This project is designed for use with an Arduino Pro Micro and a 4x4 keypad matrix. The code enables the Arduino to read input from the keypad and emulate keyboard input, sending keystrokes to a ...

A keypad is one of the most commonly used input devices in microprocessor applications. In a standard keypad wired as an X-Y switch matrix, normally-open switches connect a row to a column when ...

The voltages and signal timings described below are dependent on the battery voltage and are probably also impacted by temperature. While the calculator runs on a 9 V battery, internally the logic ...