- Knob 1: Rotate to change backlight brightness. Press and hold for 1-2s to enter time setting mode
- Knob 2: Click to change time display mode
- Switch 3: Controls alarm
When the clock is connected to power, a startup routine will run, slowly pulsing the backlights and moving all indicators to their maximum position and back, before continuing to normal operation. If the timekeeping was lost, the clock will instead switch to time setting mode.
Use this to confirm that all indicators move freely.
There is a yellow LED backlight installed in each display. Use Knob 1 to increase or decrease brightness. Rotate clockwise to increase and counter-clockwise to decrease backlight brightness. This setting persists, even if power is lost
The clock supports two modes to display time, digital and analog. Press Knob 2 to switch between these. This setting persists, even if power is lost.
- Digital display mode: Indicators will point to the current hour, minute and second and move in discrete steps as time moves on. So the seconds indicator will move once per seconds, the minute indicator once per minute and the hours indicator once per hour.
- Analog display mode: Indicators will move smoothly as time progresses.
Press and hold Knob 1 until the backlight LEDs start blinking (1-2 seconds). The clock will always switch to digital display mode to make setting the time easier. Rotate Knob 1 to set the hour, and Knob 2 to set the minute. Press Knob 1 again (a short click will be enough) to exit time setting mode. Seconds will always be reset to 0 and start counting again when the new time is confirmed.
Switch 3 has three positions:
- Up: Set alarm time
- Middle: Alarm disabled
- Down: Alarm armed
To set the alarm, move the Switch 3 to the up position. Use Knob 1 and Knob 2 to set the hour and minute of the alarm time. Note that the minutes can only be set in 5 min intervals.
While setting the alarm time, press Knob 2 to change the alarm melody. 6 different melodies are available
- Star Wars
- Game of Thrones
- Harry Potter
- Pirates of the Caribbean
- Tetris
- Mario
To save the alarm time, move Switch 3 to the middle or down position.
Alarm time and selected melody is persisted, even if power is lost.
Not used in normal operation.
Pressing Knob 2 for 1-2 seconds will enter calibration mode, backlight LEDs will start pulsing slowly. This mode is used to calibrate the displays, adjusting the display potentiometers on the circuit board until the indicators points to the end of the dial scale. Knob 1 will move the hour dial, Knob 2 will move the minutes and seconds dials.
Long pressing Knob 1 again for 1-2 seconds will exit this mode and normal operation will resume.
The clock includes a slot for a CR2032 3V coin cell battery to ensure time keeping even if main power is lost. To replace the battery, open the clock by removing the four (4) screws at the bottom of the clock and lifting off the outer case. Insert the coin cell battery into the holder located on the small module in the clock (see picture).
Ideally the clock is powered using a 5.5 X 2.1 jack with a 7-12V power supply, with ~7V being recommended.
Powering the clock via the USB B port (which only provides 5V) will also work, but the display will not be accurate as the backlight brightness will affect the indicators in this case.
Connecting a USB B cable to the clock, a serial monitor using a baud rate of 115200 will allow you to read the debug output of the clock.