HiLetgo 5V 4 Channel Relay Shield for UNO R3 Relay Shield Four Channel Relay Shield for UNO R3

Received this, a couple of pins were bent, but nothing that a quick straightening didn't fix. As other reviews have said, there are 3 pins that stick down and will touch the shield of the USB connector on an Arduino. Place some electrical tape on it. This is not a worry for me as I am using this for prototyping and testing and not the permanent installation.

The pins are pretty thin ... bend easily ... But that makes it easier to plug into the Uno R4 WiFi boarduses data pins. 4,5,6 and 6You can stack two of these (cut off some of the longer pins in center of board). Then cut pins 4,5,6,7 and add jumpers from other gpio output pins

Great little relay shield for Arduino, just plugs right onto the board. Comes with no instructions, so had to perform an Internet search to figure it out. It's a little fiddly to mount on the Arduino, but not too bad. The one complaint I have is the screw heads strip very easily and the clamps don't hold the wire very well. Going to resort to soldering the wires. For as little as it cost, it works great and was a key component of my project.

Hits the USB connector on Arduino, been a problem for years, relay connectors hard to turn, documentation poor, code is not easy to find. Otherwise works good!

Product does work, but as some other reviews state it has its flaws. First being that the terminal blocks do touch on the USB connector. So cut the leads down flush to the joint and cover the top of the USB jack with electrical tape to avoid a short.. Then the pins are very flimsy and get damaged or bent very easily.. suggestion to the developer, use better pins that are a bit longer to lift the sheild higher up so not to impede the minimum electrical clearance and be less apt to bend. Or better yet.. lay out the board better to avoid the shorting issue

The shield is so poorly designed that the circuit board is against the USB jack before all the pins are making contact. Terrible design and quality control.

Lack of documentation is the only drawback. But another reviewer has done the hard work for us. It's a nice feature that there are LEDs that let you know the state of the relay.

Allows Arduino UNO to control high voltage systems through the relays for industrial control applications

The PCB appears to be of good quality and well assembled. However the pins were bent in 14 different directions. Since they were embedded in sponge, it is hard to imaging it happened in shipping, but rather at the supplier. As another remarked above, the connecting pins are remakably flimsy. The pins were so bent that it took me 15 frustrating minutes to align everything and mount it on the Arduino board. The headers for the boards the mount on top of this shield were also askew. Whether this occurred inshipping or assembly is difficult to judge.Although the blurb suggests that the unit will work with a 3.3V unit (I quote "4. High Drive (5V or 3.3V) normally open contact closure"), there are no specifications or schematics to check whether to transistors, together with the resistors are in fact compatible with a 3.3V input.

I should've gone through some of the reviews, but I didn't. I simply looked at the description, saw the price, saw the Prime delivery, and bought it. After all, who would think that something as simple as a relay board for an Arduino could turn into THIS level of trash?As others have rightly pointed out, the pins from the screw terminals come into direct contact with the metal USB connector on the Arduino. This can short out and kill not only your Arduino, but also the computer that you're using for programming it. That's in addition to bent pins, horrible quality of components using the absolute cheapest possible junk that they could scrape together, and the sheer sloppiness of the way in which the board was put together.Even after you take into consideration the fact that it's cheap Chinese-made garbage, this thing still manages to be astoundingly bad. China is famous for ripping off intellectual property and copying other people's work. But the absurd thing is that with this particular product, they didn't have to steal or copy or reverse-engineer anything because all of the original schematics from Arduino's relay board are available for anyone to see. And yet, despite that, they still managed to create this monstrosity which has the potential to not only destroy your equipment, but could very well create an electrical fire and burn down your entire home or business.It's actually quite infuriating that Amazon hasn't pulled these things off their site, especially when you consider that people have been complaining about the design problems since 2019.Avoid this thing like the plague. By doing so, you'll save yourself a lot of grief, and quite possibly save yourself from having to deal with the aftermath of your house or business burning to the ground. Go and buy the original relay shield from Arduino. Yes, it's a little more expensive, but the difference in quality is night and day.

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