However, if you use an LCD module with I2C interface, you only need 2 lines to process the display information. Now a days, it is not necessary to buy an expensive I2C LCD for this task because ...

If you’ve scavenged some random keypads and want to reuse them in a project without the hassle of figuring out the pinouts, then [Cliff Biffle] has an interface module for you. The Keypad Go … ...