Sleeper is a device that helps you fall asleep faster by reducing your breathing form 9 to 4 breaths per minute. It lightens and dims the LED so you know when you should inhale and exhale. You can set maximum brightness of LEDs and maximum time the device will be operating. After this time it will shut down every periphery and go to power-down mode to save battery. It can operate on single LiPo cell or two AA batteries or whatever gives the right voltage for ATtiny13.

It is based on the project FADing but it uses smaller and cheaper ATtiny13.

The device has three buttons: +, - and Mode. After powering up you can set maximum brightness and time for which the device will be operating. You increase brightness/time with + button and decrease with -. Mode button changes what you will modify at the moment (brightness or time). Maximum brightness is showed on one LED and time is symbolized on the other (brighter means longer). One increase in time is increase of one minute (same for decrease). After about 4 seconds from the + or - button push the device will blink twice and go to operating mode. In this mode you can select which LED will be used (during all operating time) with Mode button. Pulsations slowly decrease from 9 to 4 pulses per minute. After the time set earlier device turns off LEDs and go to power-down mode. You can start using it again by pressing any button and then following instructons from the beggining but this time it will remember your previos settings (brightness and time). You can manually put device into power-down mode by pressing both + and - button.

Schematics and PCB are available on CircuitMaker.

Program can be compiled with Atmel Studio 7 or other similar tool.

Output file has 1000 bytes which is 97.7% of ATtiny13 memory.