I went in touch with this powerful hardware thanks to my friend Alexandre Poltorak, during a very interesting meeting held in Bienne/Switzerland. This is a device which can be used to make signatures of your Bitcoin transactions, thanks to a very well done firmware.

One of the most interesting thing, in my opinion, is that it uses general purpose hardware, nothing that can be necessarily linked to a wallet. It is airgapped infact you can sign using QR Codes (through the scanner) or by SD card which reader is built-in.

Another peculiarity is that the mnemonic is not held by the device. You just import it during the session and forget as soon as you power it off. It supports also BIP39 passphrase. The device can be used also in a multi signature setup.

You can import by typing all the words set or you can get the same result by scanning a QR Code. The QR code can be copied to a piece of paper or a piece of metal at first time initialization. Obviously you can use the words generated by the device of you can geneate the words separately with a different device, dices or any other preferred method.

View on the board

Inspection of the Hardware

How cables are inside the case

Please note how the scanner cables are connected to the board

Hardware basic requirements

1) Development board STM32F469I-DISCO. I have found this board at a reasonable price at the following shop. But obviously search it in the nearer shop.


2) Micro USB Cable
3) Mini USB Cable
4) Optical Scanner. This is a cheap scanner, which works quite good. I have shopped it here:


5) Case. The case is printed 3D from this project. It closes without screws.