Pro micro issues after usin ISP

Hi all,

Total noob to this so apologies in advance.

I’m trying to make a button box for PC gaming. I have followed some online tutorials and have downloaded a sketch to run the box. Sketch designed for a pro micro.

I’m have purchased a few pro micro boards online, not originals, copies.

The first thing I noticed was that when connected to the Arduino sketch software the boards show up as Lilypads, not micros.

I tried to load the sketch into the board with Arduino Micro as the board type and on both boards the “Bricked?”, I.E no longer recognised as a USB device.

SO, having searched online and found I can use my uno as an ISP and reload the bootloader, I tried that. connected it all up, found the correct pins etc, ran the Arduino micro board bootloader and all seemed to work, had no errors on the leds, and no errors on the sketch.

But its still not working, just that now after the bootloader install, whilst the red LED is lit on the pro micro, its not being recognised and the reset function doesn’t do a thing.

I’ve ordered some more pro micro boards as well as a Leonardo to try them tomorrow but it could get expensive.

Any advice much appreciated.


Please post a link to the product you bought.

Names and descriptions of clone boards are sometimes misleading.

A pair of these.


The LilyPad runs at 8 MHz, while the genuine Pro Micro, Micro, and Leonardo run at 16 MHz. The fact it was identified as a LilyPad makes me suspect the board you got has an 8 MHz crystal/resonator.

If so, when you uploaded a sketch that was compiled for the 16 MHz clock of the Micro, it caused the timing sensitive USB code to stop working (because it was running at half speed). This explains why it was no longer recognized. Then when you burned the Micro’s bootloader to the board, the same happened, since that bootloader was compiled for a 16 MHz clock.

So my advice is to select Tools > Board > LilyPad Arduino USB and then try burning the bootloader again. After that, compile and upload a sketch, still with Tools > Board > LilyPad Arduino USB selected. If it then works fine, you’ll have confirmation that your boards use the 8 MHz clock and you can simply continue to use them as “LilyPad Arduino USB”. It’s likely that you will have no problem using the 8 MHz board in place of the 16 MHz board.

A pair of these.


Aha, that confirms they are 8 MHz. So go ahead with my suggestion.

The advantage of the 8 MHz boards is you can run them at 3.3 V, which would be out of spec for a 16 MHz board.

I love online forums and people who know their onions.

Thank you Pert.

So I have changed to Lilypad Arduino USB and BAM, its now showing as a COM port and back to Lilypad.

So, as I have downloaded a sketch created by somebody else for the 16mhz micro pro, am I to assume it will not work for this Lilypad?

Sorry again for the stupid questions.


A pair of these.

This is an "ATMega 32U4 running at 3.3V/8MHz".
So not a "normal" Micro (which ist running at 5V/16MHz).
It is more like this: Pro Micro - 3.3V/8MHz - DEV-12587 - SparkFun Electronics
or this: FLORA - Wearable electronic platform: Arduino-compatible [v3] : ID 659 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits

To use it you have to "install" the proper board in Arduino IDE.
Take a look here: Pro Micro & Fio V3 Hookup Guide -

There are different bootloaders for different clock rates (like 8MHz vs. 16 MHz).
"Normal" Arduino micro board bootloader will not work.

Yes I see.

OK, well they are working well now I have uploaded the sketch to them using the Lilypad option.

Thanks for all of your help, its been a frustrating day

Good to hear that it is working now.

So, as I have downloaded a sketch created by somebody else for the 16mhz micro pro, am I to assume it will not work for this Lilypad?

It will almost surely work. >99.9% of Arduino code will automatically adjust to any clock speed. It is certainly possible to write code that only works at a specific clock speed, but Arduino code tends to be written with portability to many different boards in mind, so it’s not at all common.

In general, you probably won’t even notice a difference between an 8 MHz and a 16 MHz board. Sure, for a very processing intensive sketch you might, but many sketches just have the processor sitting there waiting most of the time, and it doesn’t matter what the clock speed is while it’s doing that.

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