{"product_id":"lm393-encoder-speed-sensor-module-for-rpm-measurement","title":"LM393 Encoder Speed Sensor Module for RPM Measurement","description":"\u003ch1\u003eLM393 Encoder Speed Sensor Module – Motor RPM Detection with Comparator\u003c\/h1\u003e\n\u003cp\u003eThe LM393 Encoder is an infrared speed sensor module built around the LM393 comparator. It uses an IR emitter and phototransistor pair, interrupted by a rotating slotted disc, to generate accurate digital pulses. The on‑board comparator cleans up the raw signal, providing a crisp falling edge on each slot transition. Whether you need to measure motor RPM, count rotations for a robot odometer, or build a custom tachometer, this module delivers reliable performance with minimal wiring.\u003c\/p\u003e\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOperating Voltage\u003c\/td\u003e\n\u003ctd\u003e3.3V – 5V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOutput Type\u003c\/td\u003e\n\u003ctd\u003eDigital TTL (Active Low)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eEncoder Wheel Slots\u003c\/td\u003e\n\u003ctd\u003e20 PPR (Pulses Per Revolution)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eModule Dimensions\u003c\/td\u003e\n\u003ctd\u003e32 × 14 mm (L × W)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eWheel Diameter\u003c\/td\u003e\n\u003ctd\u003e24 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOutput High Level\u003c\/td\u003e\n\u003ctd\u003eVCC (5V or 3.3V)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-dc-motor-speed-controller\"\u003eDigital tachometer to monitor motor speed in real time\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-line-following-robot\"\u003eLine‑following robot with closed‑loop speed feedback\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-wind-speed-anemometer\"\u003eDIY anemometer rotation counter for wind speed measurement\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003eRobot odometer to track distance travelled\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cp\u003eWorks seamlessly with any microcontroller that has a digital input pin. Ideal for Arduino Uno, Nano, Mega, ESP8266, ESP32, and Raspberry Pi (use a voltage divider if connecting directly to Pi GPIO). The module outputs a 0–VCC pulse train, compatible with both 3.3V and 5V logic levels.\u003c\/p\u003e\n\u003ch2\u003eWiring Notes\u003c\/h2\u003e\n\u003cp\u003eConnect VCC to 5V (or 3.3V), GND to ground, and OUT to any digital I\/O pin. The on‑board comparator provides a clean signal without the need for external pull‑up resistors. For noisy environments, solder a 0.1µF ceramic capacitor between VCC and GND near the module pins.\u003c\/p\u003e\n\u003ch2\u003eWhy Buy from Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.\u003c\/p\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this compatible with Arduino?\u003c\/summary\u003e\u003cp\u003eYes, it works with all 5V Arduino boards. Connect VCC to 5V, GND to GND, and OUT to any digital pin. Use Arduino’s pulseIn() or interrupts to count pulses.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow many pulses per revolution does the wheel provide?\u003c\/summary\u003e\u003cp\u003eThe included encoder wheel has 20 slots, so you get 20 pulses per full revolution. Multiply the measured frequency by 3 to get RPM.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan I use this sensor with a 3.3V system like ESP32?\u003c\/summary\u003e\u003cp\u003eAbsolutely. Power the module with 3.3V from the ESP32, and the output will swing between 0V and 3.3V, safe for its GPIO pins.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdiv class=\"compoden-handoff\" style=\"margin-top:24px;padding:16px;background:#f0f4ff;border-left:4px solid #2B4D8F;border-radius:4px;\"\u003e\n  \u003cp style=\"margin:0 0 6px 0;font-weight:600;color:#1A3560;\"\u003e📦 Free Setup Handoff Document Included\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-size:0.95em;color:#333;\"\u003eEvery Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53445076091245,"sku":"CDN-0913","price":95.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/image_1_1d0e4b81-192c-4695-923f-9ecb379156e0.jpg?v=1781513159","url":"https:\/\/compoden.com\/products\/lm393-encoder-speed-sensor-module-for-rpm-measurement","provider":"Compoden","version":"1.0","type":"link"}