FakeTag

Disclaimer

This project is not meant to be used by beginners. While it is based on OpenHaystack, it is not compatible with it. The keys are generated by an undisclosed mechanism, the date is fetched and decoded by a private project. I am not planning on making this a easy-to-use project.

Summary

firmware for nRF51 chips that is coincidentally compatible with the FindMy (AirTag) ecosystem.

You can read about this project here.

It sends out advertisement keys defined in keys.h, rotating keys every hour.

Also, an input pin can be defined. Whenever that input pin is triggered, the status byte increments by one. The first two bits of the status byte contain battery information, the other six bits contain the counter in my code.

I use this for my Mailbox-sensor. There is a vibraion sensor attached to the board, and whener the Mailbox is opened the vibration sensor triggers, which makes the chip send out a different status byte. That status byte, traveling through the FindMy network and OpenHaystack, reaches my smarthome and I get a notification.