Approximately a year ago, the author moved into a new apartment and discovered a mysterious touchscreen with no indication of its purpose. After some investigation, they learned that it is part of an energy monitoring system. They also found a second device connected to the electricity meter. The devices communicate using WiFi, which is common in IoT devices. The author found a way to turn on the touchscreen, which turned out to be an old Android tablet. The interface was disappointing, but the author discovered that it runs on Socket.IO, a surprising choice. They decided to hack into the device and found a node.js server running, but struggled to crack the root password before finally gaining access. The device runs on Linux 3.10 and has an ARM9 CPU. It also has a surprisingly large amount of RAM. The author refrained from releasing the source code to avoid legal issues.
https://laplab.me/posts/whats-that-touchscreen-in-my-room/