{"product_id":"kit-cable-length-tdr-estimator","title":"Cable Length TDR Estimator Kit with Arduino Uno + LED","description":"\u003ch1\u003eCable Length TDR Estimator Kit with Arduino Uno \u0026amp; OLED – Build a DIY Time Domain Reflectometer\u003c\/h1\u003e\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\u003cdiv class=\"specs-strip\"\u003e\n  \u003cspan\u003e\u003cstrong\u003eDifficulty:\u003c\/strong\u003e Beginner\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 Time-domain reflectometry \u0026amp; pulse timing\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cp\u003eEver needed to know the exact length of a coaxial cable run without unspooling it? This Cable Length TDR Estimator Kit lets you build a working instrument that sends a fast pulse down a cable, captures the reflection time with microsecond precision, and displays the estimated length on an OLED. It’s a practical tool for antenna setups, networking, or physics lab experiments.\u003c\/p\u003e\n\u003ch2\u003eWhat You'll Build\u003c\/h2\u003e\n\u003cp\u003eA portable, battery-powered TDR device that shows cable length in metres on a crisp 0.96‑inch OLED. The 74HC14 Schmidt trigger sharpens the outgoing pulse, the Arduino Uno’s input capture measures the round‑trip delay, and the pre‑loaded formula converts time to distance using the cable’s velocity factor. The included 3‑metre coaxial cable lets you calibrate and verify before testing unknown lengths.\u003c\/p\u003e\n\u003ch2\u003eWhat You'll Learn\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003ePrecision timing with Arduino’s input capture unit\u003c\/li\u003e\n  \u003cli\u003eHow a Schmitt trigger cleans up fast pulses for reliable edge detection\u003c\/li\u003e\n  \u003cli\u003eVelocity factor of coaxial cables and its effect on signal propagation\u003c\/li\u003e\n  \u003cli\u003eBuilding a practical test instrument from discrete components\u003c\/li\u003e\n\u003c\/ul\u003e\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\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e74HC14 Schmidt\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e0.96in OLED\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e100nF Capacitor\u003c\/td\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e10kΩ Resistor\u003c\/td\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCoaxial Cable 3m\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e400-pt Breadboard\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM-M Wires (20-pack)\u003c\/td\u003e\n\u003ctd\u003e1\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\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\u003ch2\u003eWho This Kit Is For\u003c\/h2\u003e\n\u003cp\u003eThis kit is ideal for CBSE Class 11‑12 students learning wave propagation and reflection hands‑on. B.Tech ECE\/EEE undergraduates can use it for mini‑projects or Smart India Hackathon instrumentation challenges. ATL Tinkering Labs and college makerspaces (IIT, NIT, VIT, BITS) will value it as a reliable cable‑length estimator for tech fests and lab setups.\u003c\/p\u003e\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\u003cdetails\u003e\u003csummary\u003eWhat if I get stuck during the build?\u003c\/summary\u003e\u003cp\u003eScan the QR code to chat with the AI companion, or send a WhatsApp message for human backup. Both cover every step from component placement to Arduino code upload.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow accurate is the cable length measurement?\u003c\/summary\u003e\u003cp\u003eWith careful calibration using the included 3m coaxial cable, the TDR typically estimates within 5–10% of the true length. Accuracy depends on the known velocity factor and clean pulse edges.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan I measure cables other than coaxial?\u003c\/summary\u003e\u003cp\u003eYes, if you know the cable’s velocity factor. The Arduino code can be tweaked to accept a custom VF value, making it usable for twisted-pair or other transmission lines.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDo I need extra tools or instruments?\u003c\/summary\u003e\u003cp\u003eNothing beyond a computer to upload the Arduino sketch. A 9V battery provides power; the breadboard and wires make assembly solderless.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdiv class=\"kit-description\"\u003e\n  \u003cp\u003ePulse sent down cable. Reflection time measured with input capture. Cable length estimated from velocity factor.\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\u003e74HC14 Schmidt\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/096in-oled-display-128x64-i2cspi-for-arduino-raspberry-pi\"\u003e0.96in OLED\u003c\/a\u003e\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 x5\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 x5\u003c\/li\u003e\n    \u003cli\u003eCoaxial Cable 3m\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 x20\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 Cable Length TDR Estimator Kit with Arduino Uno + LED?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The Cable Length TDR Estimator Kit with Arduino Uno + LED includes all components needed: Arduino Uno R3, 74HC14 Schmidt, 0.96in OLED, 100nF Caps, 10kΩ Resistors 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 Cable Length TDR Estimator Kit with Arduino Uno + LED?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This kit is designed for Beginner level makers, suitable for ages 15-18. Pulse sent down cable. Reflection time measured with input capture. Cable length estimated from velocity factor. Estimated build time is 3-4 hrs.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I buy the Cable Length TDR Estimator Kit with Arduino Uno + LED online in India?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, the Cable Length TDR Estimator Kit with Arduino Uno + LED is available online at Compoden (compoden.in), India's AI-powered electronics and robotics store. 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