Cable Length TDR Estimator Kit with Arduino Uno + LED
Cable Length TDR Estimator Kit with Arduino Uno & OLED – Build a DIY Time Domain Reflectometer
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Ever 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.
What You'll Build
A 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.
What You'll Learn
- Precision timing with Arduino’s input capture unit
- How a Schmitt trigger cleans up fast pulses for reliable edge detection
- Velocity factor of coaxial cables and its effect on signal propagation
- Building a practical test instrument from discrete components
Kit Contents
| Component | Quantity |
|---|---|
| Arduino Uno R3 | 1 |
| 74HC14 Schmidt | 1 |
| 0.96in OLED | 1 |
| 100nF Capacitor | 5 |
| 10kΩ Resistor | 5 |
| Coaxial Cable 3m | 1 |
| 400-pt Breadboard | 1 |
| M-M Wires (20-pack) | 1 |
| 9V Battery Snap | 1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
This 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.
Built and Backed by Compoden
Every 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.
What if I get stuck during the build?
Scan 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.
How accurate is the cable length measurement?
With 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.
Can I measure cables other than coaxial?
Yes, 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.
Do I need extra tools or instruments?
Nothing beyond a computer to upload the Arduino sketch. A 9V battery provides power; the breadboard and wires make assembly solderless.
Pulse sent down cable. Reflection time measured with input capture. Cable length estimated from velocity factor.
What's in this kit
- Arduino Uno R3
- 74HC14 Schmidt
- 0.96in OLED
- 100nF Caps x5
- 10kΩ Resistors x5
- Coaxial Cable 3m
- 400-pt Breadboard
- M-M Wires x20
- 9V Battery Snap
Other projects you can build
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items