๐ ๏ธ MAKER GUIDEJun 13, 2026โขโฑ๏ธ 1 min readโข๐ณ๐ต Tested in Nepal
Non-Contact Optical Motor Tachometer & RPM Meter with OLED Display
Measure rotational speeds of DC motors, fans, and pulleys with optical slotted optocoupler sensors and a 0.91" OLED display.
๐ ๏ธ BILL OF MATERIALS (BOM)
Required Hardware & Component Checklist
Curated components verified for this project. Check the items you need, adjust quantities, and add straight to cart:
Estimated Total (5/5 items):
NPRย 1,720
โ Cash on Delivery across Nepal
All parts selected
NPRย 750
NPRย 180
NPRย 500
NPRย 90
NPRย 200
Non-Contact Optical Motor Tachometer & RPM Meter with OLED Display
Read motor speeds up to 30,000 RPM using the Slotted Optocoupler Speed Sensor Module and hardware interrupts on an Arduino Nano.
Hardware Bill of Materials:
- Microcontroller: Arduino Nano V3.0 Solderless
- Optical Sensor: Speed Sensor Module Slotted Optocoupler Tachometer Counter LM393
- Display: 0.91 inch OLED module blue OLED 128X32 GND-VCC-SCL-SDA
- Power Management: Type C TP4056 Lithium Charger + 18650 3.7V 3000mAh Battery
Circuit Pinout & Wiring Connections:
| Sensor / Module Pin | Arduino Nano Pin | Function / Description |
|---|---|---|
| Slotted Optocoupler VCC / GND | 5V / GND | Sensor IR Beam Power |
| Slotted Optocoupler Digital OUT (DO) | Pin D2 (INT0) | Hardware Falling-Edge Pulse Interrupt |
| 0.91" OLED SDA / SCL | Pin A4 / Pin A5 | I2C Real-Time RPM Display |
โ Previous Guide
Multi-Zone Polyhouse Irrigation System with Capacitive Moisture & Solenoid Valves
Next Guide โ
Portable UV Radiation Index & Skin Protection Monitor with GUVA-S12SD
