5Pcs KY-040 Rotary Encoder Module with 15×16.5 mm with Knob Cap for Arduino (Pack of 5) CYT1062

Very good product for the price point. Knobs are good quality and fit the encoder well. With the threaded shaft, the encoder has panel mount capabilities. All hardware was included and everything works fine. Soldering on the board is good, and I don't expect to have any issues with these. I have implemented 2 of these into my design with no issues. Plus I have 3 more for my next project.

Checked all 5 on the scope. They all worked reliably down to 1.2V. (The product description says 5V), my projects usually run at 3.3V or 2.2V for NiMH battery powered. There is no ringing or glitching on the Clock, Data, or Button Data signals. (No need to de-bounce or worry about false data). My Fluke couldn't read any idle current, so it is less than 10uA. All lines are normally high. Pressing the button does not change the Clock or Data lines. Data is valid on Falling or Rising edge of the clock. Although, the data line is stable for a longer period of time when using the falling edge of the clock. There is one clock pule per indent on the shaft. Turning Clock-Wise. and using the falling edge, data is high. Turning Counter Clock-Wise. and using the falling edge, data is low. (Data level is reversed if you are using the rising edge of the clock. So, this is perfect for any project running from 2.2V to 5V. I am exceptionally happy with this product!

I've been testing these now for a few days on my bench and they seem reliable. The action is smooth, with reasonably noticeable detent points. There are two steps per detent in the output. Markings on the pins are CLK, D0, SW, VCC, GND. CLK and D0 are the A and B pins. The switch is active low as delivered. The knob is ok, though it is only a press-fit. The pic is a little deceiving in that the end of the pot makes it look like a really high quality knob but the sides are the same plastic you get on most knobs. Taking one star for the knob quality.

nice encoders. They have the pull-up or down resistors on the board. The connector is a .1 inch (2.54mm) pitch so will fit cables or will plug into a socket on a PCB. They come with a knob and a knut for the encoder shaft. The knob has a flat on one side that matches the one on the shaft and fits tight. Ther is no grub screw or hole for one. I am not too sure how well that would last with heavy use, seems fragile to me. However, in my opinion, they are a very good value for the money. James Cullins

Was having hours of frustrations using analog potentiometers and other rotary encoder dials that were NOT soldered to a board like this one. Problems gone, results are spot-on accurate! Wish this was my first choice, would have saved dozens of hours.

These rotary encoders have a good quality feel to them, and work well. Pushing the knob gives a nice click, and it clicks as you rotate the knob.

I like that you can turn AND use them as buttons. EASY TO HOOK UP AND PROGRAM, especially with Arduino. Comments I've had from others, though, have been that the caps had a mark on them, but they are ROTARY ENCODERS - they continue to turn, so the mark on them starts to seem unneeded. If they were potentiometers with limits, it would make more sense. Because these don't stop, I had to program them to recognize when they hit the limit, even if it spins around multiple times.

Prior to ordering these I read plenty of information stating that they are prone to frequently generating backward or double inputs. I bought them anyway because of they are inexpensive. I test all five on an Arduino Uno as soon as I got them, and the results at that point were promising - no inaccurate inputs, felt good mechanically, and were working well with my project. Unfortunately, each of them were doing the inaccurate inputs within about 15 minutes of use. I had wondered if this might be related to what I had set up on the Arduino, so I removed everything else and ran a sketch that involved only the encoders. The inputs were just as unreliable. If you just need something to use for testing or development, and are okay with some backward and/or double inputs, then these will do the trick. Otherwise, go for a higher quality encoder. 17-Apr-2023 Update: Having spent some time working with these and finding that they were getting increasingly less reliable, I kept thinking to myself that they can't be THIS bad. After doing some searching and tinkering, I found a sketch that gets them working very well. Search the internet for the page titled "Rotary Encoder: Immediately Tame your Noisy Encoder" to see the explanation article which includes the code. I'm changing my product rating from two to three stars since the product works, but not very well right out of the package.