M5Stack 3A Relay Unit

The M5Stack 3A Relay Unit uses a relay to switch loads up to 30 V via a Grove port of an M5Stack Core, M5Stick or ATOM. The relay has a changeover contact with COM, NO and NC, and the load is connected to the header with 3.96 mm pitch. A transistor on the unit drives the relay coil, the 5 V for it come via the Grove cable.

Important: For safety reasons, the unit is only intended for voltages up to 30 V and not for mains voltage. The rating AC 220 V / 3 A given by M5Stack applies to the relay, not to the unit. The unit is therefore not suitable for switching the mains supply of devices such as a 3D printer.

Recommended alternative with more channels: M5Stack 4-Channel Relay Unit

Recommended Accessories:

• M5Stack Grove2Dupont Conversion Cable 20cm 10pcs

Features:

• 1 relay with changeover contact (COM, NO, NC)
• High-level control: the relay switches when the signal is HIGH
• Coil driven via a transistor, a 3.3 V signal is sufficient
• Load connection on a header with 3.96 mm pitch
• 2 mounting holes for snap pins or screws

Application Examples:

• Switching 12 V solenoid valves
• Switching LED strips with extra-low voltage on and off
• Controlling fans and pumps with extra-low voltage

Connection to M5Stack (3.3 V logic):

• Plug the Grove cable into port B of the Core; on the M5Core Basic the signal is on G26
• The unit takes the 5 V for the coil via the Grove cable
• GPIO HIGH: relay on, NO connected to COM. GPIO LOW: relay off, NC connected to COM

Connection to 5 V logic (for example Arduino UNO):

• With a Grove2Dupont cable: black to GND, red to 5V
• Yellow (DIN) to a digital output, for example pin 8, white remains free
• Output HIGH: relay on. Output LOW: relay off

Documentation:

• Unit Relay product page M5Stack
• Unit Relay with Arduino tutorial (M5Stack)
• M5Stack example code Arduino (GitHub)
• M5Stack example code UIFlow (GitHub)

Technical Data:

• Relay: HK4100F-DC5V-SHG
• Permissible voltage on this unit: up to 30 V
• Relay rating according to M5Stack: AC 220 V / 3 A, DC 30 V / 3 A
• Coil: 5 V, approx. 40 mA
• Control: HIGH = relay on
• Interface: Grove HY2.0-4P, pinout GND, 5V, DIN, NC
• Pin used: G26 (port B on the M5Core Basic)
• Load connection: COM, NO, NC, 3.96 mm pitch
• Mounting: 2 holes for snap pins or screws
• Dimensions: 48 × 24 × 14.6 mm
• Weight: 26 g

Scope of Delivery:

• 1× M5Stack 3A Relay Unit
• 1× Grove cable 20 cm
• 1× storage box