3.0 HARDWARE AND APPARATUSBelow is the electrical hardware used in this project:NoHardwareQuantityFunction

1Resistor4To limit the current and provide only the required biasing to the vital active parts like the LED, sensors and transistor which are sensitive to high current.

2Infrared (IR) Transmitter2To generate infrared light that transmit infrared signal. Work together with IR receiver as IR sensor to detect presence of object

3Infrared (IR) Receiver2To receive infrared signal. Work together with IR transmitter as IR sensor to sense presence of obstruction.

4TIP 120 transistor1 Used to control and drive DC motor.

5light-emitting diode (LED)2Light up to indicate motor is activated.

6Wire-To connect the electrical component

7Servo motor1Actuation system to control the open and close of the water valve. It is a rotary actuator that enables precise control of angular position of the shaft using coded signal.

8Brush motor 1Actuation system to rotate fan blade. Used in hand dryer system for rotating the fan.

9Arduino1 Microcontroller board to store instruction and implement functions such as logic, sequence, timing and counting to control events. Coding written in Arduino IDE determine how controller should react to certain input and output to be given.

101.5V battery4To provide total 6V power source to power up Arduino board and brush motor.

11Breadboard1Used to create circuit design.

Apparatus:1. Soldering iron2. Soldering holder3. Tin core4. Multi Meter

4.0 METHODOLOGY4.1 Procedure1. The circuit of the control system of the automatic tap control is designed and a schematic diagram is drawn.2. Electrical components are connected according to the schematic diagrams.3. A complete program is written in Arduino IDE 4. The program is transferred to the Arduino.5. 6V power supply is connected to the Arduino and motor.6. The circuit is tested for its functionality and result is observed and recorded. 4.2 Circuit DesignThis automatic tap control system comprises of a servo motor which will open the valve to let water flow when the infrared sensor detects the presence of hands and a fan motor that rotate when the water stop flowing and the infrared sensor senses presence of the hands in front of the fan. Figure 1 below show the circuit for the prototype. Arduino5VPin 9GNDPin 8Pin 6Pin 7Pin A0Pin A15VGNDExternal sourceServo MotorBrush MotorLed 2Led 1TIP 120IR Sensor 2IR Sensor 1

Figure 1: schematic diagram of circuitThe circuit above use Arduino board as the microcontroller. The IR sensors are at pin A0 and pin A1 respectively. These are the sensors used to detect the presence of hands. Servo motor which serves as actuator for controlling valve is at digital pin 9 and brush motor which serves as hand dryer fan is at digital pin 6. LEDs are at digital pin 7 and pin 8 respectively, used to indicate the motor is rotating. When hand is placed near to transmitter of IR sensor 1, signal from the transmitter bounces off the object and into the receiver. Arduino receives the input from IR sensor 1 and activates LED 1 and servo motor to rotate 60 degrees. After hand is removed, the servo motor returns to its original position. Then, when hand is put near to IR sensor 2, same principle occurs and Arduino receives input from IR sensor 2. LED 2 lights up and brush motor starts to rotate until the hand is removed. 4.3 Arduino Code for PrototypeInclude header file for servo motor

#include Servo myservo; int IRpin1 = A0;int IRpin2 = A1;int led1 = 7;int led2 = 8;int motor = 6;

int IR1Read = 0;int count = 0;

void setup() { pinMode(IRpin1, INPUT); pinMode(IRpin2, INPUT); pinMode(led1, OUTPUT); pinMode(led2, OUTPUT); pinMode(motor, OUTPUT); myservo.attach(9);}void loop() { IR1Read = analogRead(IRpin1); if(IR1Read=1) { while((analogRead(IRpin2)>=300)) { digitalWrite(led2, HIGH); analogWrite(motor, 100); } analogWrite(motor, 0); digitalWrite(led2, LOW); } } }

Assign Arduino digital input pin to LEDs, motor and servo motor and analog input pin to IR sensor. Initialize the variables IR1Read and count (for counter)

In the setup function, IR sensor (IRpin1 and IRpin2) is set to be INPUT and motor pin is set to be OUTPUT. LEDs is set to be output. Servo motor variable is attached to pin 9.

When distance of object to IR sensor is close, LED 1 lights up and servo motor rotates to 30 degree. This situation maintains until object is removed from the sensor.

When IR sensor 1 not detecting, servo motor maintain at 90 degree.

After the servo motor is activated once, the IR sensor 2 starts sensing presence of object near it. When object is close to the sensor, LED 2 lights up and brush motor rotates until the object is removed.

4.4 Water Tap Opening MechanismOne of the way to control flow of water through tap is by using solenoid valve. Solenoid valve is an electromechanically operated valve controlled by an electric current through the solenoid. The flow of water is switched on or off in the two port valve. The valve opens when solenoid is energized, hence allows water to flow out. Figure 1 below shows operation of a normally closed solenoid valve. Solenoid valve open

Figure 2: operation of electromechanical solenoid valve

Solenoid valve close

Due to the high cost of the solenoid valve, a mechanism similar to operation of solenoid valve is used instead of the original solenoid valve in this conceptual prototype.

Inlet

Outlet

Figure 3: operation of mechanical solenoid valve

Solenoid valve close. Water is shut off.Solenoid valve open. Water can flow through.

The four bar linkage mechanism is applied. It converts rotation motion of servo motor to linear motion of piston. The piston is lifted to open the valve and lowered to seal off the water inlet by the rotation of servo motor which is controlled by the program stored in Arduino microcontroller

5.0 RESULTThe electrical components and actuator have successfully been assembled and the system works well. When the hand is placed in front of the IR sensor, the servo motor shaft rotates 60 degree from the initial horizontal position. This indicates water flows out of the tap when IR sensor detect the hand. When the hand is removed, the servo motor rotates back to its initial position, which indicates the valve is closed and water stops flowing from tap. After water tap is closed, when the hand is placed in front of the IR sensor of the hand dryer system, the motor (representing hand dryer fan) starts rotating until the hand is removed. OutputsWater flowsFan rotates Correction elementsProcess: tap controller hand dryer systemWater tapHand dryer fanServo motorBrush motorControl Unit(Micro-controller Arduino)InputsProgramClock