Confused regarding a specific dev board

So I was looking for the smallest (and flattest) possible board based on a powerful MCI. I already have the Digispark Tiny85, which I like very much and I was hoping to find something similar or even smaller but featuring a more powerful chip. I did find some microscopic boards but they had plugs and other stuff soldered to them that made them chunky. Then I found this:

It looks like a Digispark Tiny85 except with a leonardo instead, which would be perfect. Thing is there's this confusing stuff in the description that is throwing me off...

Bad USB?
Keyboard??
CJMCU???

WTF is this stuff and does it matter? Whatever it means, I don't want it. I just want a good old leonardo chip that will do what I tell it to do, not something rigged to be an evil keyboard.

Also, if anybody has owned one of these, your experiences would be much appreciated!

Bad USB seems to be about the form factor of the board. Small devices like this have been used to show hacks of PC system via USB.

One of the ways to attack PC via USB is to have a USB device that enumerates as a keyboard. There is little you can do to protect yourself against that because USB does not have protection against malicious devices. So, people looking for this kind of board would use that as search term.

If the board comes from a trustworthy source this might just be a case of bad marketing. Trying to sell the board to people who read a hacking blog and want to try this.

If you look for more processing power you could look for a 32bit Cortex-M board. Google "tiny Arduino Cortex"

I found this. Seems cheaper than the board in your link and has a much more powerful processor. :slight_smile:

I have not tested the board myself, but it looks neat.

Much appreciated, though I was actually looking to stay with the old 16MHz chips.

So that bad usb whatever thing... it's just an ordinary leonardo? I mean maybe they marketed it as a hacking device but can I use it for general purposes or do you think they messed with the bootloader or something?

DFRobot seems to be the manufacturer; they are reputable. So I doubt they modified the bootloader; if you don't trust it, you can always burn the Leonardo bootloader via the ICSP header.

Product page: https://www.dfrobot.com/product-1075.html

Wiki: Beetle_SKU_DFR0282-DFRobot

I believe you've got a different variant there. DFR makes a cut down version but if you check my original link, this is a bit denser of a product I'm considering.

I should probably just buy it. A chip is a chip. As you said, I can always re-burn it.

Gahhhrrrlic:
Bad USB?
As mentioned this is a microcontroller that natively supports USB and has a USB connector so can be enumerated as a HID device (keyboard/mouse/joystick/etc) by the computer it's plugged into. The idea is it looks like a keyboard when plugged in but it can inject it's own keystrokes to run scripts to do good/bad things.
Keyboard??
As mentioned above the microcontroller can look like a keyboard to the computer it's plugged into.
CJMCU???
Just the manufacturer of the board your looking at.