Attention commands

The HC-05 is one of the most popular Bluetooth modules in the Arduino ecosystem, and for good reason. It's affordable, well documented, and flexible enough to handle a wide range of use cases. It can operate as both a master and a slave device, meaning it can initiate connections to other Bluetooth devices as well as wait for them. For projects where you just need a phone to talk to an Arduino, that distinction doesn't matter much. But for anything more involved, like two Arduino boards communicating wirelessly, the HC-05 is the right tool for the job.

Every developer has been there: you push a commit, CI fails, and it turns out there was a linting error, a forgotten debug statement, or a test that nobody ran. Pre-commit hooks are the safety net that catches these problems before they ever leave your machine. They are not a complex feature or an advanced Git topic. They are just scripts, and once you understand how they work, you will find yourself reaching for them on every project.

Getting two Arduino boards to talk to each other opens up projects that a single board can't handle on its own. You might have one board reading sensors in one corner of a room and another driving a display somewhere else, and the two need to share what they know. Serial communication is one of the simplest ways to make that happen, and it works with almost any Arduino model you have lying around. This article walks through connecting two Arduino Nano boards and passing data back and forth over their serial ports.

Images are almost always the heaviest thing on a web page. A single hero photo can weigh more than all the HTML, CSS and JavaScript of a site put together, and every extra kilobyte delays the moment a visitor finally sees something useful. Search engines notice it, and users on mobile data notice it faster. The encouraging part is that image delivery is one of the few areas where the fixes are well documented, mostly automatable, and visible in the metrics almost immediately.

Adding wireless communication to an Arduino project usually starts with a Bluetooth serial module, and the HC-06 is one of the most common choices. It's cheap, widely available, and does one job well: it lets a phone or computer connect to your board and exchange data as if the two were joined by a cable. Four pins, one operating mode, and a small set of configuration commands is the whole picture. That simplicity comes with a real constraint though, and knowing it upfront saves time later, since the HC-06 only accepts incoming connections and can't reach out to another device on its own.