BigBlue is a simple clock featuring double-sized digits and a one-button interface and an auto-dimming backlight.

Reset

Holding down the button when power is turned on, resets the configuration to defaults.

Configuration

A long press of the button (2 seconds - BTN_LongDownTimeout) when in time mode takes you to the configuration screens. On a given screen, tapping the button cycles through the options. There is no second button to step to the next screen. Instead a period of inactivity (5s - BTN_LongUpTimeout) advances.
The screens are

Format
 12Hr & A/P	eg 2:03P
 12Hr & Day	eg 2:03 Mon 3
 24Hr		eg 14:03
 24Hr & Day	eg 14:03 Mon 3

Sets the way time is display: 12 or 24 hour, A(M)/P(M) display or day and date.

Colon/Font>
 Solid or Blink/
 Original or Revised

Sets the display style: the ':' blinking or solid, the "font" either my original or revised one.

Lo Ambient [XX%]
 0%, 5%, ...75%

Sets the low ambient light level as a percentage in steps of 5%. XX% is the currently measured light level.

Lo Backlight
 (Off), Min, 5%, 10%, ...75%

Sets tbe low backlight level as a percentage in steps of 5%. The backlight reflects the value selected, except when Off. When Off and in all other configuration screens the backlight is the Hi value (below).

Hi Ambient [XX%]
 Lo + 5%, ...100%

Sets the high ambient light level as a percentage in steps of 5%. XX% is the currently measured light level.

Hi Backlight
 Lo + 5%, ...100%

Sets tbe high backlight level as a percentage in steps of 5%. The backlight reflects the value selected.

Hour
 00..23
Minute
 00..59
Day
 Mon, Tue, Wed, Thu, Fri, Sat, Sun
Date
 1..31
Month
 Jan, Feb, ... Nov, Dec
Year
 2010, 2011, ... 2020

These set the time and date.

Set
 HH:MM DD/MM/YY?

The final screen confirms the time and date. A button press saves the changes and sets the time. A long press cancels the changes.

Backlight

When running, BigBlue is constantly adjusting the backlight brightness based on the ambient light conditions. Lo and Hi Ambient and Backlight values are set in the configuration screens.

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.

When in the configurations screens the Hi backlight is used, except when setting the Hi or Lo backlight. The Hi backlight is also used instead of Off when setting the Lo backlight.

When in time mode, pressing the button will toggle "bypass backlight off" mode. This is disabled by default. When enabled, if the backlight would be Off due to the ambient light level, it will be set to Min instead.