This is "BigBlue", a very simple clock using a DS1307 RTC and a 16-char/2-line (HD44780 compatible) LCD. The main features are:
- double-sized digits
- auto-dimming backlight
-
one-button interface
BigBlue Boxed by funnypolynomial, on Flickr
The box is technically a photo frame, the clear plastic front is actually two layers, all connected with magnets. In a way this is a "skeleton" clock: I'm deliberately exposing the guts and making the most of the colours (the boards, the ribbon cable etc).
BigBlue Pre-Assembly by funnypolynomial, on Flickr
Double-Sized Digits
I use the LCD's 8 user-definable characters to create 8 "tiles". I then combine these tiles in 2x2 groups to form digits (and a few letters) creating a clock which can be read at a distance.
BigBlue Font by funnypolynomial, on Flickr
Auto-Dimming Backlight
The LCD I'm using has a nice blue backlight but it's very bright, especially at night so I added an LDR and code to adjust the backlight based on the measured ambient light. As well as the time etc, the clock's configuration screens allow the setting of "Lo" and "Hi" Ambient and Backlight values
- if the ambient light is less than the Lo value, the Lo backlight level is used
- if the ambient light is greater than the Hi value, the Hi backlight level is used
- at ambient light levels in between, the backlight level is interpolated
BigBlue Auto-Dimming - YouTube
One-Button Interface
For simplicity, there is only one button. A long press of the button (2 seconds) when in time mode takes you to the configuration screens.
On a given screen, tapping the button cycles through the options.
A period of inactivity (5s) advances to the next screen automatically.
There are more photos and details on flickr:BigBlue | Flickr
The sketch is available from my site:Mark Wilson's Home Page - Software/Arduino/BigBlue