As a project for an embedded systems class, [Alan] recently built himself a sunrise-simulating alarm clock. You are probably familiar with these sorts of timepieces – they gradually light up the room to awaken the sleeping individual rather than jarring them awake with a buzzer or the radio. Since many commercial units with this feature are sold for $70 and up, his goal was to replicate the functionality at a fraction of the cost, using only open source components.
An Arm Cortex M3 processor runs the show, displaying the time via a pair of 8×8 LED matrix panels on the front of the device. The clock is programmed to gently wake up its user by simulating a sunrise over a period of 5, 15, 30, 45, or 60 minutes. If the user has not woken up before the sunrise simulation is complete, the clock resorts to a traditional piezo alarm to rouse the heavy sleeper.
The project is nicely done, and after looking at his bill of materials it seems to be far cheaper than many sunrise alarm clocks you will find in stores.