06-04-2012, 04:05 PM
TEMPERATURE MONITORING SYSTEM USING MICROCONTROLLER
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INTRODUCTION
Transducers convert physical data such as temperature, light intensity,flow and speed to electrical signals. Depending on the transducer, the transducer, the output produced in the form of voltage, current, resistance, or capacitance. By using temperature transducer we can convert the temperature into electrical pulses. The temperature transducers are also called as temperature sensors.
The temperature sensors are mainly classified as two types.
1. Linear temperature sensors.
2. Non-Linear temperature sensors.
In Linear temperature sensors the output is varied linearly according to the temperature variation at the input.
MICRO-CONTROLLER
Micro –controller unit is constructed with ATMEL 89C51 Micro-controller chip, The ATMEL AT89C51 is a low power, higher performance CMOS 8-bit microcomputer with 4K bytes of flash programmable and erasable read only memory (PEROM). Its high-density non-volatile memory compatible with standard MCS-51 instruction set makes it a powerful controller that provides highly flexible and cost effective solution to control applications.
Micro-controller works according to the program written in it. The program is written in such a way, so that the output from the ADC will be converted into its equivalent voltage and based on the magnitude of the voltage, it calculates the parameter value. Now this magnitude is again digitalized and fed to 7-segment display unit through the latch.
DETAILS ABOUT MICRO CONTROLLER
The Micro controller is a chip, which has a computer processor with all It’s support functions, memory (both program storage and RAM)), and I/O built into the device. These built in functions minimize the need for external circuits and devices to be designed in the final applications.
DIFFERENT TYPES OF MICRO COTROLLERS
Creating applications for micro-controllers is completely different than any other development job in computing and electronic. In most other applications, we probably have a number of sub systems and interfaces already available for our use. This is not the case with a Micro-controller, where we are responsible.
a) Power distribution
b) System clocking
c) Interface design and wiring
EMBEDDED MICRO CONTROLLERS
When all the hardware requires to run the application is provided in the chip, it is referred to as an embedded micro controller. All that is typically required to operate the device is power, reset, and a clock. Digital I/O pins are provided to allow interfacing with external devices. This complete hardware on a chip is extremely useful for some applications.
MICRO-CONTROLLER MEMORY TYPES
Memory is probably not something we normally think about when we create applications for a personal computer. In a micro-controller, understanding how much memory we have and how its architect is critical, especially when we are planning on how to implement the application code. In a micro-controller, memory for different purposes is typically segregated and arranged to allow the device to execute most efficiently.
Micro controller Remote Programming Over a Commercial Telephone Line
The programmer and display application described previously are connected to a phone line via a modem at remote site. Using a personal computer with a modem, a user can upload a new program containing a new message, which is programmed into the AT89C51 embedded in the application. When programming is complete, the application executes the new program, which displays the new message.
Local Station
The local station in the test configuration consists of an IBMPC AT-class computer connected to a Hayes-compatible, Prometheus 1200baud modem. The modem was selected because it was inexpensive and available. A faster modem may be used if desired, although once the file transmission time is reduced below one minute, further reductions in transmission time do not further reduce connect time charges.
Remote Station
The remote station in the test configuration consists of the display application and programmer circuits, described previously, connected to a Hayes-compatible, Prometheus needed I/O pins. This requires that program code and I/O buffers be kept small enough to fit in on-chip memory.
Microcontroller
1200baud modem. During normal operation, the application executes its internal program while the modem and programmer monitor the phone line for incoming calls. After a call has been detected and a connection established, the programmer forces the application to suspend execution of its program.
CONCLUSION:
This project work “Temperature Monitoring System Using Micro controller” is successfully designed, tested and a demonstration module is fabricated. This is a prototype module.
The analog to digital converter employed in the project work is an 8-bit, ADC and it has only 1 channel . We are interfacing the ADC and the LCD display with the Microcontroller AT89C51. We used the ATMEL Microcontroller for constructing this project, because it has FLASH memory and cost of this Microcontroller is very less.