The Dawn Clock
This project was embarked upon after buying (at some expense) two different alarm clocks that used a light source to simulate dawn breaking - accompanied by selectable sounds.
Neither worked satisfactorily. I wanted a realistic (and gentle) awakening to the morning sunrise, to be followed by bird, sea or lapping water. Anyhow, the proprietary devices were pretty poor. At best the lamps used reached max brilliance in about four levels and the sounds were predetermined and very artificial.
I wanted an alarm that produced a very gradual increase in light intensity (finally to be about 4,000 steps over a period of 1 to 30mins) and having reached maximum brillians, one of a series (nine were deemed enough) of pre-recorded sounds would play for a chosen duration (ie length depending on record time).
I based the design upon the 16F877, this had the necessary EEPROM and I/O needed. The display was a backlight LCD (standard Hitachi configuration - 2 rows x 16 chars). After much deliberation, I settled for the 'easy' option of using a Real Time Clock (RTC), freeing up processor time for the 'fun' bits!. For the sound generation I selected an MP3 module, as each of these devices were readily available and extremely affordable. |