4 Channel Relay Board for ESP32 30-Pin, 5V Control
4 Channel Relay Board for ESP32 30-Pin (5V, Optocoupler Isolation)
The 4 Channel Relay Board is a dedicated expansion for ESP32 30-pin development boards, enabling control of high‑voltage AC or DC loads from 3.3V logic signals. Each of the four electromechanical relays is driven through an optocoupler, providing galvanic isolation between the microcontroller and the switching circuit. The board handles up to 10A per channel, making it suitable for home automation, industrial control, and IoT prototypes.
Key Specifications
| Specification | Value |
|---|---|
| Number of channels | 4 |
| Relay type | SRD-05VDC (or equivalent) |
| Coil voltage | 5 V DC |
| Max switching capacity | 10 A @ 250 V AC / 10 A @ 30 V DC |
| Input signal | Low‑level trigger (active LOW), 3.3‑5 V compatible |
| Isolation | Optocoupler isolation per channel |
| Compatible boards | ESP32 DevKit 30‑pin (fits directly); any 3.3‑5 V MCU with jumper wires |
| Dimensions | Approx. 70 mm × 55 mm × 20 mm |
What You Can Build With This
- Home automation system to control lights, fans, or appliances via Wi‑Fi using an ESP32.
- IoT‑enabled power outlet that toggles high‑power devices remotely from a smartphone.
- Motor or pump controller for aquaponics, irrigation, or small CNC machines.
- Smart greenhouse with timer‑based switching of heaters, humidifiers, or grow lights.
Compatibility
This board is designed to stack directly onto ESP32 development boards with 30 pins (the standard ESP32 DevKit V1 form factor). The relay inputs accept 3.3 V logic from the ESP32 GPIOs, and the board uses a separate 5 V supply for the relay coils—typically derived from the ESP32’s VIN pin when powered via USB, or an external 5 V source. It can also interface with Arduino, Raspberry Pi, or other microcontrollers using jumper wires, thanks to the low‑level trigger and optocoupler protection.
Wiring Notes
Connect VCC to a 5 V power source and GND to common ground. The IN1–IN4 pins go directly to any available ESP32 GPIOs. Because the relays are active LOW, setting a GPIO LOW energises the relay; HIGH turns it off. If your ESP32 board provides a 5 V output on the VIN pin, you can power the relay coils from there—just ensure the total current does not exceed the USB port limit. For high‑current applications, use an external 5 V supply and verify the jumper position on the JD‑VCC pin block.
Why Buy from Compoden
Every component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.
Is this compatible with ESP32 30‑pin boards?
Yes, this relay board is specifically designed for the 30‑pin ESP32 DevKit form factor. It aligns with the board’s pin headers and receives 3.3 V signals directly from the GPIOs.
What is the maximum current and voltage per relay?
Each relay can switch up to 10 A at 250 V AC or 10 A at 30 V DC. Always check the load rating and use appropriate fusing for safety.
Do I need a separate power supply for the relays?
In most cases, you can power the relay coils from the ESP32’s 5 V VIN pin when the board is powered via USB. For heavier loads, an external 5 V supply is recommended to avoid overloading the USB port.
📦 Free Setup Handoff Document Included
Every Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.
Ask Soldr above what you can build with this — it knows every Compoden kit this part appears in.
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items