The PiRelay is a Raspberry Pi relay HAT that lets you control high-current and high-voltage devices directly from your Pi. Transform your home appliances into smart IoT devices with four independent relay channels capable of switching loads up to 240VAC/7A or 125VDC/10A.

The standardised HAT form factor connects smoothly to any 40-pin Raspberry Pi, with a stacking header that keeps GPIO pins accessible for additional boards. LED indicators show relay status at a glance for easy debugging.

Key Features

• 4 Independent Relays – Control up to four appliances simultaneously
• High Power Switching – Handles 240VAC/7A or 125VDC/10A per relay
• Status LEDs – Visual indicator for each relay state
• Stacking Header – 40-pin passthrough keeps GPIO accessible
• Flexible Wiring – COM, NO (Normally Open), and NC (Normally Closed) terminals per relay
• Configurable GPIO – Remove jumpers to use custom GPIO pins
• Mobile App Control – PiRelay Android app available

Specifications

• Relay Rating: 240VAC/7A, 125VDC/10A
• Number of Relays: 4
• Default GPIO Pins: GPIO 4, 17, 27, 22
• Compatibility: Raspberry Pi 4, 3B+, 3, 2, Zero (all 40-pin models)

GPIO Pin Mapping

• Pin 2: 5V Power
• Pin 6: GND
• Pin 7 (GPIO 4): Relay 4
• Pin 11 (GPIO 17): Relay 3
• Pin 13 (GPIO 27): Relay 2
• Pin 15 (GPIO 22): Relay 1

Ideal For

• Home automation and IoT projects
• Controlling lights, fans, and appliances
• Industrial control applications
• Switching high-power loads from Raspberry Pi

Package Contents

• 1× PiRelay HAT
• 2× Standoffs

Resources

• Getting Started Guide
• Example Code and Python Library