8051 Based Water Level Indicator and Motor Control

Hello friends, This is Anto, in this video you are going to learn, how to make a water level indicator and motor controller. This water level controller monitors the level of the over head tank and automatically switches on the water pump whenever the level goes below a preset limit. The level of the over head tank is indicated using 4 led’s and the pump is switched of when the over head tank is filled. The pump is not allowed to start if the water level in the sump tank is low and also the pump is switched off when the level inside the sump tank goes low during a pumping cycle. The circuit diagram of the water level controller is shown below.

The level sensor probes for the overhead tank are interfaced to the port 2 of the microcontroller through transistors. Have a look at the sensor probe arrangement for the overhead tank in Fig1. A positive voltage supply probe goes to the down bottom of the tank. The probes for sensing 1/4, 1/2, 3/4 and FULL levels are placed with equal spacing one by one above the bottom positive probe

In our project water level is monitored by a transistor concept and when the water level exceeds the level the microcontroller automatically stops the motor.


I strongly suggest you to buy the components from UTSource.net. because in my experience, the quality of the products are good. and also ON TIME Delivery. If you need quality PCB, they will afford at low cost from double side to multilayer. No minimum requirement.

Materials required:-

1) 89c51

2)8051 developement board

3) BC547


5)10k resistor

6)220E resistor

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Gather the Required Components

I have used 8051 development board which have builtin power supply module like bridge rectifier, filter, +5v voltage regulator, +5v terminals, +12v terminals so that i can able to connect the external peripherals easily with the hardware. i can also interface the LCD on the development board without any breakout board

Step 2: Circuit Diagram and the Block Diagram

Connect the hardware as per the circuit diagram, because i have designed the schematic as per the development board schematic. i have split ted the hardware circuit into two divisions. One for the water level testing circuit, another one is the micro-controller unit. combine the circuits and made it as a hardware. i never mentioned about the motor on the schematic. you can understand in the code that where to connect the motor on the hardware.

Step 3: Test the Circuit Manually Without Microcontroller As I Tested

Take a plastic bottle and fill it with water. connect the pins on the plastic bottle. now decrease the water in the bottle. now you can observe the led indications to ON condition when their is a lack of water. now you can connect the collector terminal to the microcontroller

Step 4: Download the Program Using the Programmer

Open the embedded code using KEIL uVision cross compiler.

Edit the code for your suitable changes

compile the code and generate the machine language.

download the code using the willpro software

Step 5: Test the Output

Test the output on the hardware. decrease the level of water on the bottle. now you can observe the status of water is LOW or MEDIUM or HIGH in the LCD display.. for queries... comment me..

Be the First to Share


    • Made with Math Contest

      Made with Math Contest
    • Multi-Discipline Contest

      Multi-Discipline Contest
    • Robotics Contest

      Robotics Contest