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4-Channel Relay Module (STM32)

by M5Stack

4-Relay Module is a 4-Channel Relay module compatible with M5Stack Core and Core2 series, with 4-channel mechanical relays (NO, COM).

It supports I2C protocol. Also, it can be set by jumper into active/passive modes. This relay module supports DC control only, and Maximum load 24W (DC 24V@1A). Suitable for small load circuit control.


  • Embedded with STM32F030F4:
    • I2C communication (Addr: 0x26)
  • Relay:
    • 4x relay module (COM, NO interface)
    • Maximum load 24W (DC 24V@1A)
  • Supports two operation modes (selected by jumper).
    • Active mode.
      • Power input connects with relay NO port, to supply load directly.****
    • Passive mode.
      • Power input not connects to the relay port. The user's circuit needs individual power supply.
  • Power input (Support DC input only).
  • DC 5-24V INPUT -> M5 BUS HPWR Bus (Controlled by jumper. When stacking with several different M5 modules, HPWR Bus can supply power to other modules that need 24V power, such as SERVO2 module, etc.)
  • Development platform: Arduino, UIFlow(coming soon)


  • 1x 4-Relay Module
  • 5x Wiring Terminal 2.54mm-2P (green)
  • 10x PIN Jumper
  • 1x Wiring Instructions


  • On/off control
  • Solenoid valve control
  • DC control load on/off


Specifications Parameters
Main Control Chip STM32F030F4
Communication interface I2C communication interface (addr: 0x26)
Support operating mode Active control / Passive control
Relay channels 4x(COM, NO interface)
Power input interface DC 5-24V
Load capacity 4 channels max. 24W (DC 24V@1A)
Relay terminal specifications 2.54-2P
Net Weight 37.2g
Gross Weight 37.6g
Product size 54.2 x 54.2 x 13.2mm
Package size 95 x 65 x 25mm

Pin Mapping

4Relay Module SCL SDA 5V GND

Arduino examples