KY-040 360 Degree Rotary Encoder Module

The 360 Degree Rotary Encoder Module (KY-040) is a versatile digital input device that lets you add smooth, precise knob control to your electronics projects. Unlike a standard potentiometer, this rotary encoder spins continuously in either direction with no start or end stop, making it perfect for menu navigation, volume control, digital potentiometers, motor speed adjustment, and any application needing unlimited rotational input. As you turn the knob, it outputs quadrature digital pulses on its CLK and DT pins, letting your microcontroller determine both the amount and direction of rotation with reliable accuracy.

Built into the module is a handy push-button switch, activated by pressing straight down on the shaft, giving you an extra input for confirming selections or toggling functions without adding separate components. With 20 tactile detents per full revolution, each rotation step gives a satisfying physical click, making fine adjustments easy and intuitive. The board includes onboard pull-up resistors on all signal lines, so it connects directly to your microcontroller with simple jumper wires, no external resistors needed. Compatible with Arduino, ESP32, ESP8266, Raspberry Pi, and most other 5V or 3.3V microcontroller platforms, this rotary encoder module is a popular choice for hobbyists building smart home controllers, audio equipment, instrumentation panels, and interactive user interfaces.

Specification:

• Model : KY-040
• Type : Incremental rotary encoder
• Rotation : Continuous 360°, unlimited
• Detents Per Revolution : 20
• Output Type : Quadrature digital (CLK, DT)
• Working Voltage : 0V to 5V
• Push Button : Integrated, normally open
• Pull-Up Resistors : Onboard, 10kΩ
• Pin Interface : CLK, DT, SW, +, GND
• Dimensions : Approx. 32 x 19 x 30mm