A Brief Description

In this project we have designed an automated water tank management system using solar energy. Here we automatically fill up the tank when it is empty as well as monitor for keeping water at a moderate temperature and all these are done in an energy efficient way.

Required Equipments

  • Arduino Uno Microcontroller

  • Solar Panel

  • 6V rechargable Battery

  • Servo Motor

  • LDR Sensor

  • Temperature Sensor (LM35)

  • DC Motor

  • Some more things to interface the major components:

    • Voltage Regulator (7806)

    • Registors

    • Capacitors

    • Diode

    • Schottky Diode

    • Jumper Wires and Normal Wires

    • LED

    • PNP and NPN Transistors

How it works

In this project Arduino microcontroller is used for interfacing to various hardware peripherals. Our system is an embedded application which automatically fills up water tank when it is empty, monitors the temperature of water and rotates solar panel to track sunlight. We use solar panel during day to provide power to circuits and recharge a battery. The battery is used at night to provide power.

For doing so an Arduino microcontroller is interfaced to two probes to determine water level, a temperature sensor, two LDRs to determine the diretion of sun and a servo motor to rotate solar panel. A rechargable Lead Acid battery is connected to solar panel.

When water drops below the Low probe, motor is turned on to fill up the tank. When water goes above the High probe, motor is turned off.

The resistance of a LDR is proportional to light that falls upon it. Our system uses this property to determine if any LDR is getting more light than the other one. If so, the solar panel is rotated towards the LDR getting more light until both LDRs get same amount of light.

Temperature sensor is used to determine temperature of water. If temperature falls below a certain threshold, a heater is turned on. The heater is turned off when temperature rises above the threshold.

Block Diagram

pin diagram

fig.1 Block Diagram


  1.   Start.
  2.    Do initial configuration of the system.
  3.       Calculate the temperature of water.
  4.       If temperature is below 20 degree Celcius
  5.         Turn on heater.
  6.       Calculate resistance of LDR1 and LDR2
  7.       If resistance of LDR1 is greater than LD2
  8.        Rotate servo motor towards LDR1.
  9.       Else if resistance of LDR2 is greater than LD1
  10.         Rotate servo motor towards LDR2.
  11.       Else
  12.         Keep the servo motor in current position.
  13.       Determine the level of water in tank.
  14.       If water is below Low level
  15.        Turn on motor.
  16.       Else if water is above High level
  17.         Turn off motor.
  18.       Else
  19.         Keep the motor in current state.
  20.     Go back to step 3
  21.   End.

Detailed Pin Diagram

pin diagram

fig.2 Pin Diagram of the System

Problems Faced

  1. The temperature sensor was not working properly at first. We had to change the IC twice. Still outputs were fluctuating with large difference. After using a resistor between the output pin and the ground pin it became stable.

  2. We had a plan to make a heater to keep the water at a moderate temperature always. But heating coils or any heating element needs a lot of power and voltage which was not possible to supply with our one solar panel only. If we could manage multiple solar panels we could make the heater work properly. Though we made a heater which works fine with AC power supply, it was not incorporated with our system as we wanted to make the whole system using solar energy only.

  3. We faced problem with the ldr sensors also. In the same amount of light two ldrs' were showing different outputs. Changing the sensors solved the problem finally.

  4. It was challenging to rotate solar panel using servo motor in order to track sunlight. We had to make a system which supported the weight of solar panel and the servo motor while also enabling the motor to rotate the panel freely in horizotal plane.

  5. We needed constant 5 voltage and 6 voltage supply for circuits. But the voltage from solar panel varies. We had to make additional circuit to get constant voltages.

Group Members Information

Section B1: Group 5

  • Anurata Prabha Hridi (1205030)

  • Esmotara Rima (1205050)

  • Mayisha Alam (1205058)

  • Renascence Tarafder Prapty (1205060)

Course Teachers

  1. Md. Iftekharul Islam Sakib

  2. Ishtiyaque Ahmad

  3. Md. Shariful Islam Bhuyan

Project Video