KY-040 Incremental Rotary Encoder Module with Button for Arduino and Control Systems

The KY-040 incremental encoder module detects the direction and speed of shaft rotation and accurately counts steps. Unlimited 360° rotation: Unlike standard potentiometers, the encoder shaft rotates endlessly with no end stops. Built-in tactile button: Pressing the shaft closes the SW contact, so the module can select menu items without adding extra buttons. Easy integration: Pull-up resistors are soldered onto the board, and the convenient 5-pin connector lets you quickly wire the module to developer boards. Features Type — Incremental mechanical rotary encoder Pulses — 20 pulses per revolution (360°) Built-in button — Tactile button activated by pressing the shaft (SW) Rotation angle — 360° (endless rotation, no stops) Operating voltage — 3.3 V – 5.0 V DC Pull-up resistors — Built onto the board (10 kΩ) Shaft type — D-shaped shaft, 6 mm diameter Interface — Digital two-phase (CLK, DT) + button (SW) Board dimensions — ~26 × 19 mm