Category Archives: Android

RaspMatic + HomeMatic (IP)

Some time ago I bought a Raspberry Pi 3B with the RPI-RF-MOD extension module and the corresponding case. It’s also possible to buy all in a set: Buy link (I am not affiliated). There is an image available that works like a charm for this setup, whcih can be found here. Multiple models are supported, so make sure you download the correct release.

I am very happy with this setup. HomeMatic provides a multitude of different devices ranging from simple sensors (temperature, light, …) to quite sophisticated weather stations. There are also actuators available for heating control, blinds/shutters to alarm sirens. What is even more interetting is that general relays and comunication modules are available, so you can also build your own smart home devices!

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Backup of Google Authenticator data

In case to got a new phone and want to move the Google Authenticator you will need to move the secrets from all the sites you added to the app. Or you are just curious what is actually being stored on your phone 🙂

Since I usually use the QR-code to create a new entry creating a backup is usually quite troublesome for me; I simply have no idea how to recreate the entries. But, its possible to download the apps database using adb. Well, that is if you have a rooted phone.

First you need to enable the adb USB-debugging somewhere in your settings. This depends on your phone, so you will need to look online on how to do it in your case.

After that you can connect using adb:

 :~$adb root

The root is important since otherwise you will not have access to the app-related database files. Next we can copy the authenticator database that includes all the entries of the app.

:~$ adb pull /data/data/
196 KB/s (16384 bytes in 0.081s)

Finally, we are able to open the sqlite3 database and print the info we need. I replace the actual output with some meaningless text, but its clear what the secrets are.

:~$ sqlite3 ./databases
SQLite version 2013-01-09 11:53:05
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite>select * from accounts;

And that was it. Now you only need to re-add the secrets in the new phones authenticator app and you’re done.