This article is a continuation of the series on “Embedded Sensor –ADXL345” and carries the discussion on Size, Functional Diagram, Pin Configuration, Application, Features and Benefits, ADXL345 Interface accelerometer, and Projects with this accelerometer. This sensor from Analog Devices
Digital output data is formatted as 16-bit twos complement and is accessible through either an SPI (3- or 4-wire) or I2C digital interface.
A proximity sensor is a type of sensor that detects the presence or absence of an object or obstacle in close proximity to it without physical contact. It works by emitting an electromagnetic field or beam of electromagnetic radiation, and then detecting changes in the field or radiation caused by the presence or absence of an object. Proximity sensors are commonly used in various applications such as automatic door openers, touchless faucets, mobile devices for screen activation, and industrial automation for object detection.
This sensor installed on the front of an iPhone 5 next to the earpiece automatically turns off the touchscreen when the sensor comes within a predefined range of an object (such as a human ear) when using the handset.
On Parking Sensor
Ultrasonic parking sensor: Source
Parking sensor on a fender
Type of Proximity
Capacitive Proximity Sensors
Inductive Proximity Sensors
Magnetic Proximity Sensors
Optical Type
Photoelectric
PhotoCell
Infrared Proximity Sensor (Passive Thermal)
Ultrasonic Type
Hall Effect Type
Proximity Sensor Application
Parking sensors, systems mounted on car bumpers that sense distance to nearby cars for parking
Ground proximity warning system for aviation safety
Vibration measurements of rotating shafts in machinery
Top dead centre (TDC)/camshaft sensor in reciprocating engines.
Sheet break sensing in paper machine.
Anti-aircraft warfare
Roller coasters
Conveyor systems
Beverage and food can making lines
Improvised Explosive Devices or IEDs
Mobile devices
Touch screens that come in close proximity to the face
Attenuating radio power in close proximity to the body, in order to reduce radiation exposure
A component widely used in automatic control industry for detecting, controlling, and non-contact switching When proximity switch is close to some target object, it will send out control signal.
Thermistors are temperature-sensing elements made of semiconductor material that has been sintered in order to display large changes in resistance in proportion to small changes in temperature. This resistance can be measured by using a small and measured direct current, or dc, passed through the thermistor in order to measure the voltage drop produced. These solid state temperature sensors actually act like electrical resistors that are temperature sensitive. That is where the name, a clear combination of the words thermal and resistor, comes from. Ametherm specializes in NTC, or negative temperature coefficient, thermistors.
PIR consists of a Pyroelectric sensor which generates energy when exposed to heat.
The module covered with Fresnel Lense Cover.
BISS0001 micro Power PIR Motion Detector IC.
Infrared Application
Passive Infrared Detector for Anti Theft security alarm system.
Passive Infrared Detector based Light On/OFF.
Automatic Light ON/OFF.
Many other motion Detection Application.
Different PIR Modules
The HC-SR501 PIR Sensor Module
Working voltage : 5v to 20V DC
Range : 3 to 7 meters
Induction Lens size: 23mm.
PCB Size: 32mm x24mm.
Pins Details
Ground pin
VCC pin
The output pin detects an object when it is at a high logic level.
Two potentiometers.
One for adjusting the sensitivityof the sensor
Adjust the time for the output signal to stay high when an object is detected from 0.3 seconds up to 5 minutes.
Jumper Settings (Selecting the trigger modes)
non-repeatable trigger – when the sensor output is high and the delay time is over, the output will automatically change from high to low level.
Repeatable trigger – will keep the output high all the time until the detected object is present in sensor’s range
Arduino Example code :
Circuit
Code
/* Arduino PIR Motion Sensor Tutorial */
/* www.ArunEworld.com */
int pirSensor = 8;
int relayInput = 7;
void setup() {
pinMode(pirSensor, INPUT);
pinMode(relayInput, OUTPUT);
}
void loop() {
int sensorValue = digitalRead(pirSensor);
if (sensorValue == HIGH) {
digitalWrite(relayInput, LOW); // The Relay Input works Inversely
}
}
Code Explanation
This Arduino code is for a PIR (Passive Infrared) motion sensor setup, where a relay is controlled based on motion detection. Here’s an explanation of each part:
Section
Explanation
Comments
The code includes comments providing information about the purpose of the code and its source.
Variable Declaration
– pirSensor = 8;: Declares a variable pirSensor and assigns pin 8 to it for reading the PIR sensor’s output. – relayInput = 7;: Declares a variable relayInput and assigns pin 7 to it for controlling the relay.
Setup Function
Initializes the pins: – Sets pirSensor pin as INPUT to receive data from the PIR sensor. – Sets relayInput pin as OUTPUT to control the relay.
Loop Function
– Reads the digital state from the pirSensor pin to check for motion detection. – If motion is detected (sensor value is HIGH), it turns on the relay by setting the relayInput pin LOW.
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