KY-040 Rotary Encoder Module with Integrated Push-Button

KY-040 Rotary Encoder Module is a versatile, 360-degree incremental input device that offers an intuitive way to manage digital systems through rotating and tactile feedback. Unlike standard potentiometers, this module can rotate indefinitely without a physical stop, providing pulses that a microcontroller uses to determine both the direction and magnitude of rotation. Furthermore, the integrated momentary push-button switch adds an extra layer of functionality, allowing users to select menu items or reset parameters with a single press. Consequently, it has become a staple in the hobbyist and industrial community for creating interactive user interfaces. Therefore, you can easily implement the KY-040 to replace multiple buttons or bulky switches in your next embedded project, ensuring a sleek and modern control scheme.

Key Features:

• 360-Degree Rotation: The encoder rotates continuously in either direction without any fixed limits, providing infinite positioning capability.
• Integrated Push-Button: A built-in tactile switch activates when the user presses the shaft, simplifying menu navigation and mode selection.
• Digital Output: It generates two-phase Gray code (A and B) outputs, which allow the host processor to accurately track rotation speed and direction.
• Breadboard Friendly: The module features standard 2.54 mm pin headers, enabling rapid prototyping on breadboards or easy connection via jumper wires.
• Internal Pull-up Resistors: Most versions of this module include surface-mount pull-up resistors for the CLK and DT lines, reducing the need for external components.

Technical Specifications:

• Operating Voltage: 3.3 V to 5 V DC
• Pulses Per Revolution (PPR): 20 Pulses
• Output Type: 2-bit Gray Code (Incremental)
• Switch Type: Momentary SPST Push-Button
• Mechanical Life: ≈ 30,000 cycles minimum
• Rotation Angle: 360° (Continuous)

Mechanical Specifications:

• Shaft Type: D-shape / Flatted Shaft (for secure knob mounting)
• Shaft Material: Aluminum or Plastic-Steel Alloy
• PCB Material: FR-4 Glass Epoxy
• Mounting Hole: Integrated nut and washer for panel mounting applications.

Dimensions:

• PCB Size: ≈ 32 mm x 19 mm
• Shaft Diameter: ≈ 6 mm
• Shaft Length: ≈ 15 mm to 20 mm (Total)
• Total Height: ≈ 30 mm (Including pins and shaft)

Pinout and Wiring:

• CLK (Clock): Primary output pulse to determine rotation. Connect to a digital input (interrupt-capable pins recommended).
• DT (Data): Secondary output pulse. However, the phase relationship between CLK and DT determines the direction (CW or CCW).
• SW (Switch): Output for the internal momentary push-button. It typically pulls to ground when pressed.
• + (VCC): Connect to the 3.3 V or 5 V power supply rail.
• GND: Connect to the common ground of the circuit.

Datasheet Reference:

• Download KY-040 Rotary Encoder Module Datasheet

Commonly Used in:

• 3D Printer Controllers: Navigating Marlin or RepRap menus on LCD screens like the RepRapDiscount Smart Controller.
• Audio Equipment: Managing digital volume controls, frequency tuning, and track selection in DIY media players.
• Industrial Panels: Setting threshold values or selecting operational modes in PLC-interfaced systems.

Applications:

• Menu Navigation: Scrolling through complex digital menus and confirming selections with the integrated button.
• Digital Potentiometer Replacement: Adjusting parameters like LED brightness or motor speed without being limited by physical stops.
• Robotic Control: Providing manual steering or precise joint adjustment during the testing phase of a robot.

Equivalent Models:

• PEC11R Series (Bourns): A high-quality standalone encoder that offers similar incremental output and push-switch options.
• EC11 Encoder: The underlying component used in the KY-040 module, often found without the breakout PCB.
• KY-040 (Modified): Some variants use different PCB layouts, however, the pin functions and signaling remains standard across the series.

Package Includes:

• 1 x KY-040 Rotary Encoder Module with Integrated Push-Button