The cheapest rubber ducky

And how I changed its keyboard layout

Some time ago I wanted to buy a Rubber Ducky, but the price ($49.99 while I’m writing this article) was too high for what I wanted to spend. Surfing the internet I found an alternative to the Rubber Ducky: the Digispark from Digistump.

It’s a tiny development board based on the tiny85 chip (same chip family used on Arduino).

It’s less powerful but (much) cheaper, you can consider this digispark board as micro Arduino board with very basic features.

Those are the main differences between the two peripherals:

Pretending to be a keyboard

Both Rubber Ducky and Digispark can work the same way: they are recognized by the computer as an HID (Human Interface Device) and act just like a normal keyboard would.

So the idea is to act like a keyboard, but typing faster than a human can do.

Using one or the other doesn’t make much difference, it will write much faster than you, so much that it is sometimes invisible.

My problem with Digispark

As there are a lot of tutorials on the internet about how to set up the Digispark and make this tiny board work with Arduino IDE, I’ll jump to my problem: the Digistump library only allows US keyboard layout.

That’s not a big problem if you only use standard numbers and letters, but it’s impossible to use symbols. I needed an Italian keyboard layout to let the board write on Italian computers 🇮🇹

The solution

After a couple of hours trying to match the keystrokes to the different keyboard layouts, I decided to do some researches, finding something interesting on www.usb.org: a pdf containing all the HID Usage Tables (you will be astonished by how many things you could do with a Digispark and this document)

If you search in the Digispark library you will find a file named DigiKeyboard.h and analyzing it, you will notice something similar to the pdf mentioned above: keyboard scan codes.

On page 53 of this document, you can find the table containing the Hex code for each key on your keyboard (and some more cool functions that most keyboards do not have).

That said, it was easy to bring a solution to my problem, swapping keys and scan codes, matching my keyboard layout. I then forked the Digistump repo and made an Italian version of it, ready to use for whoever needs that keyboard layout.

A little example

If you want a little demonstration of what a Digispark can do (and trust me when I say little ), here you are a script that you can write on Arduino IDE to create a text file on Windows computers:

//create a text file on desktop with a message

    #include "DigiKeyboard_It.h"  
    #define D 200  
    void setup() {
    }
    void loop() {
      DigiKeyboardIt.sendKeyStroke(0);
      DigiKeyboard.delay(D);
      DigiKeyboardIt.sendKeyStroke(KEY_R, MOD_GUI_LEFT);
      DigiKeyboard.delay(D);
      DigiKeyboardIt.print("cmd -k cd %User%");
      DigiKeyboardIt.sendKeyStroke(KEY_ENTER);
      DigiKeyboard.delay(D);
      DigiKeyboardIt.print("cd Desktop");
      DigiKeyboardIt.sendKeyStroke(KEY_ENTER);
      DigiKeyboard.delay(D);
      DigiKeyboardIt.print("echo Ciao! > Aprimi.txt");
      DigiKeyboardIt.sendKeyStroke(KEY_ENTER);
      DigiKeyboard.delay(D);
      DigiKeyboardIt.print("exit");
      DigiKeyboardIt.sendKeyStroke(KEY_ENTER);
      DigiKeyboard.delay(D);
      for (;;) { } 
    }

Conclusion

Well, now you know that you can practice with a Digispark before buying a faster device such as Rubber Ducky!