By connecting multiple MFRC522 RFID readers to an Arduino Uno, ... as a quick demonstration of how both the RFID “combination” and manual override can be used to trigger the attached relay.

The Silicon Labs Si4735 is a single-chip solution for receiving AM, FM, and shortwave radio. With a bit of hacking, it even supports single sideband (SSB). All you’ve got to do is provide it … ...

PYGO boards are also stackable on top of each other on the same Arduino board and have built-in measurement redundancies. The level shifters for voltage are integrated to allow I2C sensors to work ...