8 Channel DC 5V Relay Module for Arduino Raspberry Pi DSP AVR PIC ARM

Well make,, I give 4 stars due to many pins were bended so I had to adjust, luckily not broken. but in general the product is great.

I purchased this relay module to do some prototyping. It has worked well with the boards I have in house at the moment: * Raspberry Pi Model 2 B V 1.1 * ST Nucleo F411RE.Both of these have 3.3V GPIO pins, but the array worked fine when wired correctly. Please keep in mind the maximum current your micro-controller can drive. Both the PI and the Nucleo can operate a few of the relays, but you'll probably need a separate 5V supply to operate all 8.There are a number of good tutorials on how to utilize a relay array with the pi. There's a little less documentation for the nucleo 411 RE, still everything worked on the first try. I wired the following pins from the relay board to the pins in the CN7 connector on the nucleo: * VCC to pin 18 (+5V) * GND to pin 22 (GND) * IN1 to pin 17 (aka PA_15) * IN2 to pin 15 (aka PA_14) * IN3 to pin 13 (aka PA_13)Then I wrote the following code:#include "mbed.h"DigitalOut myled(LED1);DigitalOut relay1(PA_15, 1); //high is offDigitalOut relay2(PA_14, 1);DigitalOut relay3(PA_13, 1);int main() { set_time(1436486851); while(1) { time_t seconds = time(NULL); myled = !myled; relay1 = (seconds % 3 == 0 ? 0 : 1); relay2 = (seconds % 3 == 1 ? 0 : 1); relay3 = (seconds % 3 == 2 ? 0 : 1); wait(1); }}Sure enough, the nucleo kept 1 out of the 3 relays I had wired on each second, and cycled between them.

Not good

Worked fine out of the box. I am using on a Pi 3 and the relay module seems stable and reliable using just the +5 and GND from the Pi. The relays are mechanical, and not silent. For my purposes (experimenting and prototyping) the ability to hear each one trip is helpful (I *know* the code executed when I hear it), and I really consider this a surprisingly good deal.Make sure you have 10 M-F jumper cables if you're connecting to a breadboard (8 relays, 1 +5vdc, 1 gnd)Also - this is an unmounted PC board. Make sure you do not leave anything conductive under it. (a sheet of paper is fine while experimenting, but you'll want to mount this properly before running current through the business end of the relays!)

Had an orbit sprinkler system with a "wireless" remote. It was wireless but only up to about 6' away. Probably rf interference from wifi, but didn't care to fix it.Built a much better controller, using opensprinkler running on an rpi zero w. Mounted everything to an old tiny cutting board and mounted to the wall.Used these to control the valves. They're running 24VAC and have been working great for a week now.I left the VCC / JD-VCC jumper connected and just used the power from the pi's 5v out to power 2 of these. Seems sufficient for my needs.When I move to automating Christmas lights, I'll probably look to these relays again.