GPIO and/or I²C modes · HOST and Qwiic connectors · 47×56 mm · 5 VDC supply
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.
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
Relay type: SPST-NO (1 Form A) solid-state relay
On-resistance: from 0.05Ω, depending on the SSR model and load
Isolation: individual galvanic isolation per channel, 5000Vrms insulation voltage
GPIO Mode: SSR states controlled directly via AP0–AP7 signals on the HOST-P connector
I²C Mode: SSR states controlled via I²C using the onboard I/O expander (TCA9534 or compatible); up to 16 modules on one bus
Hybrid control: some channels via HOST-P GPIO, others via the I²C expander, simultaneously
The maximum switching voltage and current depend on the specific SSR model installed:
Load voltage, V
Load current, A
On-resistance, Ω
60
0.5
2.5
40
2
0.1
30
4
0.05
350
0.12
30
Current If = 5mA, voltage Vf up to 1.5V.
Operation Modes
🔌 Standalone
SSR control is available through the HOST connector, or via the I²C bus using the onboard I/O expander.
🧠 Smart
An IoTsmart module is inserted vertically into the HOST connector. SSR 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. SSR control and the 5V module supply are provided through HOST.
Applications
🏭IIoT / Industrial Automation Heating elements, solenoid valves, signal circuits — 8 independent channels, no moving contacts, essentially unlimited switching life.
🏢Building Automation / HVAC Ventilation fans, heating and cooling solenoid valves — silent switching, no audible click.
Aquarium & Reptile Care Aquarium heaters, UV/grow lamps, circulation pumps, and misting systems on AC and DC voltages — 5000Vrms isolation supports safe operation near water.
💡Lighting & Smart Home Dimmable and standard lighting control, outlets, small household loads — fast, spark-free switching.
