WATER LEVEL INDICATOR AND AUTOMATIC MOTOR SWITCHING SYSTEM

CONTENTS INTRODUCTION BLOCK DIAGRAM MICRO CONTROLLER SENSOR ADC LCD DISPLAY KEYPAD LED’S ULN2003 RELAY DC MOTOR FLOW CHART POWER SUPPLY

INTRODUCTION Water resources are the sources of water , only 1% of water is potentially utilized by human beings. Project deals with conserving water in overhead tanks. Water level in the over head tank is continuously displayed on LCD. Motor is automatically controlled according to the level of the water. Manual switching of motor is carried by using keypad.

BLOCK DIAGRAM Power supply LCD display micro controller LED ULN 2003 ADC sensor ULN 2003 LED LED Key pad motor

MICRO CONTROLLER Microcontrollers these days are silent workers in many apparatus, ranging from the washing machine to the video recorder A marked exception to the above category is the ATMEL 89S52 microcontroller belonging to the ATMEL family A microcontroller is a general purpose device, but that is meant to read the data, perform limited calculations on that data and control its environment based on those calculations. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving

PIN DESCRIPTION 8051 is a 40 – pin chip 32 pins are set for 4 ports P0, P1, P2, P3 Rest of pins are designed as Vcc, GND, XTAL1, XTAL2, RESET, EA, PSEN, and ALE. P0 is interfaced with LCD. P1 is interfaced with ULN-2003. P2 is interfaced with key pad. P3 is interfaced with ADC.

SENSOR The type of sensor we used in our application is potentiometer. A potentiometer , or pot for short , doesn’t change in resistance with temperature like a thermister, or light level like a CdS light dependant resister. It changes with the rotation of a mechanical shaft.. Rotating the shaft changes the resistance between the center and outer two terminals. It'

+SV Vcc GND Vout +5V ADC DB0 DB7 V IN CS 10K RD V REF WR INTR

ADC Signals in the real world are analog signals. Output of the potentiometer is an analog value. This value is compared by the Vref (10k). The converted digital output is given to the micro controller.

MICRO CONTROLLER LCD P0

KEY PAD MICRO CONTROLLER KEY PAD Key pad is used for manual switching of the motor. It is interfaced to the port 2 of micro controller. If key 1 is pressed, the motor will turns ‘ON’. If key 5 is pressed, the motor will turns ‘OFF’. KEY PAD row1 row2 row3 row4 PORT2 col1 col2 col3 col4

LCD When LCD is being interfaced with microcontroller, the data pins of the LCD are connected to port 0. The 8 data pins i.e. pins 7 to pin14 are interfaced with port 0.1 to port 0.7. Pin 0(cathode) and pin 16 (ground) are connected to ground. Pin1 (anode) and pin 15 (Vcc) are given with 5v supply. Pin 4 to pin 6 (EN, RS, RW) are command pins and they are interfaced with port2.5 to port2.7. These pins decide whether the given value is data or command.

MICRO CONTROLLER PORT0

ULN - 2003 ULN-2003 is interfaced to the port 1 of the micro controller. It is used to drive LEDs. It also drives DC motor.

LED A light-emitting diode (LED) is a semiconductor diode that emits incoherent narrow spectrum light when electrically biased in the forward direction of the pn-junction, as in the common LED circuit. This effect is a form of electroluminescence. LEDs are driven by ULN-2003. Green LED indicates that the motor is ‘ON’ . Red LED indicates that the motor is ‘OFF’.  

FLOW CHART NO YES START A SENSE THE WATER LEVEL DISPLAY IF==0 IF==100 MOTOR ON MOTOR OFF A