The input circuit is a simple keypad matrix. To read each button push, the Arduino brings one keypad input line high and checks the voltage of the four output lines in order. The diodes on the PC ...

The keypad uses an onboard ATMega328P to scan the matrix for button presses, decode them, and send them via UART or I²C to an Arduino. [ELECTRONOOBS] has the PCB files available via Patreon for ...

That requires users to intermittently push a button in order to produce additional ‘on’ time and has been aptly named the, “Unhackable Arduino Switch Matrix.” The ‘unhackable’ switch ...

The $87.36 Arduino Plug and Make Kit comes with an Arduino UNO R4 WiFi microcomputer featuring Bluetooth and its own built-in 12 x 8 LED matrix display ... and a set of three buttons.