incremental rotary encoder 600 p/r LPD3806

Description

An Incremental Rotary Encoder (600 P/R) is a high-precision electromechanical sensor that measures the angular rotation of its shaft and converts it into digital electrical pulses. A common hobbyist and light-industrial model in this category is the LPD3806-600BM series.

Product Description

• Core Function: As the shaft rotates, the internal optical disk interrupts a light beam, generating square wave pulses on two separate output channels (Phase A and Phase B).

• 600 Pulses Per Revolution (P/R): This means the encoder outputs 600 distinct pulses for every full 360-degree rotation. By reading both rising and falling edges of Phase A and Phase B (quadrature decoding), your STM32 can achieve an effective resolution of 2,400 counts per revolution, offering exceptional precision for speed and position tracking.

• Direction Tracking: Because Phase A and Phase B are offset by 90 degrees (quadrature), the microcontroller can determine the direction of rotation (clockwise vs. counter-clockwise) by checking which phase goes high first.

Key Specifications

• Operating Voltage: Typically 5V to 24V DC.

• Output Type: Often NPN Open-Collector. (Note: This is highly advantageous for 3.3V systems. You can power the encoder with 5V, but connect the Phase A and B pull-up resistors to your STM32’s 3.3V rail, making the signal perfectly safe for the microcontroller).

• Maximum Mechanical Speed: Usually rated for up to 5000 RPM or 6000 RPM.

• Shaft Size: Standard 6mm solid stainless steel shaft, easily compatible with flexible aluminum couplings.

Price Range & Visual Reference

• Price in India: Typically ranges between at major robotics suppliers (such as Robu, Robocraze, or Quartz Components).

• Visual Identification: Look for a sturdy cylindrical aluminum body (usually black and silver) with a 6mm protruding shaft and a thick 4-wire cable exiting from the side or back.

Usage Tips for STM32

• Wiring: Standard wire colors are typically: Red (VCC), Black (GND), Green/White (Phase A), and White/Yellow (Phase B). Always check the specific datasheet or sticker on the motor.

• Hardware Timers: The STM32 has built-in Hardware Encoder Interface modes on its Advanced and General-Purpose Timers. Instead of using interrupt-heavy code to count the 2,400 ticks per revolution, you can configure an STM32 timer to handle quadrature decoding automatically in the background with zero CPU overhead!

• Pull-up Resistors: If your encoder is an NPN Open-Collector type, you must enable the internal pull-up resistors on your STM32 GPIO pins, or add external 10kΩ resistors pulled up to 3.3V.