Search This Blog

Photo Resistor (LDR) A Light Dependent Resistor (LDR) is also called a Photoresistor or a cadmium sulfide cell .it is also called a photoconductor. An LDR is a component that has a variable resistance that changes with the light intensity that falls upon it. this allows them to be used in light sensing circuits There are many applications for Light Dependent Resistors. these include Lighting switch the most obvious application for an LDR is to automatically turn on light at a certain light level. An example of this could be an automatic street light or a garden light system Camera shutter control LDRs can be used to control the shutter speed on a camera. the LDR would be used to measure the light intensity which then adjusts the camera shutter speed to the appropriate level the zig-zag structure on the LDR is cadmium sulfide track and two dots are metal film contacts How To Use LDR with Arduino : Circuit Diagram : Arduino Program for Above Circuit : int ldr=A0;//Set A0(Anal

interfacing fingerprint sensor with arduino

- June 02, 2021

OPTICAL FINGERPRINT SENSOR Optical fingerprint sensors take low-resolution snapshots of the tip of a finger and create arrays of identifiers that are then used to uniquely identify a given fingerprint. RED > 5V BLACK > Gnd YELLOW > 2 WHITE > 3 install Adafruit fingerprint library go to manage the library and search fingerprint and click on Adafruit fingerprint library ENROLLING FINGERTIP IMPRESSION : FINGERPRINT LED CONTROLLING : CODE FOR LED : #include <Adafruit_Fingerprint.h> // For UNO and others without hardware serial, we must use software serial... // pin #2 is IN from sensor (YELLOW wire) // pin #3 is OUT from arduino (WHITE wire) // comment these two lines if using hardware serial SoftwareSerial mySerial(11,10); Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial); void setup() { Serial.begin(9600); while (!Serial); // For Yun/Leo/Micro/Zero/... delay(100); Serial.println("\n\nAdafruit f