Flipper Zero has a built-in 1-wire connector to read iButton (DS1990A) contact keys. This technology is quite old but still widely used around the world. It is also known as TouchMemory or Dallas keys. They work on the 1-Wire protocol and don't have any authentication, so they could be easily read. Flipper can read these keys, save IDs into the memory, write IDs to blank keys and emulate the key itself.



Flipper Zero has a unique contact pad design on the corner — its shape works as a reader and simulator at the same time. The central pad of iButton keys is positive contact and the outer ring is ground, so you need to lay the key in the correct position. The same contact pad can be used to simulate keys from the memory — just touch the reader with it. This mode could also be handy to silently intercept the 1-Wire data line.

