Summary of Automatic Door Opener using Arduino
This Arduino-based project replicates an automatic door opener using a PIR sensor to detect human motion via infrared energy. When motion is detected, the sensor triggers the Arduino Uno to activate a motor driver, opening the door. The system includes an LCD for display and uses a CD case as the door mechanism.
Parts used in the Automatic Door Opener:
- Arduino UNO
- 16x2 LCD
- PIR Sensor
- Connecting wires
- Bread board
- 1 k resistor
- Power supply
- Motor driver
- CD case (DVD Troly)
You must have seen automatic door openers in shopping malls and other commercial buildings. They open the door when someone comes near the entrance and close it after sometime. A number of technologies are available to make such kinds of systems like PIR sensors, Radar sensors, Laser sensors, Infrared sensors, etc. In this arduino based project, we have tried to replicate the same system by using a PIR sensor.
It uses a motion-detecting sensor (PIR sensor) to open or close the door which detects the infrared energy omitted from human’s body. When someone comes in front of the door, the infrared energy detected by the sensor changes and it triggers the sensor to open the door whenever someone approaches the door. The signal is further sent to arduino uno that controls the door.
Circuit Components
- Arduino UNO
- 16×2 LCD
- PIR Sensor
- Connecting wires
- Bread board
- 1 k resistor
- Power supply
- Motor driver
- CD case (DVD Troly)
PIR Sensor
PIR sensor detects any change in heat, and whenever it detects any change, its output PIN becomes HIGH. They are also referred as Pyroelectric or IR motion sensors.
Here we should note that every object emits some amount of infrared when heated. Human also emits infrared because of body heat. PIR sensors can detect small amount of variation in infrared. Whenever an object passes through the sensor range, it produces infrared because of the friction between air and object, and get caught by PIR.
The main component of PIR sensor is Pyroelectric sensor shown in figure (rectangular crystal behind the plastic cap). Along with BISS0001 (“Micro Power PIR Motion Detector IC”), some resistors, capacitors and other components used to build PIR sensor. BISS0001 IC take the input from sensor and does processing to make the output pin HIGH or LOW accordingly.
Pyroelectric sensor divide in two halves, when there is no motion, both halves remain in same state, means both senses the same level of infrared. As soon as somebody enters in first half, the infrared level of one half becomes greater than other, and this causes PIRs to react and makes the output pin high.
Pyroelectric sensor is covered by a plastic cap, which has array of many Fresnel Lens inside. These lenses are curved in such a manner so that sensor can cover a wide range.
Read More: Automatic Door Opener using Arduino
- How does the PIR sensor trigger the door?
The sensor detects changes in infrared energy emitted by the human body, causing its output pin to go HIGH. - What component controls the door after the sensor detects motion?
The Arduino Uno receives the signal from the PIR sensor and controls the door operation. - What is inside the plastic cap of the PIR sensor?
The cap contains an array of many Fresnel Lenses designed to help the sensor cover a wide range. - Does every object emit infrared energy?
Yes, every object emits some amount of infrared when heated, including humans due to body heat. - What happens to the two halves of the Pyroelectric sensor when no motion occurs?
Both halves remain in the same state and sense the same level of infrared energy. - Which IC processes the input from the Pyroelectric sensor?
The BISS0001 Micro Power PIR Motion Detector IC takes the input and processes it to set the output pin HIGH or LOW. - What causes the PIR sensor to react when someone enters?
When a person enters the first half of the sensor, the infrared level of that half becomes greater than the other, triggering a reaction. - Can this system use technologies other than PIR sensors?
Yes, other technologies like Radar sensors, Laser sensors, and Infrared sensors are available for such systems.
