimental work has been carried out carefully. The result shows that higher efficiency is indeed achieved using the embedded system. The proposed method is verified to be highly beneficial for the domestic and industrial purpose.