“I could not find a good name for this project. You could also call it an enough sleep timer. The idea for this project came up during a vacation in winter. We were in a vacation home where there was no alarm clock in the bed room. I normally need 8 hours of sleep but not more than that so when I wake up and I have slept for 8 hours, it is time for me to get out of bed. Unfortunately if you have no alarm clock and it is still dark outside, you need to use your watch or your smart phone - but the latter is not something I keep in my bedroom to see if you have slept long enough. In order not to have to look at my watch each time I wake up during the night and need my glasses to read the display this project was born.
I needed a device that could indicate if I had slept at least 8 hours without the need to be woken up by an alarm clock exactly after 8 hours. The device is a battery powered timer that does the simple thing to blink a LED 8 hours after the device is switched on. So when I wake up I can get out of bed if the LED is blinking and I should catch some extra sleep as long as it doesnt.
But this is not the only application. If you have small children that cannot yet tell the time yet, you can use this device to let them know they can get out of their bed as soon as the LED starts blinking.
Note that when the LED starts blinking it does not stop until you switch off the device.
As always I built this project around my favorite micro controller the PIC, using the JAL programming language but you can also use an Arduino.”