4x SPDT - IoTextra Relay2
4-channel SPDT relay module · 250 VAC / 30 VDC · 10 A · GPIO and/or I²C modes
Relay options: Panasonic ALQ105 · Omron G5Q-14 · HF33F/005-ZS3 · TE PE014005 · HOST and Qwiic connectors
Works with Raspberry Pi, Raspberry Pi Pico / Pico 2 (RP2040 / RP2350) and ESP32
DIN-rail mounting: A 3D-printable DIN-rail mounting tray is available — view on Printables
Part of the IoTextra series · compatible with IoTsmart and IoTbase · Open Hardware
This module is a member of the IoTextra series, which serves as a fundamental building block of our ecosystem and embodies the Make Things Happy Philosophy. It is engineered to bridge the gap between rapid prototyping and industrial-grade reliability.
Hardware Synergy: The module is compatible with both IoTsmart and IoTbase series.
Note: Usage with IoTbase or horizontal-mounted IoTsmart versions (V-HOST connector) requires a Height Extender or a dedicated riser adapter.
Software Power: This hardware compatibility unlocks the full potential of the IoTflow platform. It enables you to:
- Create custom Node-RED nodes effortlessly.
- Integrate via MQTT with third-party global platforms like Blynk.
- Scale your project from a single node to a complex industrial network.
Key Specifications
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Relay type: SPDT (1 Form C), choice of Panasonic ALQ105, Omron G5Q-14, HF33F/005-ZS3, or TE PE014005
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Switching rating: 250VAC / 30VDC, up to 10A
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Isolation: 4000Vrms coil-to-contact (1 min), 750Vrms across open contacts (1 min), 8000V surge resistance
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GPIO Mode: relay states controlled via AP0–AP3 signals on the HOST-P connector
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I²C Mode: relay states controlled via I²C using the onboard I/O expander (TCA9534 or compatible); up to 16 modules on one bus
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Hybrid control: some channels via HOST-P GPIO, others via the I²C expander, simultaneously
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Connectors: HOST-P10 or HOST-P12, Qwiic × 2
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Status indication: per-relay status LEDs
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Compatibility: Raspberry Pi, Raspberry Pi Pico, Arduino Nano, Nucleo, Adafruit, Teensy, ESP32, SeeedStudio XIAO, and others
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Size: 47 × 56 mm, with mounting holes for base-module or Raspberry Pi installation
Operation Modes
🔌 Standalone
Relay control is available through the HOST connector, or via the I²C bus using the onboard I/O expander.
🧠 Smart
An IoTsmart module is inserted into the HOST connector. Relay control and the 5V module supply are provided through HOST, powered from the IoTsmart module.
🏗 Mezzanine
The module is installed into an IoTbase carrier board. Relay control and the 5V module supply are provided through HOST.
Applications
🏭 IIoT / Industrial Automation
Contactors, signal lamps, sirens, auxiliary circuits — 4 isolated channels, up to 10A at 250VAC/30VDC.
🏢 Building Automation / HVAC
Fans, circulation pumps, ventilation solenoid valves — SPDT gives make and break from one relay.
💡 Lighting & Smart Home
Lighting circuits, outlets, small household loads — 4000Vrms coil-to-contact isolation.
⚙️ DC Motor Control & Power Switching
DC motors, solenoids, water/fuel pumps — up to 30VDC, 10A.
