27-01-2012, 12:42 PM
AUTOMATED TRAIN USING 8051
INTRODUCTION
A simple way to keep one interested in learning is to have them work with familiar systems in new and interesting ways. Our idea was to design a project that could be used as a tool to learn about micro-controllers. The train controller allows us to get hands on experience with programming the 89C51, while exploring the concepts of stepper motor, lcd display, voltage regulators and 555 timers.
The following slides show how we can implement a train prototype mounted on a simple cardboard using microcontrollers and programming it to control stepper motor, lcd display, and other hardware.
FUNCTIONING
THE FINAL PROJECT WORKS IN A VERY SIMPLE WAY.
ALL WE NEED TO DO IS JUST TO PUSH A RESET BUTTON ON THE TRAIN AND THE FUNCTIONING WILL START.
THERE WUD BE A DISPLAY ON LCD SCREEN SHOWING THE CURRENT STATION.
ONCE THE DISPLAY IS OVER, THE TRAIN WILL START.
AFTER SOME TIME, THE TRAIN STOPS AND THE LCD DISPLAY SHOWS THE NAME OF NEXT STATION.
THIS REPEATS FOR 3 STATIONS UNTIL THE TRAIN COMES IN A REVERSE DIRECTION.
IT CONTINUES TO DO SO IN A TO AND FRO MOTION( JUST LIKE A METRO TRAIN), UNTIL WE RESET THE TRAIN AGAIN OR WE SWITCH OFF THE TRAIN.
WHAT WE SAW UNTIL NOW WAS THE FUNCTIONALITY OF THE END PRODUCT. NOW WE WILL SEE HOW EXACTLY THIS IS HAPPENING AND WHAT ARE THE HARDWARES AND SOFTWARE INVOLVED..
THE INTERNAL FUNCTIONALITY
THE WHOLE CIRCUIT IS IMPLEMENTED USING 89C51 MICROCONTROLLER WHICH IS PROGRAMMED IN A PREDEFINED MANNER.
FIRST OF ALL THE MICROCONTROLLER IS TO BE RESET.
WHEN IT INITIALIZES, IT GOES ON TO ACTIVATE THE LED DISPLAY
THE LED DISPLAY DISPLAYS THE OUTPUT, THAT HAS BEEN PROGRAMMED INTO MC, ON ITS SCREEN.
ONCE THE ENTIRE DISPLAY IS FINISHED, THE CONTROL IS TRANSFERRED TO THE STEPPER MOTOR.
THE STEPPER MOTOR STARTS ROTATING AND ALONG WITH IT WE CAN MOVE OUR TRAIN IN THE FORWARD DIRECTION.
THE STEPPER MOTOR MOVES FOR A CERTAIN AMOUNT OF TIME WHICH CAN BE PROGRAMMED USING A DELAY LOOP.
IN THIS WAY, AFTER A CERTAIN POINT OF TIME, THE TRAIN STOPS, AND THE CONTROL IS AGAIN TRANSFERRED TO THE LCD DISPLAY, WHICH FIRST CLEARS THE PREVIOUS SCREEN AND THEN DISPLAYS THE NAME OF THE SECOND STATION THAT HAS BEEN PROGRAMMED INTO THE MICROCONTROLLER.
IN THIS WAY THE TRAIN GOES TO 3 STATIONS AND THEN IT COMES BACK IN A REVERSE ORDER DISPLAYING THE NAMES OF THE STATIONS IN THE REVERSE ORDER.
AFTER REACHING THE FIRST STATION IT AGAIN REPEATS THE SAME PROCEDURE.
WE CAN INCLUDE ONE ADDED FUNCTIONALITY IN THE WAY THAT THE TRAIN STOPS WHENEVER IT SENSES SOMEONE IN FRONT OF IT.
THIS CAN BE DONE BY USING AN INFRARED TRANSISTOR WHICH KEEPS ON EMITTING IR RAYS.
ONCE THERE IS AN OBSTACLE IN FRONT OF IT, THE RAYS ARE REFLECTED TO THE RECEIVER TRANSISTOR WHICH THEN GOES ON TO BREAK THE CONNECTION BETWEEN STEPPER MOTOR AND POWER SOURCE.
THIS WAY THE TRAIN DOES NOT MOVE UNTIL THE OBSTACLE IS IN FRONT OF IT.
AS SOON AS RECEIVER STOPS RECEIVING IR RAYS, THE CIRCUIT IS RE-ESTABLISHED AND THE STEPPER MOTOR STARTS MOVING AGAIN.
HARDWARE USED
IN THE COMING SLIDES, WE GIVE A BRIEF INTRODUCTION OF THE HARDWARE WE ARE USING.
8051 MICROCONTROLLER
WE ARE USING THE COMMONLY AVAILABLE MC 89C51 SESIGNED BY ATMEL.
The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications.
VOLTAGE REGULATORS
A regulated voltage source is one in which the voltage is constant, and independent of the current flowing through the load from the voltage source. Although a Zener diode can be used to provide a regulated voltage, it is often more convenient to employ a voltage regulator device. These are integrated circuits on a silicon chip, inside a case having three leads. The performance of such voltage regulators is far superior to that of zener diodes, and they are commonly used in power supply circuits .
Type 78xx are positive voltage regulators, and 79xx are negative regulators. If the device is labelled 7805, the output voltage is 5VDC. If the number is 7912, then it means device is negative regulator and output is 12 VDC.
In our project we have used 7805 to give 5V output supply to LCD.
INTRODUCTION
A simple way to keep one interested in learning is to have them work with familiar systems in new and interesting ways. Our idea was to design a project that could be used as a tool to learn about micro-controllers. The train controller allows us to get hands on experience with programming the 89C51, while exploring the concepts of stepper motor, lcd display, voltage regulators and 555 timers.
The following slides show how we can implement a train prototype mounted on a simple cardboard using microcontrollers and programming it to control stepper motor, lcd display, and other hardware.
FUNCTIONING
THE FINAL PROJECT WORKS IN A VERY SIMPLE WAY.
ALL WE NEED TO DO IS JUST TO PUSH A RESET BUTTON ON THE TRAIN AND THE FUNCTIONING WILL START.
THERE WUD BE A DISPLAY ON LCD SCREEN SHOWING THE CURRENT STATION.
ONCE THE DISPLAY IS OVER, THE TRAIN WILL START.
AFTER SOME TIME, THE TRAIN STOPS AND THE LCD DISPLAY SHOWS THE NAME OF NEXT STATION.
THIS REPEATS FOR 3 STATIONS UNTIL THE TRAIN COMES IN A REVERSE DIRECTION.
IT CONTINUES TO DO SO IN A TO AND FRO MOTION( JUST LIKE A METRO TRAIN), UNTIL WE RESET THE TRAIN AGAIN OR WE SWITCH OFF THE TRAIN.
WHAT WE SAW UNTIL NOW WAS THE FUNCTIONALITY OF THE END PRODUCT. NOW WE WILL SEE HOW EXACTLY THIS IS HAPPENING AND WHAT ARE THE HARDWARES AND SOFTWARE INVOLVED..
THE INTERNAL FUNCTIONALITY
THE WHOLE CIRCUIT IS IMPLEMENTED USING 89C51 MICROCONTROLLER WHICH IS PROGRAMMED IN A PREDEFINED MANNER.
FIRST OF ALL THE MICROCONTROLLER IS TO BE RESET.
WHEN IT INITIALIZES, IT GOES ON TO ACTIVATE THE LED DISPLAY
THE LED DISPLAY DISPLAYS THE OUTPUT, THAT HAS BEEN PROGRAMMED INTO MC, ON ITS SCREEN.
ONCE THE ENTIRE DISPLAY IS FINISHED, THE CONTROL IS TRANSFERRED TO THE STEPPER MOTOR.
THE STEPPER MOTOR STARTS ROTATING AND ALONG WITH IT WE CAN MOVE OUR TRAIN IN THE FORWARD DIRECTION.
THE STEPPER MOTOR MOVES FOR A CERTAIN AMOUNT OF TIME WHICH CAN BE PROGRAMMED USING A DELAY LOOP.
IN THIS WAY, AFTER A CERTAIN POINT OF TIME, THE TRAIN STOPS, AND THE CONTROL IS AGAIN TRANSFERRED TO THE LCD DISPLAY, WHICH FIRST CLEARS THE PREVIOUS SCREEN AND THEN DISPLAYS THE NAME OF THE SECOND STATION THAT HAS BEEN PROGRAMMED INTO THE MICROCONTROLLER.
IN THIS WAY THE TRAIN GOES TO 3 STATIONS AND THEN IT COMES BACK IN A REVERSE ORDER DISPLAYING THE NAMES OF THE STATIONS IN THE REVERSE ORDER.
AFTER REACHING THE FIRST STATION IT AGAIN REPEATS THE SAME PROCEDURE.
WE CAN INCLUDE ONE ADDED FUNCTIONALITY IN THE WAY THAT THE TRAIN STOPS WHENEVER IT SENSES SOMEONE IN FRONT OF IT.
THIS CAN BE DONE BY USING AN INFRARED TRANSISTOR WHICH KEEPS ON EMITTING IR RAYS.
ONCE THERE IS AN OBSTACLE IN FRONT OF IT, THE RAYS ARE REFLECTED TO THE RECEIVER TRANSISTOR WHICH THEN GOES ON TO BREAK THE CONNECTION BETWEEN STEPPER MOTOR AND POWER SOURCE.
THIS WAY THE TRAIN DOES NOT MOVE UNTIL THE OBSTACLE IS IN FRONT OF IT.
AS SOON AS RECEIVER STOPS RECEIVING IR RAYS, THE CIRCUIT IS RE-ESTABLISHED AND THE STEPPER MOTOR STARTS MOVING AGAIN.
HARDWARE USED
IN THE COMING SLIDES, WE GIVE A BRIEF INTRODUCTION OF THE HARDWARE WE ARE USING.
8051 MICROCONTROLLER
WE ARE USING THE COMMONLY AVAILABLE MC 89C51 SESIGNED BY ATMEL.
The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications.
VOLTAGE REGULATORS
A regulated voltage source is one in which the voltage is constant, and independent of the current flowing through the load from the voltage source. Although a Zener diode can be used to provide a regulated voltage, it is often more convenient to employ a voltage regulator device. These are integrated circuits on a silicon chip, inside a case having three leads. The performance of such voltage regulators is far superior to that of zener diodes, and they are commonly used in power supply circuits .
Type 78xx are positive voltage regulators, and 79xx are negative regulators. If the device is labelled 7805, the output voltage is 5VDC. If the number is 7912, then it means device is negative regulator and output is 12 VDC.
In our project we have used 7805 to give 5V output supply to LCD.