HiLetgo2pcs 5V One Channel Relay Module Relay Switch with OPTO Isolation High Low Level Trigger

compact and works as stated

Wiring was super intuitive and everything just worked. I was able to power, ground and provide signal all from Arduino and then pull 12V DC from a 4A dedicated power source and connect it directly to the 12V DC magnet when the relay receives a signal. Perfect solution for my secret bookcase door project!Only note was that the relay screws needed the perfect sized screw driver because it felt like it was going to strip with the one little screwdriver I use for everything so I had to get a new small screwdriver kit and then i was able to repeatedly install and change configurations on this board without any problem.

The media could not be loaded. I need to pulse some fuel injectors off an engine for cleaning and testing purposes so I have this relay connected to an ESP32 and basically just modified the standard 'blink' code to blink really fast. But instead of it blinking an LED directly, it was triggering the relay. I used a small 12V to 5V buck converter scavenged from an old car/lighter phone charger to power the ESP32 and relay from a 12V adapter, then just fed the 12V+ into the COM port of the relay and connected the NO to the load, and voila, every 60ms the relay completes the circuit and fired the injectors just as I needed. The video shows a 12V LED I used for testing, but same principle, and everything worked flawlessly.

Fast and secure shipping in these. When I opened the package it was a pleasant surprise to find that the pieces were individually bagged in Mylar ESD protection packs. So far, I have only opened one and the quality feel of the plastic made me confident that I can trust that one to work. As the two-pack has two of the same items, I am just as optimistic the second one will perform in my hand the same.Most easy hookups on this! See my schematic picture.With the chip shortages and rising price of oil, I just know these can only go up in value. That brings me to the reason one star was deducted. These are currently being sold at the same price as I paid. Good news for you, bad news for me. Buyers, don’t miss out!

Easy to implement -I didn't try powering it from VCC but rather used the 5 volt pin on the arduino - all you have to do is set the pin as output in setup and then switch from low to high to trigger... Easy peasy

The relay works perfectly fine with an Arduino and is incredibly easy to implement (and there are lots of youtube videos to show you how). The relay clicks each time voltage is applied or dropped. If the state of the relay doesn't change much for your application, you should be fine. If there's a lot of change happening (such as a high contribution from the derivative part of your PID loop and you're not averaging or implementing a threshold for using the derivative control), then hopefully you like hearing clicks.

I've attached a photo of the relay module schematic. I Ohm'd and traced it out. Now the function of the 2-pin jumper is fairly clear. In my case, I want the coil to be active when the input (IN) is a logic high (3.3V) from an Arduino. Thus, I want the jumper as shown in the schematic (photo).

Seen better soldering but they are okay and work as they should.