An open-source, Arduino-powered smartwatch with a 1.54-inch e-paper screen. It’s called the watchy, and both the hardware and software are completely customizable. To top off, it’s only $ 50, on sale for $ 45 at time of writing.

There’s Wi-Fi, Bluetooth, a 3-axis accelerometer and four buttons that can be used for navigation, or whatever other functions you can dream up. The watch does n’t come assembled – you have to hook the 200×200 display, PCB, and 200mAh battery together.

The watch does come with pre-loaded software and pre-loaded software. If you want to make any changes to the watch face you’ll have to download the Arduino IDE and program them yourself yourself yourself.

If you want a watch with a case that looks like an iPod or game boy, you can 3D print a case and code the watch face yourself. It’s the type of freedom you’re not likely to get from most commercial smartwatches.

The battery life sqfmi estimates depends on your use case. It says if you’re just keeping time you should get five to seven days. But if you’ve got two to three to three days, you may only see two to 3.