2 Channel DC 5V Relay Module with Optocoupler Low Level Trigger Expansion Board Compatible with Arduino R3 MEGA 2560 1280 DSP ARM PIC AVR STM32 Raspberry Pi

I purchased this SunFounder 2-channel 5V relay module for a small electronics project, and it works exactly as advertised. The board is well built, clearly labeled, and easy to integrate with a microcontroller (Arduino/ESP-based setup). The optocoupler isolation is a nice safety feature and gives extra confidence when switching external loads. Both relays trigger cleanly at 5V, and I’ve had no issues with false switching or noise. Screw terminals are solid and make wiring straightforward. Overall, this is a reliable and beginner-friendly relay module that’s great for automation, DIY projects, or learning electronics. Good quality for the price — I would definitely buy it again.

The relay works very well with Arduino. Simple wiring and the relay is operating properly.

SunFounder 5V Relay Shield Module for Arduino UNO 2560 1280 ARM PIC AVR STM32 (4Channel) I am extremely happy with this board. It works flawlessly with the Arduino. It is responsive and VERY easy to use. Remember though, that its logic is Active Low, so when power is first applied from the Arduino, the low state of the pins causes the relay to turn on until the Arduino has time to set them to active high, thereby turning them off. I solved this problem using a 2N2222 transistor and a 1k Ohm resistor between an Arduino pin and the 5 volt input to the relay. Now, when the Arduino powers on, there is NO power to the relay board UNTIL the program tells it to do so. GREAT PRODUCT - HIGHLY RECOMMENDED!

visible quality, works good, good specs

Works as advertised but this is a replacement. The first one died after 3 years

Bought this relay board to make a remote control for physically disconnecting a comm bus at a remote site to allow for troubleshooting. It works well being controlled with an arduino.

If you are truly looking to decouple and isolate the device controlling the relay (such as an Arduino, etc) from the relay coils to provide true optoisolation, you must connect it in the following way: Remove the jumper from the JDVCC pin, connect power from a separate 5v power supply to the JDVCC pin and ground from the separate 5v power supply to either of the Gnd pins. Next connect the 5v pin from your controlling device (arduino) to the VCC pin on the 10-pin header of the module, and connect your I/O pins from the Arduino to the 8 control pins. The opto-isolator will get the 5v signal from the Arduino, and the Ground from the Arduino when you perform a digital write LOW on the I/O pin, completing the circuit, and that control circuit is completely isolated from the relay coil power circuit. The gotcha with this board is that the Gnd pin on the 10-pin header and the Gnd pin on the JDVCC/VCC/GND header are actually connected on this board. This means if you connect your Arduino Gnd to either of the Gnd pins on the board, you have now tied your Arduino to the separate 5vdc power supply (which you might not want to do). With all 8 relay coils activated, the board draws 472mA of power - about 50-55mA per relay.

resultó muy práctico y funcionó correctamente desde el primer uso. Es una solución sencilla y confiable para proteger y estabilizar mis proyectos con Arduino.