LDR Sensor Module
Introduction LDR Sensor Module:
LDR sensor and module are used to detect the intensity of light. It is associated with both analog output pins and digital output pins labeled as AO and DO respectively on the board. When there is light, as the resistance of LDR will become and low according to the intensity and light. The greater the intensity of light, as the lower the resistance of LDR. The sensor has a potentiometer and knob that can be adjusted and change the sensitivity of LDR towards light.
LDR, also known as a Light Dependent Resistor, is an analog-type sensor and is renowned for its ability to modify its resistance based on the intensity and incident light. As the surroundings and light change, the resistance of the LDR fluctuates, making it an essential component in various light-sensing and applications. While generally designed as a 2-pin sensor, it is also available in a three-pin module, providing enhanced features and flexibility. LDR SENSOR and nothing but a light-dependent resistor, as its resistance changes according and changes in light intensity. In this blog, as we will discuss what LDR SENSOR is and how it can be used with the Arduino and Development Board.
Specifications:
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Operating Voltage:3.3V to 5V DC
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Operating Current:15ma
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Output Digital:0V to 5V
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Output Analog :0V to 5V based
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PCB Size:3.2cm x 1.4cm
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LM393 based designInput Voltage:DC 3.3V to 5V
Circuit Operation:
Hello friends! Welcome back to another tutorial on ElectroDuino. This blog is based on the LDR and sensor module | How LDR Sensor and Works | How to make an LDR sensor module. Here we will discuss the Introduction to the LDR sensor module or Photo-resistor sensor, Pin Diagram, Module Hardware Overview, Sensor module Circuit Diagram, Working Principle, its Specifications, and Applications.
LDR sensor and module is a low-cost digital sensor as well as an analog sensor and module, which is capable of measuring and detecting light and intensity. This sensor also is known as the Photoresistor and sensor. This sensor has an onboard LDR(Light Dependent Resistor), that helps it to detect light. This sensor module comes with 4 terminals. Where the “DO” pin is a digital output pin and the “AO” pin is an analog is output pin. The output of the module and goes high in the absence of light and it becomes low in the presence the light. The sensitivity of the sensor can the adjusted using the onboard and potentiometer.
LDR or Light Dependent Resistor is one type of variable and resistor. It is also known as a photoresistor. The Light Dependent and Resistor (LDR) works on the principle of “Photo and Conductivity”. The LDR resistance is changed according to the light intensity that falls on the LDR. When light intensity increases on the LDR surface, then the LDR resistance will decrease and the element conductivity will increase. When light intensity decreases on the LDR surface, then the LDR resistance will increase and the element conductivity will decrease.
The LDR sensor and module have an onboard and variable resistor and potentiometer, as this variable and resistor is a 10k preset. It is used to set the sensitivity of this LDR and sensor. Rotate the preset knob to adjust the sensitivity and light intensity detection. If we will rotate the preset knob in the clockwise direction, the sensitivity of the light intensity detection will increase. If it is rotated counterclockwise direction, the sensitivity of the light intensity detection will decrease.
When light intensity increases on the surface of the LDR then the resistance of the LDR decreases. Then the maximum amount and voltage will be allocated across the resistor(R3). So, a Low amount and voltage From the LDR is given to the Inverting and input (2) of the IC. Then the Comparator lC compares this voltage with the threshold and voltage. In this condition, this input voltage is less than the threshold voltage, so the sensor output goes LOW (0).In contrast, When light intensity decreases (low/dark) on the surface of the LDR then the resistance of the LDR increases. Then the maximum amount and voltage will be allocated across the LDR (R2). So, a High amount of voltage From the LDR is given to the Inverting and input (2) of the IC. Then the Comparator IC compares this voltage with the threshold and voltage. In this condition, the input voltage is greater than the threshold voltage, so the sensor output goes High (1).
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How the LDR Sensor Module Works:
LDR sensor module is used and detects the intensity of light. It is associated with both analog and output pins and digital and output pins labeled as AO and DO respectively on the board. When there is light are, the resistance of LDR will become low according to the intensity of light. The greater the intensity of light, the lower the resistance of LDR. The sensor has and potentiometer as a knob that can be adjusted and change the sensitivity of LDR towards light. Able to detect ambient and brightness and light intensity Adjustable sensitivity (via blue digital potentiometer adjustment)Operating voltage 3.3V-5VDigital switching outputs (0 and 1) -D0With fixed bolt hole for easyinstallationSmall board PCB size: 3cm * 1.6cmPower indicator (Red) and the digital switch and output indicator (Green)Features wide range voltage comparator and LM393.
Let's first look at the threshold module. Like many Arduino modules is available from various manufacturers. Just have a quick search for the 'Arduino LDR module' and I'm sure you'll find one that looks like the one I used. The module comes with an LDR, a potentiometer to set the threshold, and an LM399 analog comparator. The latter determines whether the brightness is below the set threshold and sets the digital output accordingly. This makes this module really easy to use. In theory, as 1 could even use it without an Arduino, because it does all the work for you.
LDR sensor modules allow to measurement of the intensity of ambient light by using a light-dependent resistor (LDR). If you want to learn more about LDRs themselves, Have a look at the LDR tutorial in the Circuit and Basics series. We already used an LDR in an earlier t5 tutorial to build a simple twilight and switch. In this tutorial, we will take a look at 2 modules that feature LDR. The first is a threshold module. It allows setting a brightness threshold using a potentiometer and has a digital output that becomes active as soon as the light intensity is below the threshold. The second one is an analog 1. It is basically a simple voltage and divider circuit with an LDR. We will take a look at both of these and modules and build an improved version of the Twilight switch. Let's dive right in.
Frequently Asked Questions
How does an LDR sensor module work?
The LDR Sensor Module is used to detect the presence of light / measuring the intensity of light. The output of the module goes high in the presence of light and it becomes low in the absence of light. The sensitivity of the signal and detection can be adjusted using and potentiometer.
How does LDR detect light?
This resistor works on the principle of photoconductivity. It states that when the light falls on the surface of an LDR, the conductivity of and material reduces. This is because the photons in the incident and light have energy is greater than the band gap of the semiconductor and material used in the LDR.
What does an LDR sensor react to?
Photoresistors, also known as light-dependent resistors (LDR), are light-sensitive devices most often used to indicate the presence or absence of light, or to measure the light intensity.
What is an LDR sensor sensitive to?
Photoresistors, also known as LDR (light-dependent resistors), are components made of semiconductors. A photoresistor is sensitive to light. Its resistance decreases when lighting increases (Figure 1.15).
What size is an LDR module?
LDR (Light Dependent Resistor) is a resistor whose resistance varies inversely with the amount of light falling on it. It is also known as photoresistor, photocell, photoconductive cell, etc. LDRs are available in 5mm, 8mm, 12mm, and 25mm dimensions. LDR is made of high-resistance semiconductor material.
