Working with headphones on usually means you'd rather not be bothered, but sometimes it means you're just listening to something while you work. If you want to be available despite your cans being on, why not build your own alert button?
Enter developer Nick Sypteras, who wanted to solve the problem of coworkers requesting his attention while his headphones were on. Working in a cubicle, he wrote, "There's no way for a visitor to my desk to get my attention other than by waving their hand in my face, making loud noises behind me, etc." So he broke out the soldering iron, a Staples Easy Button, and an Adafruit microcontroller.
Dear Lifehacker, I am condemned to being stuck in a small cubicle with low walls. I know Lifehacker has plenty of showcases for home offices, but what do people like me do when they work in an office? I'd like some advice on what to do to make my cubicle a more comfortable and less sterile place.
Sypteras wrote the code to send his Slack alerts in MicroPython, a version of the programming language designed for microcontroller boards. The Adafruit Feather HUZZAH microcontroller listens for a change in value based on whether the button was pressed.
Using Slack's API, he was able to send messages to a private channel he created specifically for his desk's easy button. While the message just lets him know he's got a visitor, you can get fancy with it and use Slack's API to attach more info to your alerts.