Hack a hat to remind you to reapply sunscreen

Absent-minded sun worshipers can retrofit a regular hat with a UV index sensor to remind them to re-slather on sunscreen.

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser
2 min read

Adafruit UV warning hat
This hat could be your sunblock reminder buddy. Video screenshot by Amanda Kooser/CNET

You're lounging on the beach in the sun with a good book. You're not worried because you already covered yourself from head to toe with sunscreen and have on a big straw hat. You get lost in the story as time ticks by. Suddenly, your hat begins to sing to you. It's a little ditty to remind you to put on some more sunscreen before you cook yourself. "Thanks, hat!" you think to yourself as you reach for the tube of sunblock.

You won't find this hat on Kickstarter or in a store. You'll have to make it yourself.

Electronics hobby site Adafruit gives instructions for DIYing the device using a hat of your choice, a $25 FLORA wearable electronics main board, a UV index sensor, a piezo buzzer, a battery, and conductive thread.

The step-by-step guide includes a circuit diagram and details on using the conductive thread, as well as how to install the UV index sensor. The instructions also show you how to set the device to play the Super Mario Bros theme, so you can one-up your sun protection. There's no soldering required, making it a project even beginners can tackle. The code can be customized to modify the UV threshold and to change the reminder interval.

Adafruit reminds makers that the circuit isn't waterproof, so you'll want to be careful not to dunk your high-tech hat in the pool or ocean waves. You could also adapt the design to work with a parasol or a beach bag. Whatever route you choose to go, you'll be doing yourself a big favor by avoiding having your swimsuit shape seared onto your back.