HiLetgo 2pcs UNO R3 Proto Shield Prototype Expansion Board with SYB-170 Mini Breadboard Based for Arduino UNO R3 ProtoShield

The quality I recommended

I do a lot of development on Arduinos and STMicroelectronics boards. Both have connectors that align with Arduino Uno V3 pin layouts. As a result, I have a LOT of breadboards laid out in different ways. Honestly, sometimes dealing with a full or half length bread board creates some added complexity, especially if the circuits I'm prototyping don't have many components. Sometimes it's easier to pop one of these on top of whatever dev board I'm using and wire up a quick prototype.I use my workbench for other things and it's easy to drop my dev board into a drawer with its circuits and get back to it another time. When I use a larger breadboard, I have to be careful of the wires connecting it to the dev board. Plus, if I want to see how a particular circuit, like a custom waveform generator, performs with multiple dev boards, it's much easier to pop one of these off and plug it into another dev board. No more disconnecting and reconnecting a few dozen wires just to test a custom wave form! It also reduces the chance of wiring errors going from one dev board to another.I bought 2 packs (4 boards total) and that seems to be plenty for my current projects.Overall rating: 5/5 stars

As noted in another review, the topside pin sockets are inset so this will have to be your topmost shield. I knew this going in so no problem there.There's no passthrough for the ICSP header but there is a place to connect your own since it's in a completely different place on the shield. Again, no problem for me because I don't need it, but this may be a problem for others.The pins aren't very long. I need to stack it on top of a DMX shield so I had to get an extra set of stacking headers (refer to the photo).... and it's those stacking headers that made me realize ... it's missing pins. The R3 has 3 extra pins (and one extra NC) that are not passed through. On the digital/PWM side, the AD4/SDA and AD5/SCL pins are missing, and on the Power block, it's missing the IOREF and an extra unused pin. Again, for me, none of this matters for my project, but it could be a problem for others.So with these deficiencies, why still 4 stars? Because it's cheap, it meets my needs perfectly, and got here quick.

These are exactly as described! I needed it for a small custom circuit that plugs into an old alarm system, and it's done it's part of the job nicely!

I typically have a lot of projects running at once. I use these boards to allow me to swap between projects without having to tear the old one apart or use another uno.

Many others have noted that the SCL/SDA pins are missing from this shield and the seller has been aware of this since 2018 and has still not fixed the product description. I bought these to use with a Wemos D1 R32 board which is plug-compatible with the R3.Updated review to add that these shields are not stackable and they have no available solder pads for wiring. HiLetgo shouldn't even be calling this a shield. Except for having a couple of LEDs and switches, this doesn't provide much benefit over just plugging Dupont wires directly into the Uno.Note to HiLetgo: This product could be nearly perfect with just a couple of changes. Use female headers with long pins and use a 10-pin header instead of 8-pin header to breakout dedicated SCL/SDA pins. This would free up the holes needed for soldering wires.

I built a fee things using these. Nice to be able to breadboard it first and then transfer to a permanent build on the board. I have built a few pieces of test equipment for testing other devices and they are really nice. I like that they have a reset button on the hat and a few other buttons and LEDs to use is a nice touch as well.

This is a good prototype shield but could be better. Lost one star for zero documentation. You need to trace the board to find the buttons, LED, headers, 5-volt, ground. Even after making a few, you still need to trace everything because without documentation who knows if anything has changed.