Every since I read about Positive Security’s Send My project that is able to upload abritrary data from devices without an internet connection by (ab)using Apple’s Find My network, I thought the RuuviTag would be an interesting development platform for this idea. So recently I ported the project’s ESP32 firmware to Zephyr and managed to run it on the RuuviTag:
After flashing the firmware to your RuuviTag (you need the RuuviTag Development Kit for it), it sends out Bluetooth Low Energy advertisements with sensor data that will be visible in Send My’s DataFetcher application in macOS because Apple devices in your neighbourhood pick up these packets and forward them to Apple.
This is just a proof-of-concept, only reading and sending the built-in BME280’s temperature sensor data. There’s also no power management yet. Reception of the data doesn’t seem that reliable, but maybe that’s because I have just one Apple device picking up these BLE packets. I’m curious whether other RuuviTag fans have better success with reading the sensor data.