Resources:
Documents
Compact 3 A SPDT Relay Unit With GPIO Control For AC And DC Load Switching
The M5Stack U023 Mini 3A Relay Unit is a compact single-channel relay module designed for switching electrical loads from a low-power GPIO control signal. It uses the HK4100F-DC5V-SHG electromechanical relay in an SPDT configuration and supports loads up to 220 V AC at 3 A or 30 V DC at 3 A. The relay provides COM, NO, and NC contacts, allowing the connected circuit to switch between normally-open and normally-closed states.
The module is controlled directly through a single GPIO signal and connects to compatible M5Stack controllers using the HY2.0-4P Grove interface. A built-in status indicator provides visual relay-state feedback, while physical isolation between the control and switched circuits helps separate the low-voltage controller from the load side. Two LEGO-compatible mounting holes support flexible mechanical installation in smart-home, automation, appliance-control, and embedded switching projects.
Key Features
- Single-Channel Relay: Uses 1 SPDT relay for switching between NO, NC, and COM contacts
- AC Load Capacity: Supports up to 220 V AC at 3 A
- DC Load Capacity: Supports up to 30 V DC at 3 A
- GPIO Control: Relay state is controlled directly using a single digital GPIO level
- 5 V Relay Coil: Relay channel operates from a 5 V supply with approximately 40 mA power consumption
- Fast Switching: Coil actuation time is approximately 6 ms with 4 ms release time
- Status Indicator: Integrated LED provides visual indication of relay operating state
- Grove Interface: HY2.0-4P connector simplifies integration with compatible M5Stack controllers
- Compact Size: Measures 48 x 24 x 8 mm for space-constrained automation projects
- Flexible Mounting: Includes 2 LEGO-compatible holes for screw or building-block installation
- Development Support: Compatible with UIFlow1, UIFlow2, and Arduino IDE
Applications
- Smart-home switching
- Appliance control
- Lighting control
- IoT relay systems
- Remote load switching
- Industrial automation prototypes
- Embedded control systems
- Electrical equipment switching
- DIY automation projects
- Smart-building control
- Low-voltage controller to high-voltage load interfacing
Model Size
Package Includes:
- 1 x Unit Relay
- 1 x HY2.0-4P Grove cable (20cm)
- 1 x 3.96 terminal
