HiLetgo 3pcs Pro Mini Atmega328P 5V/16M Replace ATmega128 Pro mini Atmega328 328P DC5V 16M for Arduino

My first attempt to use this device did not yield a good result. I watched a YouTube video that only showed connecting VCC, GND, RXI, TXO. I discovered that the DTR pin must be connected in order to program the device properly. Unit is working great now.

It was nice these came in a 3 pack. I need 3 for a specific Arduino project and these were perfect. I did not experience any issues at all using these boards.

These arduino pro minis work perfectly, came with pre-installed bootloader, so no issues there. I’m not sure why others reported differently. My code uploaded and ran perfectly first time. Very happy with this purchase!

Come on, the old boot loader? Otherwise OK. Like a NANO without the USB hardware. I had to reflash them so they would use the much more common boot loader.

We just got another set of these in and I have an official Arduino Pro Mini that I did the source code on. I moved my TTL programmer over one wire at a time based off the layout online since the programming header covers up most of the artwork. The board would not program. I looked at the board under a microscope to discover the artwork is inverted from what is online. So I put all the wires together on the official board. Tested it again that it talks. Then I tapped all the wires together and flipped them and put them in the HiLetGo Simple. And it works perfectly. So most likely everyone who said DOA had the same issue with the artwork being really hard to read and the layout being flipped. Overall, it's cheap and it works as advertised but the artwork on the board is not done well and confusing.

On my first board I made a mistake by connecting 12v power adapter to VCC line, which burnt out the board in matter of seconds! My bad. So, if you want to use them with 12v or so, make sure you connect it to the RAW pin, not VCC.

Subject says it all. I wish I had looked for negative reviews first. The one thing I needed was a steady 5 volts out of VCC (oddly labeled ACC) and it doesn’t do that. More like around 4.7 on the two I checked. And of course discovered after soldering into place. Might be useful for simple projects that only need output from the pins, but if you need regulated voltage for output you’ll be disappointed.

Did not run into any of the issues the other reviewers mentioned. I did not try a higher input voltage, however, just 5V. All headers were included, was able to program all of them, so they all had bootloader installed.