{"product_id":"kit-auto-light-energy-saver-kit-with-arduino-uno-plus-ldr","title":"Auto Light Energy Saver Kit with Arduino Uno + LDR","description":"\u003ch1\u003eBuild an Auto Light Energy Saver with Arduino Uno, LDR, and PIR Motion Sensor\u003c\/h1\u003e\n\n\u003cp class=\"value-summary\"\u003eEvery part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.\u003c\/p\u003e\n\n\u003cdiv class=\"specs-strip\"\u003e\n  \u003cspan\u003e\u003cstrong\u003eDifficulty:\u003c\/strong\u003e Intermediate\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eBuild Time:\u003c\/strong\u003e 3-4 hrs\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eAge:\u003c\/strong\u003e 15-18\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eSkill:\u003c\/strong\u003e Multi-sensor conditional automation\u003c\/span\u003e\n\u003c\/div\u003e\n\n\u003cp\u003eWith this kit, you’ll build a light controller that never wastes electricity — it only activates when someone enters a dark room and stays off during daylight motion. By combining a passive infrared (PIR) sensor with a light-dependent resistor (LDR), you create a system that mirrors real-world home automation, like in corridors, bathrooms, or storerooms where lights are often left on for hours.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Build\u003c\/h2\u003e\n\u003cp\u003eA fully functional automatic lighting unit that detects human presence and measures ambient brightness to decide when to power a bulb or appliance through the relay. The system displays status on a 16x2 LCD — ‘Motion: YES\/NO’ and ‘Light: LOW\/HIGH’ — giving you clear, real-time feedback as it saves energy.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Learn\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eHow to interface an HC-SR501 PIR module with Arduino to detect motion\u003c\/li\u003e\n  \u003cli\u003eUsing an LDR with a voltage divider to measure ambient light levels digitally\u003c\/li\u003e\n  \u003cli\u003eDriving a 5V relay to safely switch AC loads, with flyback diode protection\u003c\/li\u003e\n  \u003cli\u003eDisplaying real-time sensor data on an I2C LCD and building a clean breadboard circuit\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eKit Contents\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eComponent\u003c\/th\u003e\n\u003cth\u003eQuantity\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Uno R3\u003c\/td\u003e\n\u003ctd\u003ex1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eHC-SR501 PIR\u003c\/td\u003e\n\u003ctd\u003ex1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eLDR\u003c\/td\u003e\n\u003ctd\u003ex2\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e5V Relay Module\u003c\/td\u003e\n\u003ctd\u003ex1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e16x2 LCD\u003c\/td\u003e\n\u003ctd\u003ex1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eI2C Backpack\u003c\/td\u003e\n\u003ctd\u003ex1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1N4007 Diode\u003c\/td\u003e\n\u003ctd\u003ex2\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e10kΩ Resistors\u003c\/td\u003e\n\u003ctd\u003ex10\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e220Ω Resistors\u003c\/td\u003e\n\u003ctd\u003ex5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e400-pt Breadboard\u003c\/td\u003e\n\u003ctd\u003ex1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM-M Wires\u003c\/td\u003e\n\u003ctd\u003ex25\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e9V Battery Snap\u003c\/td\u003e\n\u003ctd\u003ex1\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhy Buy This Kit Instead of Sourcing Parts Separately\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFactor\u003c\/th\u003e\n\u003cth\u003eSourcing Separately\u003c\/th\u003e\n\u003cth\u003eCompoden Kit\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCompatibility checks\u003c\/td\u003e\n\u003ctd\u003eYou verify every part\u003c\/td\u003e\n\u003ctd\u003ePre-tested as a system\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eBuild support\u003c\/td\u003e\n\u003ctd\u003eForums and scattered tutorials\u003c\/td\u003e\n\u003ctd\u003eAI companion trained on this exact project\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTime to first working build\u003c\/td\u003e\n\u003ctd\u003eDays of debugging\u003c\/td\u003e\n\u003ctd\u003eHours, with step-by-step guidance\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eShipping coordination\u003c\/td\u003e\n\u003ctd\u003eMultiple sellers, multiple delays\u003c\/td\u003e\n\u003ctd\u003eOne shipment from Bengaluru in 3-5 days\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWho This Kit Is For\u003c\/h2\u003e\n\u003cp\u003eThis kit is ideal for CBSE Class 11 and 12 students tackling their physics investigatory projects or computer science practicals. B.Tech ECE\/EEE students will find it a ready-made mini project for first-year labs or Smart India Hackathon prep. ATL Tinkering Labs and hobby clubs at IIT, NIT, VIT, or BITS can use it to prototype energy‑conscious automation in a single afternoon.\u003c\/p\u003e\n\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.\u003c\/p\u003e\n\n\u003cdetails\u003e\u003csummary\u003eWhat if I get stuck during the build?\u003c\/summary\u003e\u003cp\u003eScan the QR code on the box to open the AI companion; it walks you through wiring, code, and calibration. If you still have questions, message us on WhatsApp and a real engineer will reply within hours.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWill this kit work with Indian 230V AC appliances?\u003c\/summary\u003e\u003cp\u003eYes. The 5V relay module is rated for up to 250V AC at 10A, and the included 1N4007 diode protects the circuit from back EMF. Always have an adult check high‑voltage connections.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDo I need to solder anything?\u003c\/summary\u003e\u003cp\u003eNo soldering required. All connections use the solderless breadboard and jumper wires. The I2C backpack comes pre‑soldered to the LCD; you just plug in four wires.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs the LDR light threshold adjustable?\u003c\/summary\u003e\u003cp\u003eAbsolutely. You can set the ambient light cutoff in the Arduino code. The AI companion will show you how to change a single variable so lights turn on only when it’s truly dark.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdiv class=\"kit-description\"\u003e\n  \u003cp\u003eEnergy Saving — PIR sensor and LDR together control lighting — only switches on when motion detected AND ambient light is low.\u003c\/p\u003e\n  \u003ch4\u003eWhat's in this kit\u003c\/h4\u003e\n  \u003cul\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/uno-r3-ch340g-atmega328p-board-arduino-compatible\"\u003eArduino Uno R3\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/hc-sr501-pir-motion-sensor-ir-module-combo-for-arduino\"\u003eHC-SR501 PIR\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/ldr-sensor-5mm-light-dependent-resistor-for-arduino-compoden\"\u003eLDR\u003c\/a\u003e x2\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/4-channel-relay-board-for-esp32-30-pin-5v-control\"\u003e5V Relay Module\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/16x2-lcd-display-module-16x2-character-blue-backlight\"\u003e16x2 LCD\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/i2c-backpack-pcf8574-i2c-adapter-for-lcd-displays\"\u003eI2C Backpack\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/diode-variety-pack-1n4007-1n4148-1n5819-zener-assortment\"\u003e1N4007 Diode\u003c\/a\u003e x2\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/resistor-variety-pack-100-pcs-10-values-14w-carbon-film\"\u003e10kΩ Resistors\u003c\/a\u003e x10\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/resistor-variety-pack-100-pcs-10-values-14w-carbon-film\"\u003e220Ω Resistors\u003c\/a\u003e x5\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/breadboard-standard-bundle-830400-tie-points-for-prototyping\"\u003e400-pt Breadboard\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003eM-M Wires x25\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/9v-battery-snap-connector-with-15cm-wires-compoden\"\u003e9V Battery Snap\u003c\/a\u003e\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is included in the Auto Light Energy Saver Kit with Arduino Uno + LDR?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The Auto Light Energy Saver Kit with Arduino Uno + LDR includes all components needed: Arduino Uno R3, HC-SR501 PIR, LDR, 5V Relay Module, 16 and more. Everything is pre-tested for compatibility and shipped from Bengaluru, India.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What skill level is required for the Auto Light Energy Saver Kit with Arduino Uno + LDR?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This kit is designed for Intermediate level makers, suitable for ages 15-18. Energy Saving — PIR sensor and LDR together control lighting — only switches on when motion detected AND ambient light is low. Estimated build time is 3-4 hrs.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I buy the Auto Light Energy Saver Kit with Arduino Uno + LDR online in India?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, the Auto Light Energy Saver Kit with Arduino Uno + LDR is available online at Compoden (compoden.in), India's AI-powered electronics and robotics store. Ships from Bengaluru in 1-5 business days across India.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"Product\",\n  \"name\": \"Auto Light Energy Saver Kit with Arduino Uno + LDR\",\n  \"description\": \"Energy Saving — PIR sensor and LDR together control lighting — only switches on when motion detected AND ambient light is low.\",\n  \"sku\": \"CDN-KIT-2970\",\n  \"brand\": {\"@type\": \"Brand\", \"name\": \"Compoden\"},\n  \"offers\": {\n    \"@type\": \"Offer\",\n    \"url\": \"https:\/\/compoden.in\/products\/kit-auto-light-energy-saver-kit-with-arduino-uno-plus-ldr\",\n    \"priceCurrency\": \"INR\",\n    \"price\": \"1300\",\n    \"availability\": \"https:\/\/schema.org\/InStock\",\n    \"seller\": {\"@type\": \"Organization\", \"name\": \"Compoden\"}\n  },\n  \"category\": \"Home Automation\"\n}\n\u003c\/script\u003e","brand":"Compoden","offers":[{"title":"Clone","offer_id":53463658824045,"sku":"CDN-KIT-2970-CL","price":1560.0,"currency_code":"INR","in_stock":true},{"title":"R3 Original","offer_id":53463658856813,"sku":"CDN-KIT-2970-R3","price":3840.0,"currency_code":"INR","in_stock":true},{"title":"R4 WiFi","offer_id":53463658889581,"sku":"CDN-KIT-2970-R4","price":3200.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/kit-auto-light-energy-saver-kit-with-arduino-uno-plus-ldr.png?v=1781948958","url":"https:\/\/compoden.com\/products\/kit-auto-light-energy-saver-kit-with-arduino-uno-plus-ldr","provider":"Compoden","version":"1.0","type":"link"}