High Speed Optical Tachometer Kit with Arduino Uno + LED
Advanced Optical Tachometer Kit – Precision RPM Measurement with Arduino Uno and OLED Readout
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
When you're optimizing motor control loops or characterizing a high-speed BLDC prototype, trusting an encoder just isn't enough—you need a non-contact reference that can keep up. This kit equips you to build a professional-grade optical tachometer capable of reading up to 100,000 RPM using a simple strobe principle and a clean analog front-end. The IR LED/photodiode pair captures rotor reflections, the LM393 comparator squares them into clean pulses, and the Arduino Uno counts them with 1-RPM resolution, all fed live to a crisp OLED display.
What You'll Build
You'll assemble and calibrate a full optical RPM instrument that attaches to any motor shaft with a piece of reflective tape. The OLED will show instantaneous RPM, maximum speed, and optionally a time-log via the DS3231 RTC. Every component—from the 940nm IR emitter to the BPW34 photodiode—is included, pre-matched for consistent signal amplitude. By the end, you'll have a bench-ready tool that outperforms many handheld tachometers, all built from first principles.
What You'll Learn
- Design an optical reflection sensor with IR LED, photodiode, and ambient light filtering
- Shape noisy photocurrent into TTL pulses using an LM393 comparator with hysteresis
- Implement an interrupt-driven RPM algorithm on Arduino Uno with overflow protection
- Interface an I2C OLED and RTC to add persistent logging and a user-friendly display
Kit Contents
| Component | Quantity |
|---|---|
| Arduino Uno R3 | 1 |
| IR LED 940nm | 2 |
| BPW34 Photodiode | 1 |
| LM393 Comparator | 1 |
| DS3231 RTC | 1 |
| 0.96in OLED | 1 |
| 220Ω Resistors | 5 |
| 10kΩ Resistors | 10 |
| 100nF Caps | 10 |
| PCB Prototype Board | 2 |
| 9V Battery Snap | 1 |
| Soldering Iron | 1 |
| Solder Wire | 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 advanced kit targets B.Tech ECE/EEE students working on motor drive characterization, Smart India Hackathon teams that need a reliable RPM readout, and IIT/NIT/VIT/BITS Pilani participants building FOC algorithms or high-speed spindle projects. CBSE Class 11-12 students comfortable with Arduino and basic analog electronics will also find it challenging, but the AI companion walks through every calculation. ATL Tinkering Lab mentors can use it as a capstone instrumentation project.
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?
Your QR code unlocks a companion that has seen this exact oscilloscope trace and knows every step. If you're still blocked, message us on WhatsApp and we'll help within hours.
Can I measure RPM without making physical contact with the motor?
Yes—stick a small piece of reflective tape on the rotating part. The IR beam bounces into the sensor, generating one pulse per revolution entirely without friction.
Will the readings stay accurate at low speeds, like 50 RPM?
At low RPM the Arduino's interrupt timing remains precise, but you'll need a clean reflection. We've included a 100nF capacitor filter to suppress spurious transitions at slow edges.
I have a 3D printer enclosure; can I mount the sensor remotely?
The BPW34 has a decent field of view. You can extend the LED and photodiode on wires from the comparator board, letting you position the head near a window in the enclosure.
IR LED and photodiode strobe measures RPM of spinning motors up to 100,000 RPM. OLED shows live speed.
What's in this kit
- Arduino Uno R3
- IR LED 940nm x2
- BPW34 Photodiode
- LM393 Comparator
- DS3231 RTC
- 0.96in OLED
- 220Ω Resistors x5
- 10kΩ Resistors x10
- 100nF Caps x10
- PCB Prototype Board x2
- 9V Battery Snap
- Soldering Iron
- Solder Wire
Choose your assembly option:
- Soldering Kit — 25W soldering iron, 60/40 solder wire, flux, and small perfboard for permanent assembly.
- Breadboard Combo — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.
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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