For this, just wire up the hardware (arduino+keypad) as described earlier ... you have to fiddle the “rummy” keypad using your analog multimeter. It might take hours to get to work, be patient!

The four transistor select lines connect to Arduino pins 0, 1, 2, and 3. Yes, they’re marked Analog in, but it doesn’t matter. The keypad switch matrix is connected in four columns and two rows.

Watch the video below to learn more about his Arduino-based portable keypad that connects to your Arduino development board and offers the complete alphabet, numbers 0-9 as well as several commands.

An Arduino Pro Micro provides a USB interface to a PC and reads out the various input units. The entire design is modular, so it can be customized to any desired combination of analog and digital ...

developers and hobbyists looking for a fully featured Arduino Mega compatible PLC may be interested in a new Indiegogo campaign launched today for a new development board featuring 52 analog and ...