Description Unit Relay is a single-channel relay control unit for high-voltage switching applications. It is based on the HK4100F-DC5V-SHG relay and provides SPDT (Single Pole Double Throw) switching, supporting load control up to AC 220V@3A or DC 30V@3A. The unit is directly driven by a single GPIO logic level and includes physical isolation plus a relay status indicator LED. It provides ON, OFF, and COM terminals, allowing the common terminal COM to connect to either ON or OFF through GPIO control. Features 1 x SPDT relay channel Based on HK4100F-DC5V-SHG relay Load capacity: AC 220V@3A or DC 30V@3A Direct single GPIO level drive Relay status indicator LED Physical isolation design Grove HY2.0-4P communication interface 2 x LEGO-compatible holes Development platforms: UiFlow1, UiFlow2, Arduino IDE Specifications Specification Parameter Relay Type 1 x SPDT Relay Relay Model HK4100F-DC5V-SHG Load Capacity AC 220V@3A or DC 30V@3A Control Method Direct single GPIO level drive Single Relay Power Consumption 5V@40mA Coil Action Time 6ms Coil Release Time 4ms Interface Grove HY2.0-4P Product Size 48.0 x 24.0 x 8.0mm Product Weight 9.5g Package Size 138.0 x 93.0 x 9.0mm Gross Weight 17.1g Interface Uses Grove HY2.0-4P interface Uses direct GPIO level control Relay terminals: ON, OFF, COM COM can be switched to ON or OFF through GPIO output control Applications Smart home power control Automation equipment switching Remote control of appliances such as refrigerators, air conditioners, and TVs Safety protection and circuit switching projects Product List 1 x Unit Relay 1 x HY2.0-4P Grove Cable (20cm) 1 x 3.96 Terminal Other Content Unit Relay works as an automatic switch that uses a low-current control signal to switch a higher-current circuit. It is suitable for power management and automation scenarios where GPIO-based relay switching is required. Resources Official Documentation Unit Relay Schematics PDF Unit Relay Structure Files Relay Datasheet Unit Relay Test Example with M5Atom Unit Relay Test Example with M5Core Unit Relay Test Example with M5Core2 Unit Relay Test Example with M5StickC Unit Relay Test Example with M5StickC-Plus UiFlow2 Documentation Unit Relay Test EasyLoader Official Product Video Relay Unit Application Video FAQ What relay model does Unit Relay use? It uses the HK4100F-DC5V-SHG relay. What load can it control? It supports up to AC 220V@3A or DC 30V@3A. How is the relay controlled? It is directly driven by a single GPIO logic level. What terminals does it provide? It provides ON, OFF, and COM terminals for relay switching. What is included in the package? The package includes 1 x Unit Relay, 1 x HY2.0-4P Grove cable, and 1 x 3.96 terminal.
