Eight-channel relay boards are common for automating lights, pumps, and other devices in DIY projects. This article reviews five popular 8-channel models, focusing on compatibility, isolation, and driving requirements. Each product is suitable for hobbyists and professionals using Arduino, Raspberry Pi, ESP32, and other microcontrollers. A quick buying guide follows to help you compare features such as voltage levels, isolation, and current handling.
| Product | Brand | Voltage | Channel Count | Isolation | Notes |
|---|---|---|---|---|---|
| SunFounder 5V 8-Channel Relay Shield | SunFounder | 5V | 8 | Direct drive | Widely compatible with microcontrollers |
| ELEGOO 8 Channel DC 5V Relay Module | ELEGOO | 5V | 8 | Optocoupler | With optocouplers for isolation |
| DEVMO 8 Channel DC 5V Relay Module Board | DEVMO | 5V | 8 | Isolated option | Two-pack options available |
| AEDIKO 8 Channel Relay Module DC 5V | AEDIKO | 5V | 8 | Isolated | Opto-isolated, high/low trigger |
| 8-Channel I2C Relay Board XL9535 | IotMug | 3.3V/5V | 8 | Optional via I2C expander | Dual power modes, USB-C |
SunFounder 5V 8 Channel Relay Shield Module
SunFounder’s 5V 8-channel relay shield provides a standard interface compatible with Arduino and many other MCUs. Each relay requires 15-20mA driver current and offers AC 250V 10A and DC 30V 10A ratings. The board is designed for straightforward direct control by microcontrollers, making it suitable for hobby projects and educational setups.
ELEGOO 8 Channel DC 5V Relay Module with Optocoupler
ELEGOO’s 8-channel 5V relay module uses optocouplers to improve isolation between control logic and relay coils. Each channel draws about 70mA. Relays support normally open and normally closed contacts, with indicator LEDs and coil protection. Jumper-selectable drive mode and TTL/ground options enable flexible integration with multiple microcontrollers.
DEVMO 8 Channel DC 5V Relay Module Board
DEVMO’s 8-channel module keeps control simple with 5V logic and high-current relays rated for AC 250V/10A and DC 30V/10A. Each channel features normally open and normally closed contacts, with a status indicator to monitor activity. Optional opto-isolation improves performance in noisy environments while maintaining compatibility with common MCUs.
AEDIKO 8 Channel Relay Module DC 5V
AEDIKO’s 8-channel module offers opto-isolated control with high/low trigger options via jumper settings. It supports up to AC 250V 10A and DC 30V 10A loads. The module is designed to allow individual relay control through opto-isolated digital inputs and includes a coil protection diode to damp back-EMF.
8-Channel I2C Relay Board XL9535
The I2C-based 8-channel board uses the XL9535 expander and provides eight SPDT relays rated up to 10A at 250VAC or 30VDC. It supports dual power modes for 3.3V and 5V MCUs, with USB-C power input for convenience. Independent logic and relay power rails help reduce MCU resets and I2C errors in complex smart-home or automation setups.
Buying Guide: Key Considerations for 8-Channel Relay Boards
- Voltage and logic level: Choose 5V boards for most Arduino projects or 3.3V/5V compatible boards for ESP32 or Raspberry Pi. Some models offer dual-power modes to match different MCUs.
- Isolation: Opto-isolated inputs or optocouplers improve protection from relay coil noise. Decide how much isolation you need based on your environment and needed protection for control electronics.
- Drive current per channel: Check how much current each relay draws. Higher drive current may require more capable drivers or isolation.
- Contact ratings: Ensure the relays handle the loads you plan to switch (AC or DC, voltage and current). Typical ratings include AC 250V/10A and DC 30V/10A.
- Indicator and protection features: LED indicators help debug, while diode protection on coils reduces back-EMF; look for modules with these features if reliability matters.
- Trigger type: Some boards are active-low, others active-high. Verify compatibility with your microcontroller’s logic level and wiring.
- Power supply considerations: Some boards provide separate logic and coil power rails to prevent MCU resets. USB-C powered boards can simplify power setup.
- Physical form and mounting: If using a Pi or a compact MCU, consider form factor, screw terminals, and whether the board fits your enclosure or DIN rail setup.
- Expandability and future use: If you anticipate expanding to more channels or adding I2C or other interfaces, choose boards designed for expansion or multiple control methods.
- Cost vs. reliability: While many 8-channel boards are affordable, verify build quality, wiring layout, and available documentation to ensure long-term reliability for automated systems.