This project is basically will helps people by saving their electrical energy costs. Besides that, for the people who are busy or rushing they do not need to worried about the electrical appliances that they are forget to switch off .This project is design to save the electricity, saving costs and it also makes the user feel more comfortable and consuming energy. The auto-control brightness lamp, the motion sensor and LDR are used to sense the motion and brightness. Besides that, Arduino UNO also used as the main components for this auto-control brightness lamp circuit. The circuit will detect motion of person, then the LDR will be function to sense the brightness in room and adjust the own resistance.

Step 1: Main Components

- Microcontroller - To control the circuit function based on its code.

- PIR sensor - To detect motion of the people.

- Light Sensor - To detect the intensity of the light in room

- Arduino UNO board

Step 2: Designing the Schematic

The figure above is showing the schematic circuit of auto-control brightness lamp using Proteus Professional 8. For this part, a PIR sensor (Passive infrared resistor) is used to detect the presence of the human and it function as an automatic switch to turn on and turn off the circuit. Besides that, a LDR sensor (Light-Dependent resistor) is used to control the brightness of lamp based on the surrounding light intensity. Furthermore, an Arduino UNO board is function as a main components in this circuit. It is function based on the coding that had been burn and make sure the circuit can function as the result that achieve objective of this project

Step 3: Software Programming ( Arduino UNO )

int ledPin=11;
int ldrIn=0;

int pir=2;

int value=0;

int PIRstate=0;

void setup()

{
  Serial.begin(9600);

pinMode(ledPin, OUTPUT);

pinMode(pir, INPUT);

digitalWrite(ledPin, LOW);
}

void loop()

{
  value=analogRead(ldrIn);

value=constrain(value,990,1010);

value=map(value,990,1010,0,255);

PIRstate=digitalRead(pir);

if(PIRstate==HIGH)

{
    Serial.println(value);

analogWrite(ledPin,value);

delay(10);
  }

else

{   
    analogWrite(ledPin,LOW);
  }
}

Step 4: Simulation

From figures above are showing the simulation of the auto-control brightness lamp circuit in Proteus Professional 8. For the auto-control brightness lamp, PIR is used to detect the presence of human and it will works an automatic switch to switch on or off the circuit. Therefore, when PIR had detect presence of human, the voltage from power supply (+9V) can flow through the circuit. For the part adjust brightness automatically, LDR will function to detect the surrounding light intensity. When the surrounding light intensity is high, a minimum value of voltage which is 0.1V will supply to the output LEDs. While if the surrounding light intensity is low, a maximum value of voltage which is 4.3V will supply to the output LEDs. However, in the simulation, the result can be give only when the surrounding light intensity is high and low. Therefore, based on the figure, we can get the result which are the maximum and minimum voltage for the output LEDs only.

Step 5: Hardware Testing

Auto-control brightness lamp, the PIR sensor will on when it had detect the presence of human. The duration of the PIR is 30 minutes, it will automatic switch off the circuit when it is not presence of human during the time of duration. Besides that, LDR will function to detect the surrounding intensity light and give the amount of voltage to the output LEDs based on it resistance.

LEDs lighted up when the surrounding light intensity is low. Therefore, there is a high voltage will give to the output LEDs and the LEDs can lighted up in the bright condition. Besides that, the LEDs also can lighted up with a low brightness when the weather is cloudy or gloomy. Because the condition of the surrounding still get half in light intensity, and the LEDs had lighted up without a high brightness. Therefore, the output voltage will be reduce then it can help users to save power.