{"product_id":"kit-evapotranspiration-calculator","title":"Evapotranspiration Calculator","description":"\u003ch1\u003eBuild an Evapotranspiration Calculator with Arduino Mega — Penman-Monteith Precision for Crop Water Needs\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 Advanced\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eBuild Time:\u003c\/strong\u003e 6-8 hrs\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eAge:\u003c\/strong\u003e 18-21\u003c\/span\u003e\n  \u003cspan\u003e\u003cstrong\u003eSkill:\u003c\/strong\u003e Precision agriculture IoT \u0026amp; Penman-Monteith implementation\u003c\/span\u003e\n\u003c\/div\u003e\n\n\u003cp\u003eTurn four environmental variables — temperature, humidity, wind speed, and solar radiation — into the exact daily water requirement of any crop. This kit is built for engineers and researchers who need a hands-on tool to implement the FAO-56 Penman-Monteith equation on an Arduino Mega, transforming raw sensor data into actionable irrigation schedules. Whether it’s a Smart India Hackathon challenge on water scarcity or a B.Tech final-year project on precision farming, you’ll leave with a field-ready prototype that computes evapotranspiration in mm\/day.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Build\u003c\/h2\u003e\n\u003cp\u003eYou will assemble a portable, battery-powered instrument that reads temperature\/humidity (DHT22), light intensity (BH1750), and wind speed via a Hall-effect sensor, then processes them through the Penman-Monteith algorithm. The 1.8-inch TFT displays real-time ET0 values, and every reading gets timestamped with a DS3231 RTC and written to MicroSD — creating a field log usable for irrigation scheduling of crops like wheat, rice, or maize.\u003c\/p\u003e\n\n\u003ch2\u003eWhat You'll Learn\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eImplement the full Penman-Monteith equation in Arduino C++ using variables for net radiation, vapour pressure deficit, and aerodynamic resistance\u003c\/li\u003e\n  \u003cli\u003eInterface multiple I2C and digital sensors (DHT22, BH1750, Hall-effect anemometer) without bus conflicts\u003c\/li\u003e\n  \u003cli\u003eDesign a robust data logging system with RTC timestamping and CSV storage on MicroSD for later analysis in Excel or Python\u003c\/li\u003e\n  \u003cli\u003eCalibrate a DIY anemometer using pulse counting and convert it to wind speed at 2 m height per FAO standards\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 Mega 2560\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDHT22\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eBH1750\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eA3144 Hall Sensor\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1.8in TFT ST7735\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDS3231 RTC\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMicroSD Module\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e10kΩ Resistors\u003c\/td\u003e\n\u003ctd\u003e10\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e100nF Caps\u003c\/td\u003e\n\u003ctd\u003e10\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePCB Prototype Board\u003c\/td\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM-M Wires\u003c\/td\u003e\n\u003ctd\u003e30\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e9V Battery Snap\u003c\/td\u003e\n\u003ctd\u003e1\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 built for B.Tech Agricultural Engineering, ECE, and EEE students developing precision irrigation prototypes at IITs, NITs, VIT, or state agricultural universities. Smart India Hackathon teams tackling water management themes will find every sensor needed for an evapotranspiration monitoring station. Final-year researchers and hobbyist agri-tech innovators get a semester’s worth of embedded systems learning with a real-world environmental monitoring outcome.\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 to access the AI companion trained on this exact kit’s wiring diagram, code, and calibration steps. If you need a human touch, message us on WhatsApp for troubleshooting support within 24 hours.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow do I measure wind speed with the included Hall sensor?\u003c\/summary\u003e\u003cp\u003eThe A3144 detects magnetic pulses from a rotating anemometer (cup assembly not included). The AI companion provides a reference design using scrap materials and walks you through pulse counting, RPM-to-wind speed conversion at standard 2 m height, and calibration against a handheld anemometer.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan this kit compute crop-specific water needs, or only reference ET?\u003c\/summary\u003e\u003cp\u003eThe Penman-Monteith equation gives reference evapotranspiration (ET0). To get crop ET, you multiply by a crop coefficient (Kc). The companion explains Kc stages for Indian crops like rice, wheat, sugarcane, and cotton, and you can input Kc directly in the code.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this suitable for long-term outdoor deployment?\u003c\/summary\u003e\u003cp\u003eWith a 9V battery and MicroSD logging, the unit can run unattended for days. For permanent field use, you’ll need to weatherproof the enclosure (not included) and consider a solar-powered supply. The code is structured to handle sensor failures gracefully and resume logging upon power cycles.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdiv class=\"kit-description\"\u003e\n  \u003cp\u003eTemperature, humidity, wind speed and solar radiation inputs feed a Penman-Monteith equation to compute daily crop water need.\u003c\/p\u003e\n  \u003ch4\u003eWhat's in this kit\u003c\/h4\u003e\n  \u003cul\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/mega-2560-r3-development-board-arduino-compatible-54-io-256kb\"\u003eArduino Mega 2560\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/dht22-temperature-humidity-sensor-module-accurate-readings\"\u003eDHT22\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/gy-30-bh1750fvi-light-intensity-sensor-module-for-arduinoesp\"\u003eBH1750\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/a3144-hall-effect-sensor-unipolar-switch-for-magnetic-sensing\"\u003eA3144 Hall Sensor\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/18-inch-spi-128x160-tft-lcd-display-module-for-arduino\"\u003e1.8in TFT ST7735\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/ds3231-real-time-clock-module-i2c-rtc-with-battery-backup\"\u003eDS3231 RTC\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/microsd-card-reader-spi-module-for-arduino\"\u003eMicroSD Module\u003c\/a\u003e\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\/capacitor-variety-pack-6-values-100nf-to-470uf-30-pieces\"\u003e100nF Caps\u003c\/a\u003e x10\u003c\/li\u003e\n    \u003cli\u003e\n\u003ca href=\"\/products\/esp-wroom-32-breakout-board-pcb-55x52mm\"\u003ePCB Prototype Board\u003c\/a\u003e x2\u003c\/li\u003e\n    \u003cli\u003eM-M Wires x30\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 Evapotranspiration Calculator?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The Evapotranspiration Calculator includes all components needed: Arduino Mega 2560, DHT22, BH1750, A3144 Hall Sensor, 1.8in TFT ST7735 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 Evapotranspiration Calculator?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This kit is designed for Advanced level makers, suitable for ages 18-21. Temperature, humidity, wind speed and solar radiation inputs feed a Penman-Monteith equation to compute daily crop water need. Estimated build time is 6-8 hrs.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I buy the Evapotranspiration Calculator online in India?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, the Evapotranspiration Calculator 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\": \"Evapotranspiration Calculator\",\n  \"description\": \"Temperature, humidity, wind speed and solar radiation inputs feed a Penman-Monteith equation to compute daily crop water need.\",\n  \"sku\": \"CDN-KIT-0127\",\n  \"brand\": {\"@type\": \"Brand\", \"name\": \"Compoden\"},\n  \"offers\": {\n    \"@type\": \"Offer\",\n    \"url\": \"https:\/\/compoden.in\/products\/kit-evapotranspiration-calculator\",\n    \"priceCurrency\": \"INR\",\n    \"price\": \"3050\",\n    \"availability\": \"https:\/\/schema.org\/InStock\",\n    \"seller\": {\"@type\": \"Organization\", \"name\": \"Compoden\"}\n  },\n  \"category\": \"Weather \u0026 Environment\"\n}\n\u003c\/script\u003e\u003cp\u003e\u003cstrong\u003eChoose your assembly option:\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSoldering Kit\u003c\/strong\u003e — 25W soldering iron, 60\/40 solder wire, flux, and small perfboard for permanent assembly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBreadboard Combo\u003c\/strong\u003e — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Compoden","offers":[{"title":"Soldering Kit","offer_id":53459769786733,"sku":"CDN-KIT-0127-SLD","price":4720.0,"currency_code":"INR","in_stock":true},{"title":"Breadboard Combo","offer_id":53459769819501,"sku":"CDN-KIT-0127-BB","price":4190.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/kit-evapotranspiration-calculator.png?v=1781944255","url":"https:\/\/compoden.com\/products\/kit-evapotranspiration-calculator","provider":"Compoden","version":"1.0","type":"link"}