1. LEVEL CONTROL SYSTEM USING MICROCONTROLLER
(8051)

2. OBJECTIVE OF THE PROJECT
In order for the project to success and to be implemented The following objectives have to be achieved are as follows :
To build automatic level control which can be
Use for learning tools in control
To maintain the water in the certain level
To design the programming using microcontroller(8051)
The systems have variable settings in input and display the level in seven segment display.

3. SIGNAL CONDITIONING UNIT
BLOCK DIAGRAM OF THE SYSTEM
PROCESS VARIABLE
CONTROLLING DEVICE
SYSTEM
SENSOR
SIGNAL CONDITIONING UNIT
MICROCONTROLLER
ADC
DAC

4. SYSTEM LAYOUT ADC FLOAT DAC PUMP MICROCONTROLLER RESERVOIR TANK
DISPLAY
MICROCONTROLLER

5. Components Required Tank ADC ( 0808 chip ) Level Sensor (Float) DAC
Pump
89C51 microcontroller
40 pin zip socket
MHz oscillating crystal
9V battery
2 pin pulse switch
LEDs
Vero Board
Soldering Iron
Control Valve
7 Segment Display

6. FLOW CHART
THE WATER LEVEL FROM THE TANK IS SENSED BY THE LEVEL SENSOR
POTENTIOMETER CONVERTS THE LEVEL SENSOR OUTPUT INTO VOLTAGE FORM AND FED TO ADC
DIGITAL OUTPUT FROM ADC IS SENT TO THE MICROCONTROLLER
PUMP
ON ?
YES NO
THE WATER LEVEL FROM THE TANK IS SENSED BY THE LEVEL SENSOR
POTENTIOMETER CONVERTS THE LEVEL SENSOR OUTPUT INTO VOLTAGE FORM AND FED TO ADC
DIGITAL OUTPUT FROM ADC IS SENT TO THE MICROCONTROLLER
PUMP
ON ?
YES NO

7. DIGITAL OUTPUT FROM ADC IS SENT TO THE MICROCONTROLLER
POTENTIOMETER CONVERTS THE LEVEL SENSOR OUTPUT INTO VOLTAGE FORM AND FED TO ADC
DIGITAL OUTPUT FROM ADC IS SENT TO THE MICROCONTROLLER
PUMP
ON ?
YES NO
ADC O/P >
MAX VALUE ?
ADC O/P <
MIN VALUE ?
POTENTIOMETER CONVERTS THE LEVEL SENSOR OUTPUT INTO VOLTAGE FORM AND FED TO ADC
DIGITAL OUTPUT FROM ADC IS SENT TO THE MICROCONTROLLER
YES NO
PUMP
ON ?
ADC O/P >
MAX VALUE ?
ADC O/P <
MIN VALUE ?

8. DIGITAL OUTPUT FROM ADC IS SENT TO THE MICROCONTROLLER
PUMP
ON ?
YES NO
ADC O/P >
MAX VALUE ?
ADC O/P <
MIN VALUE ?
PUMP OFF
PUMP ON
NO ACTION
DIGITAL OUTPUT FROM ADC IS SENT TO THE MICROCONTROLLER
PUMP
ON ?
YES NO
ADC O/P >
MAX VALUE ?
ADC O/P <
MIN VALUE ?
PUMP OFF
PUMP ON
NO ACTION

9. Circuit diagram of interfacing between the microcontroller and the ADC

10. WORK SO FAR

11. DISCUSSION
In our project, we tried our best to perform some practical work. When doing this we faced some problems and we have overcome all problems after calculating a repeated number of times.
First problem we have faced is soldering the circuit.
Secondly ,we face another problem when we are going to solder the microcontroller chip. This problem is solved by installing the zip sockets.
Thirdly, we faced problem while trying to install 8-pin elements and 2-pin elements.We damaged some of LED while testing and we forced to buy other good LED replacing those damaged ones.
Fourthly ,we faced problem while soldering the elements in the Vero board.

12. Scope of the project
The scope of the project is very large and market demand is quite high.
It is very useful for every process in industry as well as in research center and industrial laboratories .
It is also useful for Chemical industries and factories which pack drinks and medicines.

13. Environmental Impact
The components used are very less harmful to the environment .
The gas formed due to unknowingly burning of wire is very less.
Only the burning gas from battery and the motor coil cause a little harm but it is also negligible.
Thus designed control system has almost no bad effect on the environment, except if the subjects remaining of building the prototype are to be thrown in the environment

14. Future Aspect
The unused port of the µC can be implemented for future use.
The whole schematic , that is the level control loop can be designed in a computer so that the total system can be viewed & operated manually when required from a distant location.

15. Conclusion
Software experience is to be gained throughout working on this project on different scale. By doing the project we have got a chance to implement our knowledge we have gained so far in our engineering carrier. Different skills like Team working capabilities, time managing and work managing skill are to be cultured during the project sessions. Learned ethics and lessons .