Signal Input/Output
Arduino library for 4x4 (or smaller) keypad connected to an I2C PCF8574.
4x4, 5x3, 6x2, 8x1 or smaller.
Maintainer: Rob Tillaart
This library is compatible with all architectures so you should be able to use it on all the Arduino boards.
To use this library, open the Library Manager in the Arduino IDE and install it from there.