Actually I already read this page several times and I still habe no idea where the problem is. But i could enclose the problem on the pin 2, Pin 15 is working. When I use GPIO 2 as Output, it works, but some keys shows the value of other keys, but when I use it as Input, nearly nothing works any mor...

Hey all, I am trying to use a 4x4 Matrix Keypad on my NodeMCU esp32 board following this tutorial: diyi0t.com I want to use the pins 15, 2, 4, 16, 17, 5, 18, 19 but I get weird results (three buttons hand back the value of other buttons). When I use the Pins 4, 16, 17, 5, 18, 19, 21, 3 (or other Pin...