A board enables wireless control, multi-channel switching, and isolation, supporting automation in homes, industrial systems, and connected applications.
Rajguru Electronics has introduced an ADIY 4-channel IoT relay board designed for wireless control and automation applications in smart homes, industrial systems, and IoT devices. The board is built around the ESP32-WROOM-32 module, combining Wi-Fi and Bluetooth connectivity with onboard relay switching and expansion options for custom integrations.
The compact unit measures approximately 85 mm × 54 mm and is designed for enclosure-based installations. It integrates four onboard electromechanical relays (QY46F/HF46F-G series) with opto-isolated driving, allowing electrical separation between low-voltage control circuitry and high-voltage loads. Each relay supports independent switching with a contact rating of up to 5A at 250 VAC (resistive load).
A key feature of the board is its isolation architecture, which includes optocouplers, PCB slot-based isolation, and reinforced insulation between coil and contact paths rated up to 4000 VAC. This design is intended to reduce electrical noise, improve safety, and extend operational life compared to conventional mechanical relay modules.
The ESP32 core enables wireless control through Wi-Fi (802.11 b/g/n) and Bluetooth 4.2/BLE, supporting standard IoT communication protocols such as MQTT, HTTP, HTTPS, TCP/UDP, WebSocket, SSL/TLS, and OTA updates. The board also includes a CH340G USB-to-UART interface for programming and debugging via USB Type-C.
For expansion, the board provides a 16-pin GPIO breakout along with a dedicated I2C header, enabling connection of external sensors, switches, and displays. Exposed GPIOs include multiple analog and digital pins such as IO32, IO33, IO26, IO27, IO34–IO39, and others, allowing flexible system design for embedded applications.
Power input support ranges from 3.3V to 5V, with onboard regulation using an AMS1117-3.3 LDO regulator. The board is designed for low-power IoT deployments while supporting high-current relay switching on external loads.
The company claims the module is designed for use in smart home automation systems, industrial control setups, remote monitoring solutions, and POS system integrations. It is intended for applications such as wireless control of lighting, appliances, machinery, and remote switching systems across networked environments.
With its combination of ESP32 wireless capability, multi-channel relay switching, and high isolation design, the board is targeted at developers and system integrators building compact IoT control systems.
