HiLetgo 3pcs Atmega32U4 5V 16MHz Bootloadered IDE Micro USB Development Board Microcontroller Compatible to Arduino Pro Micro Serial Connection with Pin Header

All three units functioned well. At first, I had a problem with my old Windows 7 computer recognizing the device. I was able to upload a sketch to it, and once I had done that, then the computer located the proper device driver for it. Not sure how that worked, but it did. They all worked fine with a Windows 10 computer. I was able to run a few simple programs, including one emulating a USB keyboard.One thing to note, when writing a sketch to output to the UART, you must use serial1.begin() (and associated serial1.xxx functions) not serial.begin(); The USB port does NOT share the UART pins as is the case on a UNO. If you have code that writes to the USB port, the program will not run until you open the serial monitor. If you write to the UART, it will run regardless of whether you have anything connected to the USB port or UART pins, but the output will only go to the UART pins.

For the value these are great little Arduino compatible Leonardo Atmel32u4 boards. I wish there were a schematic for them. Then I'd know that the LED typically on pin 13 is actually on pin 17, and a bonus LED on pin 30. (Thanks to other commenters for the heads up on that) Another problem I ran into: When programming these modules I got my LED blink test code to work then suddenly, without any warning, ~10 seconds later, I got an error message on my PC telling me that the device's USB had failed. Sure enough I couldn't download code to the module; however, I knew that the module didn't fail, it was still running running my LED blink code. The PC didn't recognize the device no matter what I did like unplug and plug it back in... it would make the USB connect and disconnect sounds, then display the error message again. To solve this problem, at least this worked for me so it's worth trying, connect to a different USB port on your PC, like I said, I have a USB hub; however that's not good enough to switch to a different one on the hub. You need to go to a completely different USB port on the computer... directly to the PC if possible. It should register this time without a problem, then, using the Arduino IDE, change the port number and it connected right up and I was able to program my modules again. I speculate, but there could be an issue with the USB and hubs, other devices plugged into the hub, I don't know. Anyway it's a great board at a great value, I plan to pick some more of these soon.

Does what it says on the tin. Make sure you use a good micro-usb cable! The first one I tried lying around the house didn't provide enough voltage, so it didn't boot correctly. However, in spite of the user error, the device booted well when I had a proper cable attached. I'm using it to drive an Adafruit trellis at the moment.

It does not work properly if the chosen board in IDE is "Pro Micro" - the timing is all wrong. Choose "Micro" or "Leonardo" and it works OK.Also I found it needs a hardware reset before a new program can be uploaded.

Let me just say these are packaged with care, which seems to be getting rare these days. (haven't tested the anti-static bags but they feel high quality, no suspicions here)I just love these little boards! I plan on using these to make custom gaming pads and a macro keyboard, super easy with the Arduino libraries. (Search for Arduino Keyboard / Mouse examples) These devices can be recognized as a keyboard, mouse, midi device, game pad (joystick/controller) and more in a few clicks just by using the Arduino libraries. I personally like these more than the ATMEGA168/328 boards.These are also breadboard/veroboard spacing compatible with the pins soldered on, allowing for super easy prototyping, my go to for simple sketches on a small breadboard.SparkFun made an awesome tutorial using these and some MX Cherry Switches to make a custom macro keypad for Eagle PCB, that's one thing I plan on doing with these. (will update with pictures if I remember :D)

I had been using Pro Minis in a project and decided to give the Pro Micro a shot because it had the onboard USB serial port which would make programming them easier. Everything worked great when we had them hooked up to the computer but a huge problem surfaced after we put them in the devices we were using them in. Once the power was cycled, the boards wouldn't immediately start executing the code. They would site there frozen until you did a reset by shorting the RS pin to ground (there isn't a reset button on the board). Once reset the board would then run the code just fine till the power was cycled again. This is a huge problem since the boards would not be easily accessed once the device was closed up. We also didn't want to have to force the user to reset the device everytime they cycled the power.Doing a little searching revealed this to be a problem with the Pro Micro design. I couldn't find a solution on the net.

Works with Arduino IDE out of the box. I can't seem to get arduino-cli to program it.Shipping envelop arrived as a thin plastic envelop with no padding at all. I was worried they would have been damaged in shipping but so far they seem fine.

See multiple other post about how to get this board running. I suspect some folks who think it's bricked don't realize the LEDs are not on pin 13 like for Uno.Instal the Arduino IDE, select Leonardo board and the correct port, open the blink example code and change the LED pin definition to pin 17 and/or 30. Notes that these LEDs turn ON when the pin state is written LOW. This is weird to me. Caused a lot of confusion getting buttons working. (Arduino typically is wired with a pull-down resistor and buttons pull the pin high. If you write the button state to one of the LED pins the LED behavior will be inverted.)Also, if you use this for a keyboard emulator you will need to plug the board in while you code compiles in order to catch the board at the right time during boot up or it will connect to your computer as a keyboard and the bootloader will be blocked. Having some sort of mode switch or jumper to enable the keyboard would be safer. See youtube for more info and help. Good luck!

Totalmente compatibles con el original de Arduino Micro, están bien fabricados y bien embalados, cada Arduino en su sobre antiestático. Las filas de pines vienen sin soldar, tal como muestran las fotos en el anuncio, lo que es muy útil si se van a utilizar en un montaje de cableado directo, porque es mucho más fácil soldarlos que des-soldarlos, si fuese necesario.

Ils fonctionnent tous avec un firmware QMK (firmware de clavier mécanique) comme tout bon Arduino pro micro, faut juste voir combient de temps les ports USB vont tenir en utilisation quotidienne.

Shipping was great on this item - arrived very quickly (UK). The boards are individually sealed in anti-static bags, with the header pins included but not soldered, which leaves your options open. I have now tested all 3 boards and they work fine with the Arduino IDE. It's a versatile little board and good value here - I highly recommend to others. Installing the driver can be a little confusing at first, but is straightforward. I have documented some instructions below to help other users:(1) Download the Arduino IDE(2) Plug the Pro Micro board into your computer. If the COM port does not appear in the COM port list in the Arduino IDE (go to Tools--> Port -->), the chances are you are using a charging USB cable, rather than a data USB cable - so use a cable you know works and communicates with other USB devices.(2) If you are happy with the USB cable, but still don't see the COM port In Windows, open Device Manager and navigate to Ports (COM & LPT). It should read something like 'Arduino Leonardo' (this is how the board is recognised by Windows). If things aren't working, there will be a yellow exclamation mark besides the Arduino Leonardo text. Right click on this and select "Update Driver Software" and "Browse my computer for driver software". Browse to your Arduino installation directory, something like "C:\Program Files (x86)\Arduino", make sure "subfolders" is ticked. Click OK and the driver should install (it can take a while).(3) In the Arduino IDE you should see a new COM port available (under Tools) - if not try restarting the Arduino software and confirming the "Arduino Leonardo" device appears in Device Manger without a warning exclamation mark.(4) You are now ready to upload sketches from the Arduino IDE! Try the "Blink" sketch first (File--> Examples--> 01.Basics--> Blink). Of note, the Pro Micro board (unlike other boards) doesn't have a builtin LED so the sketch will upload okay, but you won't see flashing. It has two LEDs that can be flashed, so try changing instances of LED_BUILTIN in the Blink sketch to 17 (RX LED) or 30 (TX LED). Upload the sketch and you should see some flashing!

Der Arduino funktioniert sehr gut.Ich verwende ihn um ihn als USB Tastatur an meinen Rechner anzuschließen. Mit den Beispielen der Arduino Bibliothek funktioniert das wunderbar.In Verbindung mit einem 433 MHz Funkmodul habe ich ihn auch getestet. Das Funktioniert ebenfalls sehr gut (die Funkt verbindung reicht durch das ganze Haus).Er ist zwar etwas teurer als die Arduino Nano nachbauten, die ich sonst meistens verwende, aber diese Funktionieren nicht als Tastatur, daher habe ich für dieses Projekt den Pro-Micro verwendet.Ansonsten sind die Unterschiede zum (etwas billigeren) Arduino Nano glaube ich nicht sehr groß.Fazit:- Funktioniert sehr gut- Lässt sich als Tastatur oder Maus am Computer anschließen- Sehr ähnlich zum Arduino Nano, aber für manche Projekte funktioniert nur dieser hier (oder ein noch größerer und teurerer)- Ich kann den Mikrocontroller wirklich nur empfehlen

This little micros are versatile and reliable. Make sure you choose the right voltage 3.3 or 5V. The built-in ability to emulate a PC mouse and keyboard is very handy for some projects. I’ve purchased many units from this seller with no problems.