Reverse engineering a BLE clock
Perfect Time

© Photo by ANIRUDH on Unsplash
What do you do when all your Bluetooth clocks show slightly different times? With some reverse engineering, you can write a Python program to synchronize your clocks.
A while ago, I bought a ThermoPro TP358, a Bluetooth Low Energy (BLE) digital thermometer with a display. The ThermoPro shows the temperature, humidity, and air comfort indicator, as well as the time and day of the week. Its big display is nice for immediate feedback, but the device also lets you read its values and view graphs in the ThermoPro Sensor app, available on Android and iOS (Figure 1). Moreover, every time you connect to the device with the app, it synchronizes the time.

While that is a nice feature, I have a couple of other types of Bluetooth sensors with a clock, and I didn't want to use multiple apps to view the sensor measurements and synchronize the clocks. For the sensor measurements, a solution already exists: Software such as Home Assistant [1] supported my devices out-of-the-box, letting me view their measurements in Home Assistant's dashboard. However, I couldn't find any solution that let me synchronize the time across all of my Bluetooth clocks without using the individual apps.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
Linux Mint 20 Reaches EOL
With Linux Mint 20 at its end of life, the time has arrived to upgrade to Linux Mint 22.
-
TuxCare Announces Support for AlmaLinux 9.2
Thanks to TuxCare, AlmaLinux 9.2 (and soon version 9.6) now enjoys years of ongoing patching and compliance.
-
Go-Based Botnet Attacking IoT Devices
Using an SSH credential brute-force attack, the Go-based PumaBot is exploiting IoT devices everywhere.
-
Plasma 6.5 Promises Better Memory Optimization
With the stable Plasma 6.4 on the horizon, KDE has a few new tricks up its sleeve for Plasma 6.5.
-
KaOS 2025.05 Officially Qt5 Free
If you're a fan of independent Linux distributions, the team behind KaOS is proud to announce the latest iteration that includes kernel 6.14 and KDE's Plasma 6.3.5.
-
Linux Kernel 6.15 Now Available
The latest Linux kernel is now available with several new features/improvements and the usual bug fixes.
-
Microsoft Makes Surprising WSL Announcement
In a move that might surprise some users, Microsoft has made Windows Subsystem for Linux open source.
-
Red Hat Releases RHEL 10 Early
Red Hat quietly rolled out the official release of RHEL 10.0 a bit early.
-
openSUSE Joins End of 10
openSUSE has decided to not only join the End of 10 movement but it also will no longer support the Deepin Desktop Environment.
-
New Version of Flatpak Released
Flatpak 1.16.1 is now available as the latest, stable version with various improvements.