Quick Take
For a machine-safety or HMI panel, the encoder choice often comes down to how much wiring you want to do. A bare EC11 with a D shaft and push switch is the direct route for PCB mounting. The KY-040 module is the easiest for Arduino and Raspberry Pi breadboard projects because the pull-up resistors are already on the board. The two Alps 2-packs give you 30-detent rotation, a momentary press switch, and PC board mounting in a component format. Listed prices run from USD 2.50 to USD 9.95, so you can choose based on packaging and interface rather than a large budget commitment.
Listed Price Comparison
| Product | Listed Price | Price Bar |
|---|---|---|
| 2 X Alps Rotary Encoder w/ Momentary Switch - 30 Detent / 360 Degrees - PC Board | USD 9.95 | |
| Alps Rotary Encoder Momentary Switch 30 Detents 360 Degrees 2 Pack | USD 6.50 | |
| 2X KY-040 Rotary Encoder Module with Pushbutton Switch for Arduino Raspberry Pi | USD 7.69 | |
| 1 Pc - EC11 360 Degree Rotary Encoder PCB Mount Push Switch D Shaft | USD 2.50 |
Decision Matrix
| Product | Pick it for | Watch out for |
|---|---|---|
| Alps 2-Pack with Momentary Switch (PC Board) | PCB-mounted projects where you want two encoders with PC pin leads | You will wire the bare leads yourself |
| Alps 2-Pack (Japan) | Front-panel or upright builds that need vertical orientation | It is a component, not a breakout module |
| KY-040 Module 2-Pack | Arduino and Raspberry Pi breadboard input with pull-up resistors onboard | Standard module footprint with pin interface |
| EC11 PCB Mount Encoder | A single through-hole encoder with D shaft and push switch | Switch contacts are rated for 5V @ 10mA signal-level use |
Product Notes
2 X Alps Rotary Encoder with Momentary Switch (PC Board)
Need two Alps encoders with a press-to-select feel? The 2 X Alps Rotary Encoder with Momentary Switch is packaged for PC board mounting and includes PC pin termination. The description lists a 360-degree endless shaft with 30 detent points and a momentary push switch, so you can rotate continuously and still click to confirm a menu item. The switch action is momentary, which means it returns after you release it; that's ideal for temporary selections rather than latching settings. You are getting two components in one listing, which makes it easy to keep a spare or build a two-channel control.
Alps Rotary Encoder 2-Pack (Japan)
This Alps Rotary Encoder 2-Pack is listed with the same 30 detents, 360-degree movement, and momentary switch as the other Alps pair, but its attributes add Japan origin, 2-phase output, and vertical orientation. If you need the encoder to mount upright on a board and report direction with quadrature-style signals, the 2-phase detail is useful. The momentary operation method is on/off, so pressing the shaft gives you a non-latching select signal. It's a component with PC board mount leads and support tabs, so you'll be soldering it into your own layout rather than plugging it into a breadboard.
KY-040 Rotary Encoder Module 2-Pack
The KY-040 Rotary Encoder Module 2-Pack is the only option here that arrives as a module with onboard 10kΩ pull-up resistors. That removes a common wiring step for Arduino and Raspberry Pi projects. The listing describes digital quadrature outputs, continuous 360-degree rotation, 20 detents per revolution, and a built-in pushbutton switch. The two modules are compatible with 5V and 3.3V systems, which suits both 5V Arduinos and 3.3V Raspberry Pi GPIO. The module has a standard pin interface, so the pushbutton and quadrature outputs are the main features rather than an exposed shaft.
EC11 360 Degree Rotary Encoder PCB Mount Push Switch D Shaft
The EC11 360 Degree Rotary Encoder PCB Mount Push Switch D Shaft gives you a single through-hole component with a D-shaped shaft, 15 mm shaft length, and seven pins for PCB mounting. The description lists a push-to-actuate momentary switch and directional mechanical switching that provides 20 pulses per revolution. The switch contacts are rated at 5 volts and 10 mA, so you can plan signal-level switching rather than power loads. Because it is a single encoder sold on its own, it fits when you only need one channel for a prototype or a repair. It is a bare-bones option in this group and requires your own mounting and wiring approach.
Final Recommendation
For a panel build where you want two identical Alps encoders with a momentary push switch, the 2 X Alps Rotary Encoder with Momentary Switch (PC Board) covers the PC board mounting and PC pin termination in one listing. If you prefer an Alps 2-pack with Japan origin and vertical orientation, the other Alps 2-pack is the matching alternative. For a breadboard-friendly input block on Arduino or Raspberry Pi, go with the KY-040 module. For a solo through-hole EC11 with D shaft and push switch, the EC11 listing is the direct route.
