Unit 4Relay
SKU:U097
Description
Unit 4Relay is a high-voltage drive unit that integrates 4-channel relay control. It is based on the STM32F030F4P6 microcontroller and uses the I2C bus to independently control four mechanical relays, supporting high-voltage switching of AC 250V / DC 28V. The unit communicates via a Grove HY2.0-4P interface and features physical isolation, programmable status indicator LEDs, and overload capability. It also adopts a LEGO-compatible mounting hole design, making it easy to integrate with LEGO structures or secure using screws. This unit is suitable for high-voltage load switching scenarios such as smart home applications, industrial control, and power management of high-power equipment.
Features
- Channel Count: 4-channel independent relay control
- Load Capacity: AC 250V@10A or DC 28V@10A
- Status Indication: Independent programmable LED indicator for each channel
- Isolation Feature: Physical isolation between high-voltage and low-voltage sides
- 2 x LEGO-compatible mounting holes
- Development Platform
- UiFlow1
- UiFlow2
- Arduino IDE
Includes
- 1 x Unit 4Relay
- 1 x HY2.0-4P Grove connection cable (20cm)
- 4 x HT3.96-4P terminals
Applications
- DC signal switching
- Power on/off for digital devices
Specifications
| Specification | Parameter |
|---|---|
| MCU | STM32F030F4P6 |
| Max Input Voltage | AC 250V / DC 28V |
| Rated Current | 10A |
| Max Instantaneous Current | 16A |
| Communication Interface | I2C @0x26 |
| Product Size | 112.0 x 23.0 x 18.0mm |
| Product Weight | 40.0g |
| Package Size | 163.0 x 100.0 x 20.0mm |
| Gross Weight | 84.0g |
Schematics
1/1
PinMap
Unit 4Relay
| HY2.0-4P | Black | Red | Yellow | White |
|---|---|---|---|---|
| PORT.A | GND | 5V | SDA | SCL |
Model Size
Structure
Softwares
Arduino
- Unit 4Relay Example with M5Atom
- Unit 4Relay Example with M5Core
- Unit 4Relay Example with M5Core2
- Unit 4Relay Example with M5StickC
- Unit 4Relay Example with M5StickC-Plus
UiFlow1
UiFlow2
Home Assistant
Protocol
- Protocol Type: I2C
- I2C Address: 0x26
Mode control Reg 0x10
| Bit | Desc | R/W |
|---|---|---|
| 7 | R | R/W |
| 6 | R | R/W |
| 5 | R | R/W |
| 4 | R | R/W |
| 3 | R | R/W |
| 2 | R | R/W |
| 1 | R | R/W |
| 0 | LED Sync Mode 0:Manual 1:Auto | R/W |
Working Mode Explanation
Manual: LED lights support independent control
Auto: LED follows Relay status changes, lights up when Relay is ON, turns off when OFF.
Auto: LED follows Relay status changes, lights up when Relay is ON, turns off when OFF.
RELAY control Reg 0x11
| Bit | Desc | R/W |
|---|---|---|
| 7 | LED1 / 1: ON 0:OFF | R/W |
| 6 | LED2 / 1: ON 0:OFF | R/W |
| 5 | LED3 / 1: ON 0:OFF | R/W |
| 4 | LED4 / 1: ON 0:OFF | R/W |
| 3 | RELAY1 / 1: ON 0:OFF | R/W |
| 2 | RELAY2 / 1: ON 0:OFF | R/W |
| 1 | RELAY3 / 1: ON 0:OFF | R/W |
| 0 | RELAY4 / 1: ON 0:OFF | R/W |
EasyLoader
| Easyloader | Download Link | Remarks |
|---|---|---|
| Unit 4Relay Example with M5Core | download | A key switches relay number, B key switches LED sync/async, C key controls all relays |
Video
- Unit 4Relay Test with M5Core
- UiFlow2 Unit 4Relay