What it is:

This big (21 x 7.5cm display) LED Clock DIY Kit runs on an Arduino Nano, and you can either use the firmware* we provide for download, or program your own application. You could even combine it with our WWVB or DSF77 Atomic Clock receivers, if you feel skilled enough.

Specifications:

The following functions are included in the demo code. You can add more functions, remove them, or create your own code from scratch:

• 12 or 24 hour time
• date
• time only or date and date intermittent
• seconds on or off
• brief display of date by pressing the snooze button
• automatic display dimming (adjustable behavior by changing parameters in code)
• 3 independent alarms (off, weekdays, weekend, every day)
• alarm snooze (duration adjustable)

The code requires the following Arduino libraries:

• EEPROM.h
• TimerOne.h
• Wire.h
• RTClib.h
• TimeLib.h
• DS1307RTC.h
• If not already done, install the libraries using the library manager in your Arduino IDE.

Note:

The alarm function is only available when a melody chip is installed. The kit includes a socket for it to make switching the melody chip easy. You will find the 4 different melodies in our shop: Love Me Tender – Für Elise – Happy Birthday – Jingle Bells

Assembling:

The LEDs are dual-color types, producing green light in one polarity and red light in the other one. Depending on your taste, you can have the entire display red or green, or the seconds in a different color, or the colon and alarm LED, or what ever combination you think is cool. If you push a 3V lithium button cell between the leads of one of these LEDs, you can see how the colors will look like without blowing the LED up. Just don’t do it for longer then a second.

The clock is easy to assemble; all parts are through-hole and their positions are clearly printed on the PCB. Just match the part positions and the values from the schematic. After you finished the 2 separate circuit boards (the main board and the display board), you attach them using nice big solder blobs on both sides (top and bottom) of the main board. The image gallery shows you how to do this.

Assemble the photo resistor as the last part, after both PCBs are already connected, and align it with the hole in the front panel.

Now you load the code to your Arduino Nano module, and you are ready to go. The code should be uploaded when the Nano is on the board and the RTC backup battery is installed. This way, the RTC will set to the time and date of your computer.