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.

Shelly’s Gen4 relays start at $18 and can automate anything that’s wired, from light switches and garage door openers to ...

High Density Multi-Channel Relay Modules April 28, 2015 Automation Systems Interconnect, Inc. (ASI) introduces of the highest density DIN rail mounted multi-channel relay line available.

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 ...