Automatic Alarm
This is an alarm machine that turns on and off music and controls its volume automatically based on “how bright is it now?” As this is totally independent from the time, this device may not wake you up on cloudy or rainy morning!
The photo resistor converts the brightness where it is installed into 0~255 number. When it’s still dark (0~49), this machine does nothing. However, when the dawn is just breaking (50~), this alarm begins playing music with minimum volume not to frighten users. The volume is increased proportionally to the brightness to wake users mildly.