360 Degree Rotary Encoder Module with Push Button

Overview

The 360 Degree Rotary Encoder Module is the ultimate input device for modern DIY electronics. While a potentiometer only measures a fixed range of resistance, this incremental encoder outputs a digital pulse every time it rotates, allowing for infinite turning in either direction.

Because it tracks both the amount of rotation and the direction, it is incredibly useful for navigating LCD menus, adjusting the volume on digital amplifiers, or jogging stepper motors on custom CNC builds. Pressing down on the knob triggers the built-in switch, allowing you to use it as an "Enter" or "Select" button.

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Technical Specifications

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Pinout Configuration

The module features a straightforward 5-pin layout:

• VCC (+): Power Supply (3.3V or 5V)
• GND: Ground
• CLK (A): Primary output pulse (Clock)
• DT (B): Secondary output pulse (Data) - used to determine direction
• SW: Digital output for the push button (Active LOW when pressed)

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How It Works

Inside the encoder, a rotating disc alternately connects the CLK and DT pins to ground, producing square waves. Because these two pins are physically offset, their signals are 90 degrees out of phase (quadrature).

Your microcontroller determines the direction of rotation by looking at which pin changes state first:

• Clockwise: CLK goes LOW first, then DT goes LOW.
• Counter-Clockwise: DT goes LOW first, then CLK goes LOW.

💡 Code Tip: For the most reliable performance and to prevent "missed steps" when turning the knob quickly, always use Hardware Interrupts in your code rather than basic polling methods.