

Currently this is more of a proof-of-concept work and security was a big problem when developing. NfcService requires several permissions declared as system|signed which means it has to be signed with the same certificates used to sign the remaining system. I did not manage to do that, so I patched services.jar to ignore bad certificates.



(This paragraph is deprecated) When device boots even if NFC adapter is active, it does not get full power right away. Instead, it sets up a BroadcastReceiver to catch ACTION_SCREEN_ON and ACTION_SCREEN_OFF events to power the module only when screen is lit. However, power manager service on SmartWatch 3 never sends these broadcasts, so the module never gets a signal to turn on. I am yet to figure out why, in the meantime I patched NfcService to turn the module regardless of current screen state. It does not start consuming power until a tag is first detected, after which the battery can be drained with rate up to 50% per hour.

