{"id":53370,"date":"2017-04-12T23:48:19","date_gmt":"2017-04-12T22:48:19","guid":{"rendered":"https:\/\/www.microplanet.ma\/?post_type=product&#038;p=53370"},"modified":"2026-10-19T18:47:09","modified_gmt":"2026-10-19T18:47:09","slug":"ldr-photoresistor-light-sensor-module","status":"publish","type":"product","link":"https:\/\/www.microplanet.ma\/en\/produit\/ldr-photoresistor-light-sensor-module\/","title":{"rendered":"LDR Photoresistor Light Sensor Module"},"content":{"rendered":"<h3>LDR Photoresistor Light Sensor Module<\/h3>\n<p>This light-sensor module uses a photoresistor (LDR) to respond to ambient light. It includes an LM393 comparator and provides an analog output that varies with the divider voltage and a digital output whose threshold can be adjusted with the onboard potentiometer.<\/p>\n<h4>\ud83d\udd27 Listed specifications<\/h4>\n<ul>\n<li>Operating voltage: 3.3\u20135 V DC<\/li>\n<li>Analog output (A0): varies with the sensed light level<\/li>\n<li>Digital output (D0): switches state around the potentiometer-set threshold; output polarity depends on module configuration<\/li>\n<li>Comparator: LM393<\/li>\n<li>Dimensions: 31 \u00d7 14 mm<\/li>\n<li>Indicators: power LED and output LED (as listed)<\/li>\n<li>Mounting hole: 3 mm<\/li>\n<\/ul>\n<h4>\u2699\ufe0f How it works<\/h4>\n<p>The LDR\u2019s resistance changes with illumination. Together with the board\u2019s resistors it forms a divider, so A0 changes as ambient light changes. The LM393 compares the divider signal with the threshold set by the potentiometer and switches D0 when the threshold is crossed. The analog direction and digital HIGH\/LOW behavior can vary with the board circuit and adjustment.<\/p>\n<h4>\ud83d\udca1 Applications<\/h4>\n<ul>\n<li>Automatic lighting prototypes<\/li>\n<li>Light\/dark alarms<\/li>\n<li>Home-automation experiments<\/li>\n<li>Light-following or light-detecting robots<\/li>\n<li>Light measurement and control projects<\/li>\n<\/ul>\n<h4>\ud83d\udccc Pinout<\/h4>\n<ul>\n<li><strong>VCC:<\/strong> 3.3\u20135 V DC supply<\/li>\n<li><strong>GND:<\/strong> ground<\/li>\n<li><strong>D0:<\/strong> comparator digital output (TTL-level)<\/li>\n<li><strong>A0:<\/strong> analog divider output<\/li>\n<\/ul>\n<h4>\ud83d\udd0c Basic Arduino Uno example<\/h4>\n<p>Connect VCC and GND to the module supply, D0 to Arduino D2, and A0 to Arduino A0. The original code sample is preserved below; adjust the threshold potentiometer to suit the environment.<\/p>\n<pre class=\"prism undefined-numbers lang-cpp\" data-lang=\"C++\"><code>const int analogPin = A0; \/\/ Broche analogique pour la photor\u00e9sistance\r\nconst int digitalPin = 2; \/\/ Broche digitale pour la photor\u00e9sistance\r\nconst int ledPin = 13; \/\/ Broche de la LED int\u00e9gr\u00e9e\r\n\r\n\r\nvoid setup() {\r\n\u00a0 Serial.begin(9600); \/\/ Initialiser la communication s\u00e9rie\r\n\u00a0 pinMode(digitalPin, INPUT); \/\/ Configurer la broche digitale comme entr\u00e9e\r\n\u00a0 pinMode(ledPin, OUTPUT); \/\/ Configurer la broche LED comme sortie\r\n}\r\n\r\n\r\nvoid loop() {\r\n\u00a0 int analogValue = analogRead(analogPin); \/\/ Lire la valeur analogique\r\n\u00a0 int digitalValue = digitalRead(digitalPin); \/\/ Lire la valeur digitale\r\n\r\n\r\n\u00a0 Serial.print(\"Analog value: \");\r\n\u00a0 Serial.print(analogValue); \/\/ Afficher la valeur analogique\r\n\u00a0 Serial.print(\" | Digital value: \");\r\n\u00a0 Serial.println(digitalValue); \/\/ Afficher la valeur digitale\r\n\r\n\r\n\u00a0 if (digitalValue == LOW) { \/\/ Si la sortie digitale est basse\r\n\u00a0 \u00a0 digitalWrite(ledPin, HIGH); \/\/ Allumer la LED\r\n\u00a0 } else {\r\n\u00a0 \u00a0 digitalWrite(ledPin, LOW); \/\/ \u00c9teindre la LED\r\n\u00a0 }\r\n\r\n\r\n\u00a0 delay(500); \/\/ Attendre 500 ms avant de refaire une lecture\r\n}<\/code><\/pre>\n<h4>What the basic code does<\/h4>\n<p>The sketch reads the analog and digital outputs, reports them over serial, and switches the Arduino\u2019s built-in LED according to the digital output state.<\/p>\n<h4>Components for the basic example<\/h4>\n<ul>\n<li>Arduino Uno<\/li>\n<li>LDR light-sensor module<\/li>\n<li>Connecting wires<\/li>\n<\/ul>\n<h4>Connections shown by the example<\/h4>\n<ul>\n<li><strong>VCC:<\/strong> Arduino 3.3 V or 5 V, within module rating<\/li>\n<li><strong>GND:<\/strong> Arduino GND<\/li>\n<li><strong>D0:<\/strong> Arduino D2<\/li>\n<li><strong>A0:<\/strong> Arduino A0<\/li>\n<\/ul>\n<h4>\ud83d\udcdf Advanced example: I2C LCD<\/h4>\n<p>The original LCD code sample is preserved below. It displays the analog reading and a light\/dark indication, and also reports values over serial.<\/p>\n<pre class=\"prism undefined-numbers lang-cpp\" data-lang=\"C++\"><code>#include &lt;Wire.h&gt;\r\n#include &lt;LiquidCrystal_I2C.h&gt;\r\n\r\n\r\nconst int analogPin = A0; \/\/ Broche analogique pour la photor\u00e9sistance\r\nconst int digitalPin = 2; \/\/ Broche digitale pour la photor\u00e9sistance\r\nLiquidCrystal_I2C lcd(0x27, 16, 2); \/\/ Adresse I2C 0x27, \u00e9cran 16x2\r\n\r\n\r\nvoid setup() {\r\n\u00a0 lcd.begin(); \/\/ Initialiser l'\u00e9cran LCD\r\n\u00a0 lcd.backlight(); \/\/ Allumer le r\u00e9tro\u00e9clairage de l'\u00e9cran LCD\r\n\u00a0 Serial.begin(9600); \/\/ Initialiser la communication s\u00e9rie\r\n\u00a0 pinMode(digitalPin, INPUT); \/\/ Configurer la broche digitale comme entr\u00e9e\r\n}\r\n\r\n\r\nvoid loop() {\r\n\u00a0 int analogValue = analogRead(analogPin); \/\/ Lire la valeur analogique\r\n\u00a0 int digitalValue = digitalRead(digitalPin); \/\/ Lire la valeur digitale\r\n\r\n\r\n\u00a0 lcd.setCursor(0, 0);\r\n\u00a0 lcd.print(\"Luminosite: \");\r\n\u00a0 lcd.print(analogValue); \/\/ Afficher la valeur analogique sur l'\u00e9cran LCD\r\n\r\n\r\n\u00a0 lcd.setCursor(0, 1);\r\n\u00a0 lcd.print(\"Etat: \");\r\n\u00a0 if (digitalValue == LOW) {\r\n\u00a0 \u00a0 lcd.print(\"Clair\");\r\n\u00a0 } else {\r\n\u00a0 \u00a0 lcd.print(\"Sombre\");\r\n\u00a0 }\r\n\r\n\r\n\u00a0 Serial.print(\"Analog value: \");\r\n\u00a0 Serial.print(analogValue); \/\/ Afficher la valeur analogique sur le moniteur s\u00e9rie\r\n\u00a0 Serial.print(\" | Digital value: \");\r\n\u00a0 Serial.println(digitalValue); \/\/ Afficher la valeur digitale sur le moniteur s\u00e9rie\r\n\r\n\r\n\u00a0 delay(500); \/\/ Attendre 500 ms avant de refaire une lecture\r\n}<\/code><\/pre>\n<h4>Components for the advanced example<\/h4>\n<ul>\n<li>Arduino Uno<\/li>\n<li>LDR light-sensor module<\/li>\n<li>1602 I2C LCD<\/li>\n<li>Connecting wires<\/li>\n<\/ul>\n<h4>Connections shown by the example<\/h4>\n<ul>\n<li><strong>VCC \/ GND:<\/strong> module supply and common ground<\/li>\n<li><strong>D0:<\/strong> Arduino D2<\/li>\n<li><strong>A0:<\/strong> Arduino A0<\/li>\n<li><strong>LCD SDA \/ SCL:<\/strong> Arduino A4 \/ A5 on the Uno<\/li>\n<\/ul>\n<p>Adjust the potentiometer while observing D0 to set the switching threshold. Use A0 for a varying light-level reading; calibrate your own threshold because ambient light, sensor tolerance and board configuration affect the values.<\/p>\n<h4>\ud83d\udcda Libraries<\/h4>\n<p>The sensor itself does not require a library. The LCD example uses the standard <code>Wire<\/code> library and a compatible <code>LiquidCrystal_I2C<\/code> library, installable through the Arduino IDE Library Manager.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>LDR light-sensor module with an LM393 comparator, analog light-level output and adjustable digital threshold output. Runs from 3.3\u20135 V DC.<\/p>\n","protected":false},"featured_media":53371,"template":"","meta":[],"product_brand":[],"product_cat":[314,316],"product_tag":[],"class_list":["post-53370","product","type-product","status-publish","has-post-thumbnail","product_cat-developpement-en","product_cat-modules-capteurs-en","first","instock","taxable","shipping-taxable","purchasable","product-type-simple"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>LDR Photoresistor Light Sensor Module | MicroPlanet<\/title>\n<meta name=\"description\" content=\"LDR light-sensor module with LM393 comparator, analog and adjustable digital outputs, 3.3\u20135 V supply and Arduino examples.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" 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