Hacking old Galaxy Tabs for better living

Let's talk about the Galaxy Tab 3 10.1 P5210 a bit. A model released in July of 2013 it was already 2 years old when the construction of the building was complete and the apartments started selling.

(More specs at: https://www.gsmarena.com/samsung_galaxy_tab_3_10_1_p5210-5478.php)

It is a mid-range tablet with a modest resolution of 1280x800, just 1 GB of RAM and what puts it on the wrong side of history and in relative obscurity nowadays is its x86 architecture powered by Intel Atom Z2560. The device felt extremely laggy and in the years to come it would become apparent that putting the thing on permanent charging would require a sort of recall campaign where internal batteries would have to be replaced after becoming so swollen the screen would bulge out.

Besides having to consider the x86 architecture when exploring rooting/modding tools and when compiling my own, the 1 GB RAM meant that even the few background services needed to control the smart home, answer the apartment doorbell and receive IP intercom video calls would often get killed and the building was abuzz with unhappy neighbors that missed their visitor's calls.

At first I thought the whole building had the tablets running the same OS version - 4.2.2 Jelly Bean - but then I discovered some of them were upgraded to 4.4.2 KitKat which from Android prespective changed quite a lot under the hood.

I have been an Android developer since late 2009 and finding out every apartment was controlled with an Android tablet got my curiosity. In theory, it seemed like a great idea - why not use a fully developed project like a Galaxy Tab and attach every smart feature to it as an app?

But then I found out that despite paying for all of the smart home equipment, us homebuyers did not actually get any project documentation besides a simplified user manual - even the WiFi access point that connected the tablet and PLCs together with the high-rise internal network (for IP intercom calls and weather) was a "black box" with no SSID/password info and of course no admin credentials info either. I like to own my hardware, so that was a no-go for me.

Even before moving in completely I packed my laptop backpack with USB and ethernet cables and spent a few evenings sitting on the floor in the middle of my new empty apartment getting it to reveal its secrets.

I released the Galaxy Tab from its wall mount and first installed TWRP recovery on it and made a full backup which together with the internal /sdcard contents I stored safely away. Then I installed CF-Auto-Root and finally got access to /data/misc/wifi/wpa_supplicant.conf and the WiFi password which I noted down.