iot & smart home
Tiny Contacts Fits Four Relays Onto a 42 x 38 mm ESP32 Board
Four Omron surface-mount relays on a 42 x 38 mm board, driven by a ULN2003A so your ESP32 GPIO pins never touch a relay…
uncategorized
Build an ESP32 Water Tank Controller With an Ultrasonic Sensor
An ESP32, an ultrasonic sensor, and a relay turn a manual rooftop water pump into a hands-off system that fills the tank and stops…
microcontrollers
Olimex PICO-EVB Turns a Raspberry Pi Pico Into a Mini-PLC
Olimex PICO-EVB turns a Raspberry Pi Pico into a real PLC: four 15A relays, optoisolated inputs, and Home Assistant support for about $17.