The Dodow is a consumer device that aims to help users sleep, through biofeedback. The idea is to synchronise one’s breathing with the gentle rhythm of the device’s blue LEDs, which helps slow the heartrate and enables the user to more easily drift off to sleep. Noting that the device is essentially a breathing LED and little more, [Daniel Shiffman] set about building his own from scratch.

An ATTiny85 runs the show; no high-powered microcontrollers are necessary here. It’s hooked up to three 5mm blue LEDs, which are slowly ramped up and down to create a smooth, attractive breathing animation. The LEDs are directed upward so that their glow can be seen on the ceiling, allowing the user to lay on their back when getting ready for sleep. It’s all wrapped up in a 3D printed enclosure that is easily modifiable to suit a variety of battery solutions; [Daniel] chose the DL123A for its convenient voltage and battery life in this case. The design is available on Thingiverse for those looking to spin their own.

It’s a neat example of where DIY can really shine – reproducing a somewhat-expensive gadget that is overpriced for its fundamental simplicity. Now when it comes to waking up again, consider building yourself a nifty smart alarm clock.