Relay Module Tutorials

Build an Arduino Nano EM4100 125 kHz RFID door lock with EEPROM multi-card access and a relay-driven electric strike ...

Build an Arduino YF-S201 water flow meter to measure liters per minute and total liters for dosing, monitoring, and l...

Build a high-current Arduino DC motor reverser using a 4-channel relay module with safe interlock wiring, ideal for a...

Build an AC 220V time delay relay mains timer with optional ESP8266 WiFi triggering for fans, pumps, and lights using...

Build an Arduino Nano USB ultrasonic mist maker diffuser with relay control, WS2812B lighting, and a soil sensor opti...

Build a hidden touch switch using an Arduino Nano and TTP223B to toggle a relay through acrylic or wood, for clean en...

Build an Arduino Nano motion detector using the RCWL-0516 microwave radar sensor to switch a relay, with reliable thr...

Build an ESP32 capacitive soil moisture smart plant monitor that waters only when dry, supports deep sleep battery li...

Compare relay modules, NPN transistors, and logic-level MOSFETs with Arduino Nano wiring examples so you choose the r...

Learn Arduino GPIO sinking vs sourcing current with simple LED wiring diagrams and safe current limits so you avoid b...

Build an Arduino Nano DS3231 sunrise alarm clock with an LED fade-in, relay control, and OLED display for a gentler w...

Build an Arduino Nano DS18B20 relay fermentation controller to hold stable yogurt or sourdough temperatures using an ...