Oiyagai5-Pack Universal 4x4 Matrix Keypad Module with 16 Buttons, Ideal for Arduino DIY Projects

These are a little small but work great for breadboarding a project. All you need is a 9-line ribbon cable to connect this to a micro's inputs. Much easier than building a keypad on the breadboard!

Fast delivery and the switch matrix seems to be of excellent quality.

It's my own fault, but I failed to notice in the product description, just how tiny these little itty-bitty keypads are (4.3 cm x 3.8 cm). I am still going to keep them because I think I can still use them. In fact, my project enclosure box can be much smaller than I had planned, so there is a slim silver lining in this cloud. I just hope I can activate the keys without error because they are so close together for my old fat fingers. I guess I shall find out.Something else the product description pictures show (but, again, I did not notice): why are the header pins mounted on the wrong side of the board?? They are on the same side as the buttons, making it very difficult to mount the keypad on a PCB board, or plug into a breadboard; the buttons would be inaccessible if the existing header pins are mounted directly onto a PCB or breadboard! What was the manufacturer thinking? I can still use the keypads by removing the header pins and soldering on a new header on the correct (bottom) side of the board. But it begs the question as to why they are mounted on the wrong side to begin with.And another major problem (again, I failed to notice in the pictures): no mounting holes for stand-offs or for mounting in/on a project enclosure. So this makes it even more difficult to use these keypads in projects.

Alla knappar fungerar inte. Anslutninslisten sticker upp på samma sidan som knapparna sitter vilket känns fel. Jag har lött om dom så de sticker ner under istället. Har testat två knappsatsen och på den ena fungerade inte alls knappar.