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 ...

The RFID reader communicates with the Arduino through the SPI protocol and different Arduino boards have different SPI pins. To test if the RFID reader is working properly or not, upload the “dumpinfo ...

If you want to add a keypad to your Arduino project, the options are pretty limited. There’s that red and blue 4×4 membrane we’ve all seen in password-protected door lock projects, and the phone ...