Water Level Controller using 89C51 microcontroller

 This project illustrates the construction and working of a water level controller. Such a closed loop system is used in tanks to indicate the level of liquids and take actions autonomously to fill it.

 

Figure 1. Proteus Simulation

Component used:

1. ATMEL 89C51

2.  LCD (LM016L)

3. Switches

4. simple DC Motor

5. Transistor 2n2222

Description:

Water Level Controller circuit works on the principle that water conducts electricity. A wire connected to VCC and four other wires are dipped in tank at different levels namely quarter, half, three-fourth, full and their output are taken on pins P1.1, P1.2, P1.3, P1.4   Port P2 is connected to data pins of LCD and P3.0 , P3.1 and P3.2 are respectively connected to RS, RW, and EN pins of LCD. The DC motor is connected to the P3.7 .

Initially when the tank is empty LCD will show the message EMPTY TANK, 30 MIN TO FILL. When this state is detected by the controller, it immediately switches ON the motor which pumps the water into the tank. As the tank starts filling up wire at different levels get some positive voltage, due to conducting nature of water (it has been shown by switches for simulation purpose).

The switches shown in simulation emulate the water sensors which are placed inside the tank. These sensors on sensing the water, transmits the signal to the controller in form of positive voltage. 

This voltage is then fed to their corresponding pins on controller. When level reaches to quarter level, LCD displays the message QUARTER, 20 MINUTES TO FILL. On further rise of level, HALF, 10 MIN TO FILL and 3/4 FULL, 5 MIN TO FILL are displayed on LCD. When tank gets full LCD shows the message FULL.

DC motor has been interfaced additionally to the microcontroller in such a manner that it will turn on when the tank is EMPTY and will run till the tank is FULL. Transistor is advised to be attached when working in real time conditions in order to avoid back emf generated in the motor, which can harm the microcontroller.

Advantages and Applications:

1. Water level Controller is used in applications like storage tanks, boilers etc. to indicate level of        water inside.

2.  Easily starts and stops the motor.

3. Low cost

Scope:

This circuit not only indicates the amount of water present in the overhead tank but also automatically starts and stops the motor. It helps to check overflow and wastage of water by warning the customer when the tank is about to brim. It also provides automatic control of pumps at a remote location.

1. Now no need to go on the roof to look the water level.

2. It shows the water level in your room like 1/4 tank, 1/2 tank,  3/4 tank and full tank.

3.  Motor stops as soon as tank becomes full.

4.  Suitable for every tank.

Simulation Circuit:

We have simulated the circuit using Proteus, and compiled using Keil.

In order to see the simulation, open the proteus file and upload the hex file in the controller. 

You need four things for running the project:

1. Hex file

2. Proteus simulation file

3. Code text file

4. Keil project file

The code will be available to blog followers upon request.:)